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A Pair of TESS Planets Spanning the Radius Valley around the Nearby Mid-M Dwarf LTT 3780Cloutier, RyanEastman, Jason D.Rodriguez, Joseph E.Astudillo-Defru, NicolaBonfils, XavierMortier, AnneliesWatson, Christopher A.Stalport, ManuPinamonti, MatteoLienhard, FlorianHarutyunyan, AvetDamasso, MarioLatham, David W.Collins, Karen A.Massey, RobertIrwin, JonathanWinters, Jennifer G.Charbonneau, DavidZiegler, CarlMatthews, ElisabethCrossfield, Ian J. M.Kreidberg, LauraQuinn, Samuel N.Ricker, GeorgeVanderspek, RolandSeager, SaraWinn, JoshuaJenkins, Jon M.Vezie, MichaelUdry, StéphaneTwicken, Joseph D.Tenenbaum, PeterSozzetti, AlessandroSégransan, DamienSchlieder, Joshua E.Sasselov, DimitarSantos, Nuno C.Rice, KenRackham, Benjamin V.Poretti, EnnioPiotto, GiampaoloPhillips, DavidPepe, FrancescoMolinari, EmilioMignon, LucileMicela, GiuseppinaMelo, Claudiode Medeiros, José R.Mayor, MichelMatson, Rachel A.Martinez Fiorenzano, Aldo F.Mann, Andrew W.Magazzú, AntonioLovis, ChristopheLópez-Morales, MercedesLopez, EricLissauer, Jack J.Lépine, SébastienLaw, NicholasKielkopf, John F.Johnson, John A.Jensen, Eric L. N.Howell, Steve B.Gonzales, EricaGhedina, AdrianoForveille, ThierryFigueira, PedroDumusque, XavierDressing, Courtney D.Doyon, RenéDíaz, Rodrigo F.Fabrizio, Luca DiDelfosse, XavierCosentino, RosarioConti, Dennis M.Collins, Kevin I.Cameron, Andrew CollierCiardi, DavidCaldwell, Douglas A.Burke, ChristopherBuchhave, LarsBriceño, CésarBoyd, PatriciaBouchy, FrançoisBeichman, CharlesArtigau, ÉtienneAlmenara, Jose M.DOI: info:10.3847/1538-3881/ab91c2v. 160No. 13
Cloutier, Ryan, Eastman, Jason D., Rodriguez, Joseph E., Astudillo-Defru, Nicola, Bonfils, Xavier, Mortier, Annelies, Watson, Christopher A., Stalport, Manu, Pinamonti, Matteo, Lienhard, Florian, Harutyunyan, Avet, Damasso, Mario, Latham, David W., Collins, Karen A., Massey, Robert, Irwin, Jonathan, Winters, Jennifer G., Charbonneau, David, Ziegler, Carl, Matthews, Elisabeth, Crossfield, Ian J. M., Kreidberg, Laura, Quinn, Samuel N., Ricker, George, Vanderspek, Roland et al. 2020. "A Pair of TESS Planets Spanning the Radius Valley around the Nearby Mid-M Dwarf LTT 3780." The Astronomical Journal 160 (1):3. https://doi.org/10.3847/1538-3881/ab91c2
ID: 157584
Type: article
Authors: Cloutier, Ryan; Eastman, Jason D.; Rodriguez, Joseph E.; Astudillo-Defru, Nicola; Bonfils, Xavier; Mortier, Annelies; Watson, Christopher A.; Stalport, Manu; Pinamonti, Matteo; Lienhard, Florian; Harutyunyan, Avet; Damasso, Mario; Latham, David W.; Collins, Karen A.; Massey, Robert; Irwin, Jonathan; Winters, Jennifer G.; Charbonneau, David; Ziegler, Carl; Matthews, Elisabeth; Crossfield, Ian J. M.; Kreidberg, Laura; Quinn, Samuel N.; Ricker, George; Vanderspek, Roland; Seager, Sara; Winn, Joshua; Jenkins, Jon M.; Vezie, Michael; Udry, Stéphane; Twicken, Joseph D.; Tenenbaum, Peter; Sozzetti, Alessandro; Ségransan, Damien; Schlieder, Joshua E.; Sasselov, Dimitar; Santos, Nuno C.; Rice, Ken; Rackham, Benjamin V.; Poretti, Ennio; Piotto, Giampaolo; Phillips, David; Pepe, Francesco; Molinari, Emilio; Mignon, Lucile; Micela, Giuseppina; Melo, Claudio; de Medeiros, José R.; Mayor, Michel; Matson, Rachel A.; Martinez Fiorenzano, Aldo F.; Mann, Andrew W.; Magazzú, Antonio; Lovis, Christophe; López-Morales, Mercedes; Lopez, Eric; Lissauer, Jack J.; Lépine, Sébastien; Law, Nicholas; Kielkopf, John F.; Johnson, John A.; Jensen, Eric L. N.; Howell, Steve B.; Gonzales, Erica; Ghedina, Adriano; Forveille, Thierry; Figueira, Pedro; Dumusque, Xavier; Dressing, Courtney D.; Doyon, René; Díaz, Rodrigo F.; Fabrizio, Luca Di; Delfosse, Xavier; Cosentino, Rosario; Conti, Dennis M.; Collins, Kevin I.; Cameron, Andrew Collier; Ciardi, David; Caldwell, Douglas A.; Burke, Christopher; Buchhave, Lars; Briceño, César; Boyd, Patricia; Bouchy, François; Beichman, Charles; Artigau, Étienne; Almenara, Jose M.
Abstract: We present the confirmation of two new planets transiting the nearby mid-M dwarf LTT 3780 (TIC 36724087, TOI-732, V = 13.07, Ks = 8.204, Rs = 0.374 R, Ms = 0.401 M, d = 22 pc). The two planet candidates are identified in a single Transiting Exoplanet Survey Satellite sector and validated with reconnaissance spectroscopy, ground-based photometric follow-up, and high-resolution imaging. With measured orbital periods of Pb = 0.77, Pc = 12.25 days and sizes rp,b = 1.33 ± 0.07, rp,c = 2.30 ± 0.16 R, the two planets span the radius valley in period-radius space around low-mass stars, thus making the system a laboratory to test competing theories of the emergence of the radius valley in that stellar mass regime. By combining 63 precise radial velocity measurements from the High Accuracy Radial velocity Planet Searcher (HARPS) and HARPS-N, we measure planet masses of ${m}_{p,b}={2.62}_{-0.46}^{+0.48}$ and ${m}_{p,c}={8.6}_{-1.3}^{+1.6}$ M, which indicates that LTT 3780b has a bulk composition consistent with being Earth-like, while LTT 3780c likely hosts an extended H/He envelope. We show that the recovered planetary masses are consistent with predictions from both photoevaporation and core-powered mass-loss models. The brightness and small size of LTT 3780, along with the measured planetary parameters, render LTT 3780b and c as accessible targets for atmospheric characterization of planets within the same planetary system and spanning the radius valley.
TOI-1235 b: A Keystone Super-Earth for Testing Radius Valley Emergence Models around Early M DwarfsCloutier, RyanRodriguez, Joseph E.Irwin, JonathanCharbonneau, DavidStassun, Keivan G.Mortier, AnneliesLatham, David W.Isaacson, HowardHoward, Andrew W.Udry, StéphaneWilson, Thomas G.Watson, Christopher A.Pinamonti, MatteoLienhard, FlorianGiacobbe, PaoloGuerra, PereCollins, Karen A.Beiryla, AllysonEsquerdo, Gilbert A.Matthews, ElisabethMatson, Rachel A.Howell, Steve B.Furlan, EliseCrossfield, Ian J. M.Winters, Jennifer G.Nava, ChantanelleMent, KristoLopez, Eric D.Ricker, GeorgeVanderspek, RolandSeager, SaraJenkins, Jon M.Ting, Eric B.Tenenbaum, PeterSozzetti, AlessandroSha, LizhouSégransan, DamienSchlieder, Joshua E.Sasselov, DimitarRoy, ArpitaRobertson, PaulRice, KenPoretti, EnnioPiotto, GiampaoloPhillips, DavidPepper, JoshuaPepe, FrancescoMolinari, EmilioMocnik, TeoMicela, GiuseppinaMayor, MichelMartinez Fiorenzano, Aldo F.Mallia, FrancoLubin, JackLovis, ChristopheLópez-Morales, MercedesKosiarek, Molly R.Kielkopf, John F.Kane, Stephen R.Jensen, Eric L. N.Isopi, GiovanniHuber, DanielHill, Michelle L.Harutyunyan, AvetGonzales, EricaGiacalone, StevenGhedina, AdrianoErcolino, AndreaDumusque, XavierDressing, Courtney D.Damasso, MarioDalba, Paul A.Cosentino, RosarioConti, Dennis M.Colón, Knicole D.Collins, Kevin I.Cameron, Andrew CollierCiardi, DavidChristiansen, JessieChontos, AshleyCecconi, MassimoCaldwell, Douglas A.Burke, ChristopherBuchhave, LarsBeichman, CharlesBehmard, AidaBeard, CoreyAkana Murphy, Joseph M.DOI: info:10.3847/1538-3881/ab9534v. 160No. 122
Cloutier, Ryan, Rodriguez, Joseph E., Irwin, Jonathan, Charbonneau, David, Stassun, Keivan G., Mortier, Annelies, Latham, David W., Isaacson, Howard, Howard, Andrew W., Udry, Stéphane, Wilson, Thomas G., Watson, Christopher A., Pinamonti, Matteo, Lienhard, Florian, Giacobbe, Paolo, Guerra, Pere, Collins, Karen A., Beiryla, Allyson, Esquerdo, Gilbert A., Matthews, Elisabeth, Matson, Rachel A., Howell, Steve B., Furlan, Elise, Crossfield, Ian J. M., Winters, Jennifer G. et al. 2020. "TOI-1235 b: A Keystone Super-Earth for Testing Radius Valley Emergence Models around Early M Dwarfs." The Astronomical Journal 160 (1):22. https://doi.org/10.3847/1538-3881/ab9534
ID: 157585
Type: article
Authors: Cloutier, Ryan; Rodriguez, Joseph E.; Irwin, Jonathan; Charbonneau, David; Stassun, Keivan G.; Mortier, Annelies; Latham, David W.; Isaacson, Howard; Howard, Andrew W.; Udry, Stéphane; Wilson, Thomas G.; Watson, Christopher A.; Pinamonti, Matteo; Lienhard, Florian; Giacobbe, Paolo; Guerra, Pere; Collins, Karen A.; Beiryla, Allyson; Esquerdo, Gilbert A.; Matthews, Elisabeth; Matson, Rachel A.; Howell, Steve B.; Furlan, Elise; Crossfield, Ian J. M.; Winters, Jennifer G.; Nava, Chantanelle; Ment, Kristo; Lopez, Eric D.; Ricker, George; Vanderspek, Roland; Seager, Sara; Jenkins, Jon M.; Ting, Eric B.; Tenenbaum, Peter; Sozzetti, Alessandro; Sha, Lizhou; Ségransan, Damien; Schlieder, Joshua E.; Sasselov, Dimitar; Roy, Arpita; Robertson, Paul; Rice, Ken; Poretti, Ennio; Piotto, Giampaolo; Phillips, David; Pepper, Joshua; Pepe, Francesco; Molinari, Emilio; Mocnik, Teo; Micela, Giuseppina; Mayor, Michel; Martinez Fiorenzano, Aldo F.; Mallia, Franco; Lubin, Jack; Lovis, Christophe; López-Morales, Mercedes; Kosiarek, Molly R.; Kielkopf, John F.; Kane, Stephen R.; Jensen, Eric L. N.; Isopi, Giovanni; Huber, Daniel; Hill, Michelle L.; Harutyunyan, Avet; Gonzales, Erica; Giacalone, Steven; Ghedina, Adriano; Ercolino, Andrea; Dumusque, Xavier; Dressing, Courtney D.; Damasso, Mario; Dalba, Paul A.; Cosentino, Rosario; Conti, Dennis M.; Colón, Knicole D.; Collins, Kevin I.; Cameron, Andrew Collier; Ciardi, David; Christiansen, Jessie; Chontos, Ashley; Cecconi, Massimo; Caldwell, Douglas A.; Burke, Christopher; Buchhave, Lars; Beichman, Charles; Behmard, Aida; Beard, Corey; Akana Murphy, Joseph M.
