Publication Search Results

ID: 154595
Type: article
Authors: Rodriguez, Joseph E.; Eastman, Jason D.; Zhou, George; Quinn, Samuel N.; Beatty, Thomas G.; Penev, Kaloyan; Johnson, Marshall C.; Cargile, Phillip A.; Latham, David W.; Bieryla, Allyson; Collins, Karen A.; Dressing, Courtney D.; Ciardi, David R.; Relles, Howard M.; Murawski, Gabriel; Nishiumi, Taku; Yonehara, Atsunori; Ishimaru, Ryo; Yoshida, Fumi; Gregorio, Joao; Lund, Michael B.; Stevens, Daniel J.; Stassun, Keivan G.; Gaudi, B. Scott; Colón, Knicole D.; Pepper, Joshua; Narita, Norio; Awiphan, Supachai; Chuanraksasat, Pongpichit; Benni, Paul; Zambelli, Roberto; Garrison, Lehman H.; Wilson, Maurice L.; Cornachione, Matthew A.; Wang, Sharon X.; Labadie-Bartz, Jonathan; Rodríguez, Romy; Siverd, Robert J.; Yao, Xinyu; Bayliss, Daniel; Berlind, Perry; Calkins, Michael L.; Christiansen, Jessie L.; Cohen, David H.; Conti, Dennis M.; Curtis, Ivan A.; DePoy, D. L.; Esquerdo, Gilbert A.; Evans, Phil; Feliz, Dax; Fulton, Benjamin J.; Holoien, Thomas W. -S; James, David J.; Jayasinghe, Tharindu; Jang-Condell, Hannah; Jensen, Eric L. N.; Johnson, John A.; Joner, Michael D.; Khakpash, Somayeh; Kielkopf, John F.; Kuhn, Rudolf B.; Manner, Mark; Marshall, Jennifer L.; McLeod, Kim K.; McCrady, Nate; Oberst, Thomas E.; Oelkers, Ryan J.; Penny, Matthew T.; Reed, Phillip A.; Sliski, David H.; Shappee, B. J.; Stephens, Denise C.; Stockdale, Chris; Tan, Thiam-Guan; Trueblood, Mark; Trueblood, Pat; Villanueva, Steven, Jr.; Wittenmyer, Robert A.; Wright, Jason T.
Abstract: We present the discovery of KELT-24 b, a massive hot Jupiter orbiting a bright (V = 8.3 mag, K = 7.2 mag) young F-star with a period of 5.6 days. The host star, KELT-24 (HD 93148), has a T _eff = {6509}_-49⁺⁵⁰ K, a mass of M _* = {1.460}_-0.059^+0.055 M _☉, a radius of R _* = 1.506 ± 0.022 R _☉, and an age of {0.78}_-0.42^+0.61 Gyr. Its planetary companion (KELT-24 b) has a radius of R _P = 1.272 ± 0.021 R _J and a mass of M _P = {5.18}_-0.22^+0.21 M _J, and from Doppler tomographic observations, we find that the planet's orbit is well- aligned to its host star's projected spin axis (λ ={2.6}_-3.6^+5.1). The young age estimated for KELT-24 suggests that it only recently started to evolve from the zero- age main sequence. KELT-24 is the brightest star known to host a transiting giant planet with a period between 5 and 10 days. Although the circularization timescale is much longer than the age of the system, we do not detect a large eccentricity or significant misalignment that is expected from dynamical migration. The brightness of its host star and its moderate surface gravity make KELT-24b an intriguing target for detailed atmospheric characterization through spectroscopic emission measurements since it would bridge the current literature results that have primarily focused on lower mass hot Jupiters and a few brown dwarfs.

ID: 154440
Type: article
Authors: Wilson, Maurice L.; Eastman, Jason D.; Cornachione, Matthew A.; Wang, Sharon X.; Johnson, Samson A.; Sliski, David H.; Schap, William J.,III; Morton, Timothy D.; Johnson, John Asher; McCrady, Nate; Wright, Jason T.; Wittenmyer, Robert A.; Plavchan, Peter; Blake, Cullen H.; Swift, Jonathan J.; Bottom, Michael; Baker, Ashley D.; Barnes, Stuart I.; Berlind, Perry; Blackhurst, Eric; Beatty, Thomas G.; Bolton, Adam S.; Cale, Bryson; Calkins, Michael L.; Colón, Ana; de Vera, Jon; Esquerdo, Gilbert; Falco, Emilio E.; Fortin, Pascal; Garcia-Mejia, Juliana; Geneser, Claire; Gibson, Steven R.; Grell, Gabriel; Groner, Ted; Halverson, Samuel; Hamlin, John; Henderson, M.; Horner, J.; Houghton, Audrey; Janssens, Stefaan; Jonas, Graeme; Jones, Damien; Kirby, Annie; Lawrence, George; Luebbers, Julien Andrew; Muirhead, Philip S.; Myles, Justin; Nava, Chantanelle; Rivera-García, Kevin O.; Reed, Tony; Relles, Howard M.; Riddle, Reed; Robinson, Connor; Chaput de Saintonge, Forest; Sergi, Anthony
Abstract: The MINiature Exoplanet Radial Velocity Array (MINERVA) is a dedicated observatory of four 0.7 m robotic telescopes fiber-fed to a KiwiSpec spectrograph. The MINERVA mission is to discover super-Earths in the habitable zones of nearby stars. This can be accomplished with MINERVA's unique combination of high precision and high cadence over long time periods. In this work, we detail changes to the MINERVA facility that have occurred since our previous paper. We then describe MINERVA's robotic control software, the process by which we perform 1D spectral extraction, and our forward modeling Doppler pipeline. In the process of improving our forward modeling procedure, we found that our spectrograph's intrinsic instrumental profile is stable for at least nine months. Because of that, we characterized our instrumental profile with a time-independent, cubic spline function based on the profile in the cross dispersion direction, with which we achieved a radial velocity precision similar to using a conventional "sum-of-Gaussians" instrumental profile: 1.8 m s^-1 over 1.5 months on the RV standard star HD 122064. Therefore, we conclude that the instrumental profile need not be perfectly accurate as long as it is stable. In addition, we observed 51 Peg and our results are consistent with the literature, confirming our spectrograph and Doppler pipeline are producing accurate and precise radial velocities.

ID: 144824
Type: article
Authors: Lund, Michael B.; Rodriguez, Joseph E.; Zhou, George; Gaudi, B. Scott; Stassun, Keivan G.; Johnson, Marshall