Abstract: Small planets on close-in orbits tend to exhibit envelope mass fractions of either effectively zero or up to a few percent depending on their size and orbital period. Models of thermally driven atmospheric mass loss and of terrestrial planet formation in a gas-poor environment make distinct predictions regarding the location of this rocky/nonrocky transition in period-radius space. Here we present the confirmation of TOI-1235 b (P = 3.44 days, ${r}_{{\rm{p}}}={1.738}_{-0.076}^{+0.087}$ ${R}_{\oplus }$ ), a planet whose size and period are intermediate between the competing model predictions, thus making the system an important test case for emergence models of the rocky/nonrocky transition around early M dwarfs (Rs = 0.630 ± 0.015 ${R}_{\odot }$ , Ms = 0.640 ± 0.016 ${M}_{\odot }$ ). We confirm the TESS planet discovery using reconnaissance spectroscopy, ground-based photometry, high-resolution imaging, and a set of 38 precise radial velocities (RVs) from HARPS-N and HIRES. We measure a planet mass of ${6.91}_{-0.85}^{+0.75}$ ${M}_{\oplus }$ , which implies an iron core mass fraction of ${20}_{-12}^{+15}$ % in the absence of a gaseous envelope. The bulk composition of TOI-1235 b is therefore consistent with being Earth-like, and we constrain an H/He envelope mass fraction to be <0.5% at 90% confidence. Our results are consistent with model predictions from thermally driven atmospheric mass loss but not with gas-poor formation, suggesting that the former class of processes remains efficient at sculpting close-in planets around early M dwarfs. Our RV analysis also reveals a strong periodicity close to the first harmonic of the photometrically determined stellar rotation period that we treat as stellar activity, despite other lines of evidence favoring a planetary origin ( $P={21.8}_{-0.8}^{+0.9}$ days, ${m}_{{\rm{p}}}\sin i={13.0}_{-5.3}^{+3.8}$ ${M}_{\oplus }$ ) that cannot be firmly ruled out by our data.
An ultra-short period rocky super-Earth orbiting the G2-star HD 80653Frustagli, G.Poretti, E.Milbourne, TimothyMalavolta, L.Mortier, A.Singh, V.Bonomo, A. S.Buchhave, L. A.Zeng, L.Vanderburg, AndrewUdry, S.Andreuzzi, G.Collier-Cameron, A.Cosentino, R.Damasso, M.Ghedina, A.Harutyunyan, A.Haywood, Raphaëlle D.Latham, David W.López-Morales, MercedesLorenzi, V.Martinez Fiorenzano, A. F.Mayor, M.Micela, G.Molinari, E.Pepe, F.Phillips, DavidRice, K.Sozzetti, A.DOI: info:10.1051/0004-6361/201936689v. 633A133
Frustagli, G., Poretti, E., Milbourne, Timothy, Malavolta, L., Mortier, A., Singh, V., Bonomo, A. S., Buchhave, L. A., Zeng, L., Vanderburg, Andrew, Udry, S., Andreuzzi, G., Collier-Cameron, A., Cosentino, R., Damasso, M., Ghedina, A., Harutyunyan, A., Haywood, Raphaëlle D., Latham, David W., López-Morales, Mercedes, Lorenzi, V., Martinez Fiorenzano, A. F., Mayor, M., Micela, G., Molinari, E. et al. 2020. "An ultra-short period rocky super-Earth orbiting the G2-star HD 80653." Astronomy and Astrophysics 633:A133. https://doi.org/10.1051/0004-6361/201936689
ID: 155671
Type: article
Authors: Frustagli, G.; Poretti, E.; Milbourne, Timothy; Malavolta, L.; Mortier, A.; Singh, V.; Bonomo, A. S.; Buchhave, L. A.; Zeng, L.; Vanderburg, Andrew; Udry, S.; Andreuzzi, G.; Collier-Cameron, A.; Cosentino, R.; Damasso, M.; Ghedina, A.; Harutyunyan, A.; Haywood, Raphaëlle D.; Latham, David W.; López-Morales, Mercedes; Lorenzi, V.; Martinez Fiorenzano, A. F.; Mayor, M.; Micela, G.; Molinari, E.; Pepe, F.; Phillips, David; Rice, K.; Sozzetti, A.
Abstract: Ultra-short period (USP) planets are a class of exoplanets with periods shorter than one day. The origin of this sub-population of planets is still unclear, with different formation scenarios highly dependent on the composition of the USP planets. A better understanding of this class of exoplanets will, therefore, require an increase in the sample of such planets that have accurate and precise masses and radii, which also includes estimates of the level of irradiation and information about possible companions. Here we report a detailed characterization of a USP planet around the solar-type star HD 80653 ≡EP 251279430 using the K2 light curve and 108 precise radial velocities obtained with the HARPS-N spectrograph, installed on the Telescopio Nazionale Galileo. From the K2 C16 data, we found one super-Earth planet (Rb = 1.613 ± 0.071 R) transiting the star on a short-period orbit (Pb = 0.719573 ± 0.000021 d). From our radial velocity measurements, we constrained the mass of HD 80653 b to Mb = 5.60 ± 0.43 M. We also detected a clear long-term trend in the radial velocity data. We derived the fundamental stellar parameters and determined a radius of R = 1.22 ± 0.01 R and mass of M = 1.18 ± 0.04 M, suggesting that HD 80653 has an age of 2.7 ± 1.2 Gyr. The bulk density (ρb = 7.4 ± 1.1 g cm-3) of the planet is consistent with an Earth-like composition of rock and iron with no thick atmosphere. Our analysis of the K2 photometry also suggests hints of a shallow secondary eclipse with a depth of 8.1 ± 3.7 ppm. Flux variations along the orbital phase are consistent with zero. The most important contribution might come from the day-side thermal emission from the surface of the planet at T ~ 3480 K. HARPS-N spectroscopic data are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz- bin/cat/J/A+A/633/A133 Based on observations made with the Italian Telescopio Nazionale Galileo (TNG) operated by the Fundación Galileo Galilei (FGG) of the Istituto Nazionale di Astrofisica (INAF) at the Observatorio del Roque de los Muchachos (La Palma, Canary Islands, Spain).
Erratum: An 11 Earth-mass, Long-period Sub-Neptune Orbiting a Sun-like Star (2019, AJ, 158, 165)Mayo, Andrew W.Rajpaul, Vinesh M.Buchhave, Lars A.Dressing, Courtney D.Mortier, AnneliesZeng, LiFortenbach, Charles D.Aigrain, SuzanneBonomo, Aldo S.Collier Cameron, AndrewCharbonneau, DavidCoffinet, AdrienCosentino, RosarioDamasso, MarioDumusque, XavierMartinez Fiorenzano, A. F.Haywood, Raphaëlle D.Latham, David W.López-Morales, MercedesMalavolta, LucaMicela, GiusiMolinari, EmilioPearce, LoganPepe, FrancescoPhillips, DavidPiotto, GiampaoloPoretti, EnnioRice, KenSozzetti, AlessandroUdry, StephaneDOI: info:10.3847/1538-3881/ab5e5ev. 15934
Mayo, Andrew W., Rajpaul, Vinesh M., Buchhave, Lars A., Dressing, Courtney D., Mortier, Annelies, Zeng, Li, Fortenbach, Charles D., Aigrain, Suzanne, Bonomo, Aldo S., Collier Cameron, Andrew, Charbonneau, David, Coffinet, Adrien, Cosentino, Rosario, Damasso, Mario, Dumusque, Xavier, Martinez Fiorenzano, A. F., Haywood, Raphaëlle D., Latham, David W., López-Morales, Mercedes, Malavolta, Luca, Micela, Giusi, Molinari, Emilio, Pearce, Logan, Pepe, Francesco, Phillips, David et al. 2020. "Erratum: "An 11 Earth-mass, Long-period Sub-Neptune Orbiting a Sun-like Star" (2019, AJ, 158, 165)." The Astronomical Journal 159:34. https://doi.org/10.3847/1538-3881/ab5e5e
ID: 155703
Type: article
Authors: Mayo, Andrew W.; Rajpaul, Vinesh M.; Buchhave, Lars A.; Dressing, Courtney D.; Mortier, Annelies; Zeng, Li; Fortenbach, Charles D.; Aigrain, Suzanne; Bonomo, Aldo S.; Collier Cameron, Andrew; Charbonneau, David; Coffinet, Adrien; Cosentino, Rosario; Damasso, Mario; Dumusque, Xavier; Martinez Fiorenzano, A. F.; Haywood, Raphaëlle D.; Latham, David W.; López-Morales, Mercedes; Malavolta, Luca; Micela, Giusi; Molinari, Emilio; Pearce, Logan; Pepe, Francesco; Phillips, David; Piotto, Giampaolo; Poretti, Ennio; Rice, Ken; Sozzetti, Alessandro; Udry, Stephane
Testing the Spectroscopic Extraction of Suppression of Convective BlueshiftMiklos, M.Milbourne, Timothy W.Haywood, Raphaëlle D.Phillips, David F.Saar, Steven H.Meunier, N.Cegla, H. M.Dumusque, X.Langellier, NicholasMaldonado, J.Malavolta, L.Mortier, A.Thompson, S.Watson, C. A.Cecconi, M.Cosentino, R.Ghedina, A.Li, C. -HLópez-Morales, MercedesMolinari, E.Poretti, EnnioSasselov, DimitarSozzetti, A.Walsworth, Ronald L.DOI: info:10.3847/1538-4357/ab59d5v. 888117
Miklos, M., Milbourne, Timothy W., Haywood, Raphaëlle D., Phillips, David F., Saar, Steven H., Meunier, N., Cegla, H. M., Dumusque, X., Langellier, Nicholas, Maldonado, J., Malavolta, L., Mortier, A., Thompson, S., Watson, C. A., Cecconi, M., Cosentino, R., Ghedina, A., Li, C. -H, López-Morales, Mercedes, Molinari, E., Poretti, Ennio, Sasselov, Dimitar, Sozzetti, A., and Walsworth, Ronald L. 2020. "Testing the Spectroscopic Extraction of Suppression of Convective Blueshift." The Astrophysical Journal 888:117. https://doi.org/10.3847/1538-4357/ab59d5
ID: 155695
Type: article
Authors: Miklos, M.; Milbourne, Timothy W.; Haywood, Raphaëlle D.; Phillips, David F.; Saar, Steven H.; Meunier, N.; Cegla, H. M.; Dumusque, X.; Langellier, Nicholas; Maldonado, J.; Malavolta, L.; Mortier, A.; Thompson, S.; Watson, C. A.; Cecconi, M.; Cosentino, R.; Ghedina, A.; Li, C. -H; López-Morales, Mercedes; Molinari, E.; Poretti, Ennio; Sasselov, Dimitar; Sozzetti, A.; Walsworth, Ronald L.
Abstract: Efforts to detect low-mass exoplanets using stellar radial velocities (RVs) are currently limited by magnetic photospheric activity. Suppression of convective blueshift is the dominant magnetic contribution to RV variability in low-activity Sun-like stars. Due to convective plasma motion, the magnitude of RV contributions from the suppression of convective blueshift is related to the depth of formation of photospheric spectral lines for a given species used to compute the RV time series. Meunier et al. used this relation to demonstrate a method for spectroscopic extraction of the suppression of convective blueshift in order to isolate RV contributions, including planetary RVs, that contribute equally to the time series for each spectral line. Here, we extract disk-integrated solar RVs from observations over a 2.5 yr time span made with the solar telescope integrated with the HARPS-N spectrograph at the Telescopio Nazionale Galileo (La Palma, Canary Islands, Spain). We apply the methods outlined by Meunier et al. We are not, however, able to isolate physically meaningful contributions due to the suppression of convective blueshift from this solar data set, potentially because our data set is taken during solar minimum when the suppression of convective blueshift may not sufficiently dominate activity contributions to RVs. This result indicates that, for low- activity Sun-like stars, one must include additional RV contributions from activity sources not considered in the Meunier et al. model at different timescales, as well as instrumental variation, in order to reach the submeter per second RV sensitivity necessary to detect low- mass planets in orbit around Sun-like stars.
K2-111: an old system with two planets in near-resonanceMortier, A.Zapatero Osorio, M. R.Malavolta, L.Alibert, Y.Rice, K.Lillo-Box, J.Vanderburg, A.Oshagh, M.Buchhave, L.Adibekyan, V.Delgado Mena, E.Lopez-Morales, MercedesCharbonneau, DavidSousa, S. G.Lovis, C.Affer, L.Allende Prieto, C.Barros, S. C. C.Benatti, S.Bonomo, A. S.Boschin, W.Bouchy, F.Cabral, A.Collier Cameron, A.Cosentino, R.Cristiani, S.Demangeon, O. D. S.Di Marcantonio, P.D'Odorico, V.Dumusque, X.Ehrenreich, D.Figueira, P.Fiorenzano, A.Ghedina, A.González Hernández, J. I.Haldemann, J.Harutyunyan, A.Haywood, Raphaëlle D.Latham, David W.Lavie, B.Lo Curto, G.Maldonado, J.Manescau, A.Martins, C. J. A. P.Mayor, M.Mégevand, D.Mehner, A.Micela, G.Molaro, P.Molinari, E.Nunes, N. J.Pepe, F. A.Palle, E.Phillips, DavidPiotto, G.Pinamonti, M.Poretti, E.Riva, M.Rebolo, R.Santos, N. C.Sasselov, DimitarSozzetti, A.Suárez Mascareño, A.Udry, S.West, R. G.Watson, C. A.Wilson, T. G.DOI: info:10.1093/mnras/staa3144v. 4995004–5021
Mortier, A., Zapatero Osorio, M. R., Malavolta, L., Alibert, Y., Rice, K., Lillo-Box, J., Vanderburg, A., Oshagh, M., Buchhave, L., Adibekyan, V., Delgado Mena, E., Lopez-Morales, Mercedes, Charbonneau, David, Sousa, S. G., Lovis, C., Affer, L., Allende Prieto, C., Barros, S. C. C., Benatti, S., Bonomo, A. S., Boschin, W., Bouchy, F., Cabral, A., Collier Cameron, A., Cosentino, R. et al. 2020. "K2-111: an old system with two planets in near-resonance." Monthly Notices of the Royal Astronomical Society 499:5004– 5021. https://doi.org/10.1093/mnras/staa3144
ID: 158737
Type: article
Authors: Mortier, A.; Zapatero Osorio, M. R.; Malavolta, L.; Alibert, Y.; Rice, K.; Lillo-Box, J.; Vanderburg, A.; Oshagh, M.; Buchhave, L.; Adibekyan, V.; Delgado Mena, E.; Lopez-Morales, Mercedes; Charbonneau, David; Sousa, S. G.; Lovis, C.; Affer, L.; Allende Prieto, C.; Barros, S. C. C.; Benatti, S.; Bonomo, A. S.; Boschin, W.; Bouchy, F.; Cabral, A.; Collier Cameron, A.; Cosentino, R.; Cristiani, S.; Demangeon, O. D. S.; Di Marcantonio, P.; D'Odorico, V.; Dumusque, X.; Ehrenreich, D.; Figueira, P.; Fiorenzano, A.; Ghedina, A.; González Hernández, J. I.; Haldemann, J.; Harutyunyan, A.; Haywood, Raphaëlle D.; Latham, David W.; Lavie, B.; Lo Curto, G.; Maldonado, J.; Manescau, A.; Martins, C. J. A. P.; Mayor, M.; Mégevand, D.; Mehner, A.; Micela, G.; Molaro, P.; Molinari, E.; Nunes, N. J.; Pepe, F. A.; Palle, E.; Phillips, David; Piotto, G.; Pinamonti, M.; Poretti, E.; Riva, M.; Rebolo, R.; Santos, N. C.; Sasselov, Dimitar; Sozzetti, A.; Suárez Mascareño, A.; Udry, S.; West, R. G.; Watson, C. A.; Wilson, T. G.
Abstract: This paper reports on the detailed characterization of the K2-111 planetary system with K2, WASP, and ASAS-SN photometry, as well as high-resolution spectroscopic data from HARPS-N and ESPRESSO. The host, K2-111, is confirmed to be a mildly evolved (log g = 4.17), iron-poor ([Fe/H] = -0.46), but alpha-enhanced ([a/Fe]=0.27), chromospherically quiet, very old thick disc G2 star. A global fit, performed by using PyORBIT, shows that the transiting planet, K2-111 b, orbits with a period Pb = 5.3518 ± 0.0004 d and has a planet radius of $1.82^{+0.11}_{-0.09}$ R? and a mass of $5.29^{+0.76}_{-0.77}$ M?, resulting in a bulk density slightly lower than that of the Earth. The stellar chemical composition and the planet properties are consistent with K2-111 b being a terrestrial planet with an iron core mass fraction lower than the Earth. We announce the existence of a second signal in the radial velocity data that we attribute to a non-transiting planet, K2-111 c, with an orbital period of 15.6785 ± 0.0064 d, orbiting in near-3:1 mean motion resonance with the transiting planet, and a minimum planet mass of 11.3 ± 1.1 M?. Both planet signals are independently detected in the HARPS-N and ESPRESSO data when fitted separately. There are potentially more planets in this resonant system, but more well-sampled data are required to confirm their presence and physical parameters.
The spectral impact of magnetic activity on disc-integrated HARPS-N solar observations: exploring new activity indicatorsThompson, A. P. G.Watson, C. A.Haywood, Raphaëlle D.Costes, J. C.de Mooij, E.Collier Cameron, A.Dumusque, X.Phillips, David F.Saar, Steven H.Mortier, A.Milbourne, T. W.Aigrain, S.Cegla, H. M.Charbonneau, DavidCosentino, R.Ghedina, A.Latham, David W.López-Morales, M.Micela, G.Molinari, E.Poretti, E.Sozzetti, A.Thompson, S.Walsworth, Ronald L.DOI: info:10.1093/mnras/staa1010v. 4944279–4290
Thompson, A. P. G., Watson, C. A., Haywood, Raphaëlle D., Costes, J. C., de Mooij, E., Collier Cameron, A., Dumusque, X., Phillips, David F., Saar, Steven H., Mortier, A., Milbourne, T. W., Aigrain, S., Cegla, H. M., Charbonneau, David, Cosentino, R., Ghedina, A., Latham, David W., López-Morales, M., Micela, G., Molinari, E., Poretti, E., Sozzetti, A., Thompson, S., and Walsworth, Ronald L. 2020. "The spectral impact of magnetic activity on disc-integrated HARPS-N solar observations: exploring new activity indicators." Monthly Notices of the Royal Astronomical Society 494:4279– 4290. https://doi.org/10.1093/mnras/staa1010
ID: 157129
Type: article
Authors: Thompson, A. P. G.; Watson, C. A.; Haywood, Raphaëlle D.; Costes, J. C.; de Mooij, E.; Collier Cameron, A.; Dumusque, X.; Phillips, David F.; Saar, Steven H.; Mortier, A.; Milbourne, T. W.; Aigrain, S.; Cegla, H. M.; Charbonneau, David; Cosentino, R.; Ghedina, A.; Latham, David W.; López-Morales, M.; Micela, G.; Molinari, E.; Poretti, E.; Sozzetti, A.; Thompson, S.; Walsworth, Ronald L.
Abstract: Stellar activity is the major roadblock on the path to finding true Earth-analogue planets with the Doppler technique. Thus, identifying new indicators that better trace magnetic activity (I.e. faculae and spots) is crucial to aid in disentangling these signals from that of a planet's Doppler wobble. In this work, we investigate activity related features as seen in disc-integrated spectra from the HARPS-N solar telescope. We divide high-activity spectral echelle orders by low-activity master templates (as defined using both $\log {R^{\prime }_{HK}}$ and images from the Solar Dynamics Observatory, SDO), creating 'relative spectra'. With resolved images of the surface of the Sun (via SDO), the faculae and spot filling factors can be calculated, giving a measure of activity independent of, and in addition to, $\log {R^{\prime }_{HK}}$ . We find pseudo-emission (and pseudo-absorption) features in the relative spectra that are similar to those reported in our previous work on α Cen B. In α Cen B, the features are shown to correlate better to changes in faculae filling factor than spot filling factor. In this work, we more confidently identify changes in faculae coverage of the visible hemisphere of the Sun as the source of features produced in the relative spectra. Finally, we produce trailed spectra to observe the radial velocity component of the features, which show that the features move in a redward direction as one would expect when tracking active regions rotating on the surface of a star.
A giant impact as the likely origin of different twins in the Kepler-107 exoplanet systemBonomo, Aldo S.Zeng, LiDamasso, MarioLeinhardt, Zoë M.Justesen, Anders B.Lopez, EricLund, Mikkel N.Malavolta, LucaSilva Aguirre, VictorBuchhave, Lars A.Corsaro, EnricoDenman, ThomasLopez-Morales, MercedesMills, Sean M.Mortier, AnneliesRice, KenSozzetti, AlessandroVanderburg, AndrewAffer, LauraArentoft, TorbenBenbakoura, MansourBouchy, FrançoisChristensen-Dalsgaard, JørgenCollier Cameron, AndrewCosentino, RosarioDressing, Courtney D.Dumusque, XavierFigueira, PedroFiorenzano, Aldo F. M.García, Rafael A.Handberg, RasmusHarutyunyan, AvetJohnson, John A.Kjeldsen, HansLatham, David W.Lovis, ChristopheLundkvist, Mia S.Mathur, SavitaMayor, MichelMicela, GiusiMolinari, EmilioMotalebi, FatemehNascimbeni, ValerioNava, ChantanellePepe, FrancescoPhillips, David F.Piotto, GiampaoloPoretti, EnnioSasselov, DimitarSégransan, DamienUdry, StéphaneWatson, ChrisDOI: info:10.1038/s41550-018-0684-9v. 3416–423
Bonomo, Aldo S., Zeng, Li, Damasso, Mario, Leinhardt, Zoë M., Justesen, Anders B., Lopez, Eric, Lund, Mikkel N., Malavolta, Luca, Silva Aguirre, Victor, Buchhave, Lars A., Corsaro, Enrico, Denman, Thomas, Lopez-Morales, Mercedes, Mills, Sean M., Mortier, Annelies, Rice, Ken, Sozzetti, Alessandro, Vanderburg, Andrew, Affer, Laura, Arentoft, Torben, Benbakoura, Mansour, Bouchy, François, Christensen-Dalsgaard, Jørgen, Collier Cameron, Andrew, Cosentino, Rosario et al. 2019. "A giant impact as the likely origin of different twins in the Kepler-107 exoplanet system." Nature Astronomy 3:416– 423. https://doi.org/10.1038/s41550-018-0684-9
ID: 155447
Type: article
Authors: Bonomo, Aldo S.; Zeng, Li; Damasso, Mario; Leinhardt, Zoë M.; Justesen, Anders B.; Lopez, Eric; Lund, Mikkel N.; Malavolta, Luca; Silva Aguirre, Victor; Buchhave, Lars A.; Corsaro, Enrico; Denman, Thomas; Lopez-Morales, Mercedes; Mills, Sean M.; Mortier, Annelies; Rice, Ken; Sozzetti, Alessandro; Vanderburg, Andrew; Affer, Laura; Arentoft, Torben; Benbakoura, Mansour; Bouchy, François; Christensen-Dalsgaard, Jørgen; Collier Cameron, Andrew; Cosentino, Rosario; Dressing, Courtney D.; Dumusque, Xavier; Figueira, Pedro; Fiorenzano, Aldo F. M.; García, Rafael A.; Handberg, Rasmus; Harutyunyan, Avet; Johnson, John A.; Kjeldsen, Hans; Latham, David W.; Lovis, Christophe; Lundkvist, Mia S.; Mathur, Savita; Mayor, Michel; Micela, Giusi; Molinari, Emilio; Motalebi, Fatemeh; Nascimbeni, Valerio; Nava, Chantanelle; Pepe, Francesco; Phillips, David F.; Piotto, Giampaolo; Poretti, Ennio; Sasselov, Dimitar; Ségransan, Damien; Udry, Stéphane; Watson, Chris
Abstract: Measures of exoplanet bulk densities indicate that small exoplanets with radius less than 3 Earth radii (R) range from low-density sub-Neptunes containing volatile elements1 to higher-density rocky planets with Earth-like2 or iron-rich3 (Mercury-like) compositions. Such astonishing diversity in observed small exoplanet compositions may be the product of different initial conditions of the planet-formation process or different evolutionary paths that altered the planetary properties after formation4. Planet evolution may be especially affected by either photoevaporative mass loss induced by high stellar X-ray and extreme ultraviolet (XUV) flux5 or giant impacts6. Although there is some evidence for the former7,8, there are no unambiguous findings so far about the occurrence of giant impacts in an exoplanet system. Here, we characterize the two innermost planets of the compact and near- resonant system Kepler-107 (ref. 9). We show that they have nearly identical radii (about 1.5-1.6R), but the outer planet Kepler-107 c is more than twice as dense (about 12.6 g cm-3) as the innermost Kepler-107 b (about 5.3 g cm-3). In consequence, Kepler-107 c must have a larger iron core fraction than Kepler-107 b. This imbalance cannot be explained by the stellar XUV irradiation, which would conversely make the more- irradiated and less-massive planet Kepler-107 b denser than Kepler-107 c. Instead, the dissimilar densities are consistent with a giant impact event on Kepler-107 c that would have stripped off part of its silicate mantle. This hypothesis is supported by theoretical predictions from collisional mantle stripping10, which match the mass and radius of Kepler-107 c.
HARPS-N radial velocities confirm the low densities of the Kepler-9 planetsBorsato, L.Malavolta, L.Piotto, G.Buchhave, L. A.Mortier, A.Rice, K.Cameron, A. C.Coffinet, A.Sozzetti, A.Charbonneau, DavidCosentino, R.Dumusque, X.Figueira, P.Latham, David W.Lopez-Morales, MercedesMayor, M.Micela, G.Molinari, E.Pepe, F.Phillips, DavidPoretti, E.Udry, S.Watson, C.DOI: info:10.1093/mnras/stz181v. 4843233–3243
Borsato, L., Malavolta, L., Piotto, G., Buchhave, L. A., Mortier, A., Rice, K., Cameron, A. C., Coffinet, A., Sozzetti, A., Charbonneau, David, Cosentino, R., Dumusque, X., Figueira, P., Latham, David W., Lopez-Morales, Mercedes, Mayor, M., Micela, G., Molinari, E., Pepe, F., Phillips, David, Poretti, E., Udry, S., and Watson, C. 2019. "HARPS-N radial velocities confirm the low densities of the Kepler-9 planets." Monthly Notices of the Royal Astronomical Society 484:3233– 3243. https://doi.org/10.1093/mnras/stz181
ID: 151205
Type: article
Authors: Borsato, L.; Malavolta, L.; Piotto, G.; Buchhave, L. A.; Mortier, A.; Rice, K.; Cameron, A. C.; Coffinet, A.; Sozzetti, A.; Charbonneau, David; Cosentino, R.; Dumusque, X.; Figueira, P.; Latham, David W.; Lopez-Morales, Mercedes; Mayor, M.; Micela, G.; Molinari, E.; Pepe, F.; Phillips, David; Poretti, E.; Udry, S.; Watson, C.
Abstract: We investigated the discrepancy between planetary mass determinations using the transit timing variations (TTVs) and radial velocities (RVs), by analysing the multiplanet system Kepler-9. Despite being the first system characterized with TTVs, there are several discrepant solutions in the literature, with those reporting lower planetary densities being apparently in disagreement with high-precision RV observations. To resolve this, we gathered HARPS-N RVs at epochs that maximized the difference between the predicted RV curves from discrepant solutions in the literature. We also reanalysed the full Kepler data set and performed a dynamical fit, within a Bayesian framework, using the newly derived central and duration times of the transits. We compared these results with the RV data and found that our solution better describes the RV observations, despite the masses of the planets being nearly half that presented in the discovery paper. We therefore confirm that the TTV method can provide mass determinations that agree with those determined using high-precision RVs. The low densities of the planets place them in the scarcely populated region of the super-Neptunes/inflated sub-Saturns in the mass-radius diagram.
Three years of Sun-as-a-star radial-velocity observations on the approach to solar minimumCollier Cameron, A.Mortier, A.Phillips, DavidDumusque, X.Haywood, Raphaëlle D.Langellier, NicholasWatson, C. A.Cegla, H. M.Costes, J.Charbonneau, DavidCoffinet, A.Latham, David W.Lopez-Morales, MercedesMalavolta, L.Maldonado, J.Micela, G.Milbourne, TimothyMolinari, EmilioSaar, S. H.Thompson, S.Buchschacher, NicholasCecconi, M.Cosentino, R.Ghedina, A.Glenday, Alexander G.Gonzalez, M.Li, C. -HLodi, M.Lovis, C.Pepe, F.Poretti, E.Rice, K.Sasselov, DimitarSozzetti, A.Szentgyorgyi, AndrewUdry, S.Walsworth, Ronald L.DOI: info:10.1093/mnras/stz1215v. 4871082–1100
Collier Cameron, A., Mortier, A., Phillips, David, Dumusque, X., Haywood, Raphaëlle D., Langellier, Nicholas, Watson, C. A., Cegla, H. M., Costes, J., Charbonneau, David, Coffinet, A., Latham, David W., Lopez-Morales, Mercedes, Malavolta, L., Maldonado, J., Micela, G., Milbourne, Timothy, Molinari, Emilio, Saar, S. H., Thompson, S., Buchschacher, Nicholas, Cecconi, M., Cosentino, R., Ghedina, A., Glenday, Alexander G. et al. 2019. "Three years of Sun-as-a-star radial-velocity observations on the approach to solar minimum." Monthly Notices of the Royal Astronomical Society 487:1082– 1100. https://doi.org/10.1093/mnras/stz1215
ID: 154146
Type: article
Authors: Collier Cameron, A.; Mortier, A.; Phillips, David; Dumusque, X.; Haywood, Raphaëlle D.; Langellier, Nicholas; Watson, C. A.; Cegla, H. M.; Costes, J.; Charbonneau, David; Coffinet, A.; Latham, David W.; Lopez-Morales, Mercedes; Malavolta, L.; Maldonado, J.; Micela, G.; Milbourne, Timothy; Molinari, Emilio; Saar, S. H.; Thompson, S.; Buchschacher, Nicholas; Cecconi, M.; Cosentino, R.; Ghedina, A.; Glenday, Alexander G.; Gonzalez, M.; Li, C. -H; Lodi, M.; Lovis, C.; Pepe, F.; Poretti, E.; Rice, K.; Sasselov, Dimitar; Sozzetti, A.; Szentgyorgyi, Andrew; Udry, S.; Walsworth, Ronald L.
Abstract: The time-variable velocity fields of solar-type stars limit the precision of radial-velocity determinations of their planets' masses, obstructing detection of Earth twins. Since 2015 July, we have been monitoring disc-integrated sunlight in daytime using a purpose-built solar telescope and fibre feed to the HARPS-N stellar radial-velocity spectrometer. We present and analyse the solar radial-velocity measurements and cross-correlation function (CCF) parameters obtained in the first 3 yr of observation, interpreting them in the context of spatially resolved solar observations. We describe a Bayesian mixture- model approach to automated data-quality monitoring. We provide dynamical and daily differential-extinction corrections to place the radial velocities in the heliocentric reference frame, and the CCF shape parameters in the sidereal frame. We achieve a photon-noise-limited radial-velocity precision better than 0.43 m s-1 per 5-min observation. The day-to-day precision is limited by zero-point calibration uncertainty with an RMS scatter of about 0.4 m s-1. We find significant signals from granulation and solar activity. Within a day, granulation noise dominates, with an amplitude of about 0.4 m s-1 and an autocorrelation half-life of 15 min. On longer time-scales, activity dominates. Sunspot groups broaden the CCF as they cross the solar disc. Facular regions temporarily reduce the intrinsic asymmetry of the CCF. The radial-velocity increase that accompanies an active-region passage has a typical amplitude of 5 m s-1 and is correlated with the line asymmetry, but leads it by 3d. Spectral line-shape variability thus shows promise as a proxy for recovering the true radial velocity.
So close, so different: characterization of the K2-36 planetary system with HARPS-NDamasso, M.Zeng, L.Malavolta, L.Mayo, A.Sozzetti, A.Mortier, A.Buchhave, L. A.Vanderburg, AndrewLopez-Morales, MercedesBonomo, A. S.Cameron, A. C.Coffinet, A.Figueira, P.Latham, David W.Mayor, M.Molinari, E.Pepe, F.Phillips, David F.Poretti, E.Rice, K.Udry, S.Watson, C. A.DOI: info:10.1051/0004-6361/201834671v. 624A38
Damasso, M., Zeng, L., Malavolta, L., Mayo, A., Sozzetti, A., Mortier, A., Buchhave, L. A., Vanderburg, Andrew, Lopez-Morales, Mercedes, Bonomo, A. S., Cameron, A. C., Coffinet, A., Figueira, P., Latham, David W., Mayor, M., Molinari, E., Pepe, F., Phillips, David F., Poretti, E., Rice, K., Udry, S., and Watson, C. A. 2019. "So close, so different: characterization of the K2-36 planetary system with HARPS-N." Astronomy and Astrophysics 624:A38. https://doi.org/10.1051/0004-6361/201834671
ID: 155316
Type: article
Authors: Damasso, M.; Zeng, L.; Malavolta, L.; Mayo, A.; Sozzetti, A.; Mortier, A.; Buchhave, L. A.; Vanderburg, Andrew; Lopez-Morales, Mercedes; Bonomo, A. S.; Cameron, A. C.; Coffinet, A.; Figueira, P.; Latham, David W.; Mayor, M.; Molinari, E.; Pepe, F.; Phillips, David F.; Poretti, E.; Rice, K.; Udry, S.; Watson, C. A.
Abstract: Context. K2-36 is a K dwarf orbited by two small (Rb = 1.43 ± 0.08 R and Rc = 3.2 ± 0.3 R), close- in (ab = 0.022 au and ac = 0.054 au) transiting planets discovered by the Kepler/K2 space observatory. They are representatives of two distinct families of small planets (Rp ) recently emerged from the analysis of Kepler data, with likely a different structure, composition and evolutionary pathways. Aims: We revise the fundamental stellar parameters and the sizes of the planets, and provide the first measurement of their masses and bulk densities, which we use to infer their structure and composition. Methods: We observed K2-36 with the HARPS-N spectrograph over 3.5 yr, collecting 81 useful radial velocity measurements. The star is active, with evidence for increasing levels of magnetic activity during the observing time span. The radial velocity scatter is 17 m s-1 due to the stellar activity contribution, which is much larger that the semi-amplitudes of the planetary signals. We tested different methods for mitigating the stellar activity contribution to the radial velocity time variations and measuring the planet masses with good precision. Results: We find that K2-36 is likely a 1 Gyr old system, and by treating the stellar activity through a Gaussian process regression, we measured the planet masses mb = 3.9 ± 1.1 M and mc = 7.8 ± 2.3 M. The derived planet bulk densities ρb = 7.2-2.1+2.5 g cm-3 and ρc = 1.3-0.5+0.7 g cm-3 point out that K2-36 b has a rocky, Earth-like composition, and K2-36 c is a low-density sub- Neptune. Conclusions: Composed of two planets with similar orbital separations but different densities, K2-36 represents an optimal laboratory for testing the role of the atmospheric escape in driving the evolution of close-in, low-mass planets after 1 Gyr from their formation. Due to their similarities, we performed a preliminary comparative analysis between the systems K2-36 and Kepler-36, which we deem worthy of a more detailed investigation. Full Tables A.1 and A.2 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz- bin/qcat?J/A+A/624/A38
Using HARPS-N to characterize the long-period planets in the PH-2 and Kepler-103 systemsDubber, Sophie C.Mortier, AnneliesRice, KenNava, ChantanelleMalavolta, LucaGiles, HelenCoffinet, AdrienCharbonneau, DavidVanderburg, AndrewBonomo, Aldo S.Boschin, WalterBuchhave, Lars A.Cameron, Andrew CollierCosentino, RosarioDumusque, XavierGhedina, AdrianoHarutyunyan, AvetHaywood, Raphaëlle D.Latham, DavidLópez-Morales, MercedesMicela, GiusiMolinari, EmilioPepe, Francesco A.Phillips, DavidPiotto, GiampaoloPoretti, EnnioSasselov, DimitarSozzetti, AlessandroUdry, StéphaneDOI: info:10.1093/mnras/stz2856v. 4905103–5121
Dubber, Sophie C., Mortier, Annelies, Rice, Ken, Nava, Chantanelle, Malavolta, Luca, Giles, Helen, Coffinet, Adrien, Charbonneau, David, Vanderburg, Andrew, Bonomo, Aldo S., Boschin, Walter, Buchhave, Lars A., Cameron, Andrew Collier, Cosentino, Rosario, Dumusque, Xavier, Ghedina, Adriano, Harutyunyan, Avet, Haywood, Raphaëlle D., Latham, David, López-Morales, Mercedes, Micela, Giusi, Molinari, Emilio, Pepe, Francesco A., Phillips, David, Piotto, Giampaolo et al. 2019. "Using HARPS-N to characterize the long-period planets in the PH-2 and Kepler-103 systems." Monthly Notices of the Royal Astronomical Society 490:5103– 5121. https://doi.org/10.1093/mnras/stz2856
ID: 154550
Type: article
Authors: Dubber, Sophie C.; Mortier, Annelies; Rice, Ken; Nava, Chantanelle; Malavolta, Luca; Giles, Helen; Coffinet, Adrien; Charbonneau, David; Vanderburg, Andrew; Bonomo, Aldo S.; Boschin, Walter; Buchhave, Lars A.; Cameron, Andrew Collier; Cosentino, Rosario; Dumusque, Xavier; Ghedina, Adriano; Harutyunyan, Avet; Haywood, Raphaëlle D.; Latham, David; López-Morales, Mercedes; Micela, Giusi; Molinari, Emilio; Pepe, Francesco A.; Phillips, David; Piotto, Giampaolo; Poretti, Ennio; Sasselov, Dimitar; Sozzetti, Alessandro; Udry, Stéphane
Abstract: We present confirmation of the planetary nature of PH-2b, as well as the first mass estimates for the two planets in the Kepler-103 system. PH-2b and Kepler-103c are both long-period and transiting, a sparsely populated category of exoplanets. We use Kepler light-curve data to estimate a radius, and then use HARPS-N radial velocities to determine the semi-amplitude of the stellar reflex motion and, hence, the planet mass. For PH-2b we recover a 3.5σ mass estimate of M_ p = 109^{+30}_{-32} M and a radius of Rp = 9.49 ± 0.16 R. This means that PH-2b has a Saturn-like bulk density and is the only planet of this type with an orbital period P > 200 d that orbits a single star. We find that Kepler-103b has a mass of M_{p,b} = 11.7^{+4.31}_{-4.72} M and Kepler-103c has a mass of M_{p,c} = 58.5^{+11.2}_{-11.4} M. These are 2.5σ and 5σ results, respectively. With radii of R_{p,b} = 3.49^{+0.06}_{-0.05} R and R_{p,c} = 5.45^{+0.18}_{-0.17} R, these results suggest that Kepler-103b has a Neptune-like density, while Kepler-103c is one of the highest density planets with a period P &gt 100 d. By providing high-precision estimates for the masses of the long- period, intermediate-mass planets PH-2b and Kepler-103c, we increase the sample of long-period planets with known masses and radii, which will improve our understanding of the mass-radius relation across the full range of exoplanet masses and radii.
K2-291b: A Rocky Super-Earth in a 2.2 day OrbitKosiarek, Molly R.Blunt, SarahLópez-Morales, MercedesCrossfield, Ian J. M.Sinukoff, EvanPetigura, Erik A.Gonzales, Erica J.Poretti, EnnioMalavolta, LucaHoward, Andrew W.Isaacson, HowardHaywood, Raphaëlle D.Ciardi, David R.Bristow, MakennahCollier Cameron, AndrewCharbonneau, DavidDressing, Courtney D.Figueira, PedroFulton, Benjamin J.Hardee, Bronwen J.Hirsch, Lea A.Latham, David W.Mortier, AnneliesNava, ChantanelleSchlieder, Joshua E.Vanderburg, AndrewWeiss, LaurenBonomo, Aldo S.Bouchy, FrançoisBuchhave, Lars A.Coffinet, AdrienDamasso, MarioDumusque, XavierLovis, ChristopheMayor, MichelMicela, GiusiMolinari, EmilioPepe, FrancescoPhillips, DavidPiotto, GiampaoloRice, KenSasselov, DimitarSégransan, DamienSozzetti, AlessandroUdry, StéphaneWatson, ChrisDOI: info:10.3847/1538-3881/aafe83v. 157116
Kosiarek, Molly R., Blunt, Sarah, López-Morales, Mercedes, Crossfield, Ian J. M., Sinukoff, Evan, Petigura, Erik A., Gonzales, Erica J., Poretti, Ennio, Malavolta, Luca, Howard, Andrew W., Isaacson, Howard, Haywood, Raphaëlle D., Ciardi, David R., Bristow, Makennah, Collier Cameron, Andrew, Charbonneau, David, Dressing, Courtney D., Figueira, Pedro, Fulton, Benjamin J., Hardee, Bronwen J., Hirsch, Lea A., Latham, David W., Mortier, Annelies, Nava, Chantanelle, Schlieder, Joshua E. et al. 2019. "K2-291b: A Rocky Super-Earth in a 2.2 day Orbit." The Astronomical Journal 157:116. https://doi.org/10.3847/1538-3881/aafe83
ID: 150911
Type: article
Authors: Kosiarek, Molly R.; Blunt, Sarah; López-Morales, Mercedes; Crossfield, Ian J. M.; Sinukoff, Evan; Petigura, Erik A.; Gonzales, Erica J.; Poretti, Ennio; Malavolta, Luca; Howard, Andrew W.; Isaacson, Howard; Haywood, Raphaëlle D.; Ciardi, David R.; Bristow, Makennah; Collier Cameron, Andrew; Charbonneau, David; Dressing, Courtney D.; Figueira, Pedro; Fulton, Benjamin J.; Hardee, Bronwen J.; Hirsch, Lea A.; Latham, David W.; Mortier, Annelies; Nava, Chantanelle; Schlieder, Joshua E.; Vanderburg, Andrew; Weiss, Lauren; Bonomo, Aldo S.; Bouchy, François; Buchhave, Lars A.; Coffinet, Adrien; Damasso, Mario; Dumusque, Xavier; Lovis, Christophe; Mayor, Michel; Micela, Giusi; Molinari, Emilio; Pepe, Francesco; Phillips, David; Piotto, Giampaolo; Rice, Ken; Sasselov, Dimitar; Ségransan, Damien; Sozzetti, Alessandro; Udry, Stéphane; Watson, Chris
Abstract: K2-291 is a solar-type star with a radius of R * = 0.899 ± 0.034 R and mass of M* = 0.934 ± 0.038 M . From the K2 C13 data, we found one super-Earth planet (R p = {1.589}-0.072+0.095 R ) transiting this star on a short period orbit (P = {2.225177}-6.8{{e}{--}5}+6.6{{e}{--}5} days). We followed this system up with adaptive-optic imaging and spectroscopy to derive stellar parameters, search for stellar companions, and determine a planet mass. From our 75 radial velocity measurements using High Resolution Echelle Spectrometer on Keck I and High Accuracy Radial velocity Planet Searcher in the northern hemisphere on Telescopio Nazionale Galileo, we constrained the mass of K2-291 b to M p = 6.49 ± 1.16 M . We found it necessary to model correlated stellar activity radial velocity signals with a Gaussian process (GP) in order to more accurately model the effect of stellar noise on our data; the addition of the GP also improved the precision of this mass measurement. With a bulk density of ρ = 8.84{}-2.03+2.50 g cm-3, the planet is consistent with an Earth-like rock/iron composition and no substantial gaseous envelope. Such an envelope, if it existed in the past, was likely eroded away by photoevaporation during the first billion years of the star’s lifetime.
Temporal evolution and correlations of optical activity indicators measured in Sun-as-a-star observationsMaldonado, J.Phillips, David F.Dumusque, X.Collier Cameron, A.Haywood, Raphaëlle D.Lanza, A. F.Micela, G.Mortier, A.Saar, Steven H.Sozzetti, A.Rice, K.Milbourne, TimothyCecconi, M.Cegla, H. M.Cosentino, R.Costes, J.Ghedina, A.Gonzalez, M.Guerra, J.Hernández, N.Li, C. -HLodi, M.Malavolta, L.Molinari, E.Pepe, F.Piotto, G.Poretti, E.Sasselov, DimitarSan Juan, J.Thompson, S.Udry, S.Watson, C.DOI: info:10.1051/0004-6361/201935233v. 627A118
Maldonado, J., Phillips, David F., Dumusque, X., Collier Cameron, A., Haywood, Raphaëlle D., Lanza, A. F., Micela, G., Mortier, A., Saar, Steven H., Sozzetti, A., Rice, K., Milbourne, Timothy, Cecconi, M., Cegla, H. M., Cosentino, R., Costes, J., Ghedina, A., Gonzalez, M., Guerra, J., Hernández, N., Li, C. -H, Lodi, M., Malavolta, L., Molinari, E., Pepe, F. et al. 2019. "Temporal evolution and correlations of optical activity indicators measured in Sun-as-a-star observations." Astronomy and Astrophysics 627:A118. https://doi.org/10.1051/0004-6361/201935233
ID: 154167
Type: article
Authors: Maldonado, J.; Phillips, David F.; Dumusque, X.; Collier Cameron, A.; Haywood, Raphaëlle D.; Lanza, A. F.; Micela, G.; Mortier, A.; Saar, Steven H.; Sozzetti, A.; Rice, K.; Milbourne, Timothy; Cecconi, M.; Cegla, H. M.; Cosentino, R.; Costes, J.; Ghedina, A.; Gonzalez, M.; Guerra, J.; Hernández, N.; Li, C. -H; Lodi, M.; Malavolta, L.; Molinari, E.; Pepe, F.; Piotto, G.; Poretti, E.; Sasselov, Dimitar; San Juan, J.; Thompson, S.; Udry, S.; Watson, C.
Abstract: Context. Understanding stellar activity in solar-type stars is crucial for the physics of stellar atmospheres as well as for ongoing exoplanet programmes. Aims: We aim to test how well we understand stellar activity using our own star, the Sun, as a test case. Methods: We performed a detailed study of the main optical activity indicators (Ca II H & K, Balmer lines, Na I D1 D2, and He I D3) measured for the Sun using the data provided by the HARPS-N solar-telescope feed at the Telescopio Nazionale Galileo. We made use of periodogram analyses to study solar rotation, and we used the pool variance technique to study the temporal evolution of active regions. The correlations between the different activity indicators as well as the correlations between activity indexes and the derived parameters from the cross-correlation technique are analysed. We also study the temporal evolution of these correlations and their possible relationship with indicators of inhomogeneities in the solar photosphere like sunspot number or radio flux values. Results: The value of the solar rotation period is found in all the activity indicators, with the only exception being Hδ. The derived values vary from 26.29 days (Hγ line) to 31.23 days (He I). From an analysis of sliding periodograms we find that in most of the activity indicators the spectral power is split into several "bands" of periods around 26 and 30 days. They might be explained by the migration of active regions between the equator and a latitude of ̃30°, spot evolution, or a combination of both effects. A typical lifetime of active regions of approximately ten rotation periods is inferred from the pooled variance diagrams, which is in agreement with previous works. We find that Hα, Hβ, Hγ, H∊, and He I show a significant correlation with the S index. Significant correlations between the contrast, bisector span, and the heliocentric radial velocity with the activity indexes are also found. We show that the full width at half maximum, the bisector, and the disc-integrated magnetic field correlate with the radial velocity variations. The correlation ofthe S index and Hα changes with time, increasing with larger sun spot numbers and solar irradiance. A similar tendency with the S index and radial velocity correlation is also present in the data. Conclusions: Our results are consistent with a scenario in which higher activity favours the correlation between the S index and the Hα activity indicators and between the S index and radial velocity variations. Table A.1 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/627/A118
An 11 Earth-mass, Long-period Sub-Neptune Orbiting a Sun-like StarMayo, Andrew W.Rajpaul, Vinesh M.Buchhave, Lars A.Dressing, Courtney D.Mortier, AnneliesZeng, LiFortenbach, Charles D.Aigrain, SuzanneBonomo, Aldo S.Collier Cameron, AndrewCharbonneau, DavidCoffinet, AdrienCosentino, RosarioDamasso, MarioDumusque, XavierMartinez Fiorenzano, A. F.Haywood, Raphaëlle D.Latham, David W.López-Morales, MercedesMalavolta, LucaMicela, GiusiMolinari, EmilioPearce, LoganPepe, FrancescoPhillips, DavidPiotto, GiampaoloPoretti, EnnioRice, KenSozzetti, AlessandroUdry, StephaneDOI: info:10.3847/1538-3881/ab3e2fv. 158165
Mayo, Andrew W., Rajpaul, Vinesh M., Buchhave, Lars A., Dressing, Courtney D., Mortier, Annelies, Zeng, Li, Fortenbach, Charles D., Aigrain, Suzanne, Bonomo, Aldo S., Collier Cameron, Andrew, Charbonneau, David, Coffinet, Adrien, Cosentino, Rosario, Damasso, Mario, Dumusque, Xavier, Martinez Fiorenzano, A. F., Haywood, Raphaëlle D., Latham, David W., López-Morales, Mercedes, Malavolta, Luca, Micela, Giusi, Molinari, Emilio, Pearce, Logan, Pepe, Francesco, Phillips, David et al. 2019. "An 11 Earth-mass, Long-period Sub-Neptune Orbiting a Sun-like Star." The Astronomical Journal 158:165. https://doi.org/10.3847/1538-3881/ab3e2f
ID: 154640
Type: article
Authors: Mayo, Andrew W.; Rajpaul, Vinesh M.; Buchhave, Lars A.; Dressing, Courtney D.; Mortier, Annelies; Zeng, Li; Fortenbach, Charles D.; Aigrain, Suzanne; Bonomo, Aldo S.; Collier Cameron, Andrew; Charbonneau, David; Coffinet, Adrien; Cosentino, Rosario; Damasso, Mario; Dumusque, Xavier; Martinez Fiorenzano, A. F.; Haywood, Raphaëlle D.; Latham, David W.; López-Morales, Mercedes; Malavolta, Luca; Micela, Giusi; Molinari, Emilio; Pearce, Logan; Pepe, Francesco; Phillips, David; Piotto, Giampaolo; Poretti, Ennio; Rice, Ken; Sozzetti, Alessandro; Udry, Stephane
Abstract: Although several thousands of exoplanets have now been detected and characterized, observational biases have led to a paucity of long- period, low-mass exoplanets with measured masses and a corresponding lag in our understanding of such planets. In this paper we report the mass estimation and characterization of the long-period exoplanet Kepler- 538b. This planet orbits a Sun-like star (V = 11.27) with {M}* ={0.892}-0.035+0.051 M and {R}* ={0.8717}-0.0061+0.0064 R . Kepler-538b is a {2.215}-0.034+0.040 R sub-Neptune with a period of P = 81.73778 ± 0.00013 days. It is the only known planet in the system. We collected radial velocity (RV) observations with the High Resolution Echelle Spectrometer (HIRES) on Keck I and High Accuracy Radial velocity Planet Searcher in North hemisphere (HARPS-N) on the Telescopio Nazionale Galileo (TNG). We characterized stellar activity by a Gaussian process with a quasi- periodic kernel applied to our RV and cross-correlation function FWHM observations. By simultaneously modeling Kepler photometry, RV, and FWHM observations, we found a semi-amplitude of K={1.68}-0.38+0.39 m s-1 and a planet mass of {M}p={10.6}-2.4+2.5 M . Kepler-538b is the smallest planet beyond P = 50 days with an RV mass measurement. The planet likely consists of a significant fraction of ices (dominated by water ice), in addition to rocks/metals, and a small amount of gas. Sophisticated modeling techniques such as those used in this paper, combined with future spectrographs with ultra high-precision and stability will be vital for yielding more mass measurements in this poorly understood exoplanet regime. This in turn will improve our understanding of the relationship between planet composition and insolation flux and how the rocky to gaseous transition depends on planetary equilibrium temperature.
HARPS-N Solar RVs Are Dominated by Large, Bright Magnetic RegionsMilbourne, Timothy W.Haywood, Raphaëlle D.Phillips, David F.Saar, Steve H.Cegla, H. M.Cameron, A. C.Costes, J.Dumusque, X.Langellier, NicholasLatham, David W.Maldonado, J.Malavolta, L.Mortier, A.Palumbo, Michael L.,IIIThompson, S.Watson, C. A.Bouchy, F.Buchschacher, N.Cecconi, M.Charbonneau, DavidCosentino, R.Ghedina, A.Glenday, Alexander G.Gonzalez, M.Li, C. -HLodi, M.López-Morales, MercedesLovis, C.Mayor, M.Micela, G.Molinari, E.Pepe, F.Piotto, G.Rice, K.Sasselov, DimitarSégransan, D.Sozzetti, A.Szentgyorgyi, AndrewUdry, S.Walsworth, Ronald L.DOI: info:10.3847/1538-4357/ab064av. 874107
Milbourne, Timothy W., Haywood, Raphaëlle D., Phillips, David F., Saar, Steve H., Cegla, H. M., Cameron, A. C., Costes, J., Dumusque, X., Langellier, Nicholas, Latham, David W., Maldonado, J., Malavolta, L., Mortier, A., Palumbo, Michael L.,III, Thompson, S., Watson, C. A., Bouchy, F., Buchschacher, N., Cecconi, M., Charbonneau, David, Cosentino, R., Ghedina, A., Glenday, Alexander G., Gonzalez, M., Li, C. -H et al. 2019. "HARPS-N Solar RVs Are Dominated by Large, Bright Magnetic Regions." The Astrophysical Journal 874:107. https://doi.org/10.3847/1538-4357/ab064a
ID: 155443
Type: article
Authors: Milbourne, Timothy W.; Haywood, Raphaëlle D.; Phillips, David F.; Saar, Steve H.; Cegla, H. M.; Cameron, A. C.; Costes, J.; Dumusque, X.; Langellier, Nicholas; Latham, David W.; Maldonado, J.; Malavolta, L.; Mortier, A.; Palumbo, Michael L.,III; Thompson, S.; Watson, C. A.; Bouchy, F.; Buchschacher, N.; Cecconi, M.; Charbonneau, David; Cosentino, R.; Ghedina, A.; Glenday, Alexander G.; Gonzalez, M.; Li, C. -H; Lodi, M.; López-Morales, Mercedes; Lovis, C.; Mayor, M.; Micela, G.; Molinari, E.; Pepe, F.; Piotto, G.; Rice, K.; Sasselov, Dimitar; Ségransan, D.; Sozzetti, A.; Szentgyorgyi, Andrew; Udry, S.; Walsworth, Ronald L.
Abstract: State-of-the-art radial-velocity (RV) exoplanet searches are currently limited by RV signals arising from stellar magnetic activity. We analyze solar observations acquired over a 3 yr period during the decline of Carrington Cycle 24 to test models of RV variation of Sun-like stars. A purpose-built solar telescope at the High Accuracy Radial-velocity Planet Searcher for the Northern hemisphere (HARPS-N) provides disk- integrated solar spectra, from which we extract RVs and {log}{R}HK}{\prime }. The Solar Dynamics Observatory (SDO) provides disk-resolved images of magnetic activity. The Solar Radiation and Climate Experiment (SORCE) provides near- continuous solar photometry, analogous to a Kepler light curve. We verify that the SORCE photometry and HARPS-N {log}{R}HK}{\prime } correlate strongly with the SDO-derived magnetic filling factor, while the HARPS-N RV variations do not. To explain this discrepancy, we test existing models of RV variations. We estimate the contributions of the suppression of convective blueshift and the rotational imbalance due to brightness inhomogeneities to the observed HARPS-N RVs. We investigate the time variation of these contributions over several rotation periods, and how these contributions depend on the area of active regions. We find that magnetic active regions smaller than 60 Mm2 do not significantly suppress convective blueshift. Our area-dependent model reduces the amplitude of activity-induced RV variations by a factor of two. The present study highlights the need to identify a proxy that correlates specifically with large, bright magnetic regions on the surfaces of exoplanet-hosting stars.
Probing Dark Matter Using Precision Measurements of Stellar AccelerationsRavi, AakashLangellier, NicholasPhillips, David F.Buschmann, MalteSafdi, Benjamin R.Walsworth, Ronald L.DOI: info:10.1103/PhysRevLett.123.091101v. 123091101
Ravi, Aakash, Langellier, Nicholas, Phillips, David F., Buschmann, Malte, Safdi, Benjamin R., and Walsworth, Ronald L. 2019. "Probing Dark Matter Using Precision Measurements of Stellar Accelerations." Physical Review Letters 123:091101. https://doi.org/10.1103/PhysRevLett.123.091101
ID: 154254
Type: article
Authors: Ravi, Aakash; Langellier, Nicholas; Phillips, David F.; Buschmann, Malte; Safdi, Benjamin R.; Walsworth, Ronald L.
Abstract: Dark matter comprises the bulk of the matter in the Universe, but its particle nature and cosmological origin remain mysterious. Knowledge of the dark matter density distribution in the Milky Way Galaxy is crucial both to our understanding of the standard cosmological model and for grounding direct and indirect searches for the particles comprising dark matter. Current measurements of Galactic dark matter content rely on model assumptions to infer the forces acting upon stars from the distribution of observed velocities. Here, we propose to apply the precision radial velocity method, optimized in recent years for exoplanet astronomy, to measure the change in the velocity of stars over time, thereby providing a direct probe of the local gravitational potential in the Galaxy. Using numerical simulations, we develop a realistic strategy to observe the differential accelerations of stars in our Galactic neighborhood with next-generation telescopes, at the level of 10-8 cm /s2 . Our simulations show that detecting accelerations at this level with an ensemble of 103 stars requires the effect of stellar noise on radial velocity measurements to be reduced to <10 cm /s . The measured stellar accelerations may then be used to extract the local dark matter density and morphological parameters of the density profile.
Masses and radii for the three super-Earths orbiting GJ 9827, and implications for the composition of small exoplanetsRice, K.Malavolta, L.Mayo, A.Mortier, A.Buchhave, L. A.Affer, L.Vanderburg, AndrewLopez-Morales, MercedesPoretti, E.Zeng, L.Cameron, A. C.Damasso, M.Coffinet, A.Latham, David W.Bonomo, A. S.Bouchy, F.Charbonneau, DavidDumusque, X.Figueira, P.Martinez Fiorenzano, A. F.Haywood, Raphaëlle D.Johnson, J. AsherLopez, E.Lovis, C.Mayor, M.Micela, G.Molinari, E.Nascimbeni, V.Nava, ChantanellePepe, F.Phillips, David F.Piotto, G.Sasselov, DimitarSégransan, D.Sozzetti, A.Udry, S.Watson, C.DOI: info:10.1093/mnras/stz130v. 4843731–3745
Rice, K., Malavolta, L., Mayo, A., Mortier, A., Buchhave, L. A., Affer, L., Vanderburg, Andrew, Lopez-Morales, Mercedes, Poretti, E., Zeng, L., Cameron, A. C., Damasso, M., Coffinet, A., Latham, David W., Bonomo, A. S., Bouchy, F., Charbonneau, David, Dumusque, X., Figueira, P., Martinez Fiorenzano, A. F., Haywood, Raphaëlle D., Johnson, J. Asher, Lopez, E., Lovis, C., Mayor, M. et al. 2019. "Masses and radii for the three super-Earths orbiting GJ 9827, and implications for the composition of small exoplanets." Monthly Notices of the Royal Astronomical Society 484:3731– 3745. https://doi.org/10.1093/mnras/stz130
ID: 151203
Type: article
Authors: Rice, K.; Malavolta, L.; Mayo, A.; Mortier, A.; Buchhave, L. A.; Affer, L.; Vanderburg, Andrew; Lopez-Morales, Mercedes; Poretti, E.; Zeng, L.; Cameron, A. C.; Damasso, M.; Coffinet, A.; Latham, David W.; Bonomo, A. S.; Bouchy, F.; Charbonneau, David; Dumusque, X.; Figueira, P.; Martinez Fiorenzano, A. F.; Haywood, Raphaëlle D.; Johnson, J. Asher; Lopez, E.; Lovis, C.; Mayor, M.; Micela, G.; Molinari, E.; Nascimbeni, V.; Nava, Chantanelle; Pepe, F.; Phillips, David F.; Piotto, G.; Sasselov, Dimitar; Ségransan, D.; Sozzetti, A.; Udry, S.; Watson, C.
Abstract: Super-Earths belong to a class of planet not found in the Solar system, but which appear common in the Galaxy. Given that some super-Earths are rocky, while others retain substantial atmospheres, their study can provide clues as to the formation of both rocky and gaseous planets, and - in particular - they can help to constrain the role of photoevaporation in sculpting the exoplanet population. GJ 9827 is a system already known to host three super-Earths with orbital periods of 1.2, 3.6, and 6.2 d. Here, we use new HARPS-N radial velocity measurements, together with previously published radial velocities, to better constrain the properties of the GJ 9827 planets. Our analysis cannot place a strong constraint on the mass of GJ 9827 c, but does indicate that GJ 9827 b is rocky with a composition that is probably similar to that of the Earth, while GJ 9827 d almost certainly retains a volatile envelope. Therefore, GJ 9827 hosts planets on either side of the radius gap that appears to divide super-Earths into pre-dominantly rocky ones that have radii below ˜1.5R, and ones that still retain a substantial atmosphere and/or volatile components, and have radii above ˜2R. That the less heavily irradiated of the three planets still retains an atmosphere, may indicate that photoevaporation has played a key role in the evolution of the planets in this system.
Eyes on K2-3: A system of three likely sub-Neptunes characterized with HARPS-N and HARPSDamasso, M.Bonomo, A. S.Astudillo-Defru, N.Bonfils, X.Malavolta, L.Sozzetti, A.Lopez, E.Zeng, L.Haywood, R. D.Irwin, J. M.Mortier, A.Vanderburg, AndrewMaldonado, J.Lanza, A. F.Affer, L.Almenara, J. -MBenatti, S.Biazzo, K.Bignamini, A.Borsa, F.Bouchy, F.Buchhave, L. A.Cameron, A. C.Carleo, I.Charbonneau, D.Claudi, R.Cosentino, R.Covino, E.Delfosse, X.Desidera, S.Di Fabrizio, L.Dressing, C.Esposito, M.Fares, R.Figueira, P.Fiorenzano, A. F. M.Forveille, T.Giacobbe, P.González-Álvarez, E.Gratton, R.Harutyunyan, A.Johnson, J. AsherLatham, D. W.Leto, G.Lopez-Morales, M.Lovis, C.Maggio, A.Mancini, L.Masiero, S.Mayor, M.Micela, G.Molinari, E.Motalebi, F.Murgas, F.Nascimbeni, V.Pagano, I.Pepe, F.Phillips, D. F.Piotto, G.Poretti, E.Rainer, M.Rice, K.Santos, N. C.Sasselov, D.Scandariato, G.Ségransan, D.Smareglia, R.Udry, S.Watson, C.Wünsche, A.DOI: info:10.1051/0004-6361/201732459v. 615A69
Damasso, M., Bonomo, A. S., Astudillo-Defru, N., Bonfils, X., Malavolta, L., Sozzetti, A., Lopez, E., Zeng, L., Haywood, R. D., Irwin, J. M., Mortier, A., Vanderburg, Andrew, Maldonado, J., Lanza, A. F., Affer, L., Almenara, J. -M, Benatti, S., Biazzo, K., Bignamini, A., Borsa, F., Bouchy, F., Buchhave, L. A., Cameron, A. C., Carleo, I., Charbonneau, D. et al. 2018. "Eyes on K2-3: A system of three likely sub-Neptunes characterized with HARPS-N and HARPS." Astronomy and Astrophysics 615:A69. https://doi.org/10.1051/0004-6361/201732459
ID: 147925
Type: article
Authors: Damasso, M.; Bonomo, A. S.; Astudillo-Defru, N.; Bonfils, X.; Malavolta, L.; Sozzetti, A.; Lopez, E.; Zeng, L.; Haywood, R. D.; Irwin, J. M.; Mortier, A.; Vanderburg, Andrew; Maldonado, J.; Lanza, A. F.; Affer, L.; Almenara, J. -M; Benatti, S.; Biazzo, K.; Bignamini, A.; Borsa, F.; Bouchy, F.; Buchhave, L. A.; Cameron, A. C.; Carleo, I.; Charbonneau, D.; Claudi, R.; Cosentino, R.; Covino, E.; Delfosse, X.; Desidera, S.; Di Fabrizio, L.; Dressing, C.; Esposito, M.; Fares, R.; Figueira, P.; Fiorenzano, A. F. M.; Forveille, T.; Giacobbe, P.; González-Álvarez, E.; Gratton, R.; Harutyunyan, A.; Johnson, J. Asher; Latham, D. W.; Leto, G.; Lopez-Morales, M.; Lovis, C.; Maggio, A.; Mancini, L.; Masiero, S.; Mayor, M.; Micela, G.; Molinari, E.; Motalebi, F.; Murgas, F.; Nascimbeni, V.; Pagano, I.; Pepe, F.; Phillips, D. F.; Piotto, G.; Poretti, E.; Rainer, M.; Rice, K.; Santos, N. C.; Sasselov, D.; Scandariato, G.; Ségransan, D.; Smareglia, R.; Udry, S.; Watson, C.; Wünsche, A.
Abstract: Context. M-dwarf stars are promising targets for identifying and characterizing potentially habitable planets. K2-3 is a nearby (45 pc), early-type M dwarf hosting three small transiting planets, the outermost of which orbits close to the inner edge of the stellar (optimistic) habitable zone. The K2-3 system is well suited for follow-up characterization studies aimed at determining accurate masses and bulk densities of the three planets.
Aims: Using a total of 329 radial velocity measurements collected over 2.5 years with the HARPS-N and HARPS spectrographs and a proper treatment of the stellar activity signal, we aim to improve measurements of the masses and bulk densities of the K2-3 planets. We use our results to investigate the physical structure of the planets.
Methods: We analysed radial velocity time series extracted with two independent pipelines using Gaussian process regression. We adopted a quasi-periodic kernel to model the stellar magnetic activity jointly with the planetary signals. We used Monte Carlo simulations to investigate the robustness of our mass measurements of K2-3 c and K2-3 d, and to explore how additional high-cadence radial velocity observations might improve these values.
Results: Even though the stellar activity component is the strongest signal present in the radial velocity time series, we are able to derive masses for both planet b (Mb = 6.6 ± 1.1 M&oplus;) and planet c (Mc = 3.1-1.2+1.3 M&oplus;). The Doppler signal from K2-3 d remains undetected, likely because of its low amplitude compared to the radial velocity signal induced by the stellar activity. The closeness of the orbital period of K2-3 d to the stellar rotation period could also make the detection of the planetary signal complicated. Based on our ability to recover injected signals in simulated data, we tentatively estimate the mass of K2-3 d to be Md = 2.7-0.8+1.2 M&oplus; M&oplus;. These mass measurements imply that the bulk densities and therefore the interior structures of the three planets may be similar. In particular, the planets may either have small H/He envelopes (=50% of their total mass, on top of rocky cores. Placing further constraints on the bulk densities of K2-3 c and d is difficult; in particular, we would not have been able to detect the Doppler signal of K2-3 d even by adopting a semester of intense, high-cadence radial velocity observations with HARPS-N and HARPS. Tables A.1-A.5 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/615/A69
An Accurate Mass Determination for Kepler-1655b, a Moderately Irradiated World with a Significant Volatile EnvelopeHaywood, Raphaëlle D.Vanderburg, AndrewMortier, AnneliesGiles, Helen A. C.López-Morales, MercedesLopez, Eric D.Malavolta, LucaCharbonneau, DavidCollier Cameron, AndrewCoughlin, Jeffrey L.Dressing, Courtney D.Nava, ChantanelleLatham, David W.Dumusque, XavierLovis, ChristopheMolinari, EmilioPepe, FrancescoSozzetti, AlessandroUdry, StéphaneBouchy, FrançoisJohnson, John A.Mayor, MichelMicela, GiusiPhillips, DavidPiotto, GiampaoloRice, KenSasselov, DimitarSégransan, DamienWatson, ChrisAffer, LauraBonomo, Aldo S.Buchhave, Lars A.Ciardi, David R.Fiorenzano, Aldo F.Harutyunyan, AvetDOI: info:10.3847/1538-3881/aab8f3v. 155203
Haywood, Raphaëlle D., Vanderburg, Andrew, Mortier, Annelies, Giles, Helen A. C., López-Morales, Mercedes, Lopez, Eric D., Malavolta, Luca, Charbonneau, David, Collier Cameron, Andrew, Coughlin, Jeffrey L., Dressing, Courtney D., Nava, Chantanelle, Latham, David W., Dumusque, Xavier, Lovis, Christophe, Molinari, Emilio, Pepe, Francesco, Sozzetti, Alessandro, Udry, Stéphane, Bouchy, François, Johnson, John A., Mayor, Michel, Micela, Giusi, Phillips, David, Piotto, Giampaolo et al. 2018. "An Accurate Mass Determination for Kepler-1655b, a Moderately Irradiated World with a Significant Volatile Envelope." The Astronomical Journal 155:203. https://doi.org/10.3847/1538-3881/aab8f3
ID: 147420
Type: article
Authors: Haywood, Raphaëlle D.; Vanderburg, Andrew; Mortier, Annelies; Giles, Helen A. C.; López-Morales, Mercedes; Lopez, Eric D.; Malavolta, Luca; Charbonneau, David; Collier Cameron, Andrew; Coughlin, Jeffrey L.; Dressing, Courtney D.; Nava, Chantanelle; Latham, David W.; Dumusque, Xavier; Lovis, Christophe; Molinari, Emilio; Pepe, Francesco; Sozzetti, Alessandro; Udry, Stéphane; Bouchy, François; Johnson, John A.; Mayor, Michel; Micela, Giusi; Phillips, David; Piotto, Giampaolo; Rice, Ken; Sasselov, Dimitar; Ségransan, Damien; Watson, Chris; Affer, Laura; Bonomo, Aldo S.; Buchhave, Lars A.; Ciardi, David R.; Fiorenzano, Aldo F.; Harutyunyan, Avet
Abstract: We present the confirmation of a small, moderately irradiated (F = 155 ± 7 F &oplus;) Neptune with a substantial gas envelope in a P = 11.8728787 ± 0.0000085 day orbit about a quiet, Sun-like G0V star Kepler-1655. Based on our analysis of the Kepler light curve, we determined Kepler-1655b's radius to be 2.213 ± 0.082 R &oplus;. We acquired 95 high-resolution spectra with Telescopio Nazionale Galileo/HARPS-N, enabling us to characterize the host star and determine an accurate mass for Kepler-1655b of 5.0{+/- }2.83.1 {M}\oplus via Gaussian-process regression. Our mass determination excludes an Earth-like composition with 98% confidence. Kepler-1655b falls on the upper edge of the evaporation valley, in the relatively sparsely occupied transition region between rocky and gas-rich planets. It is therefore part of a population of planets that we should actively seek to characterize further.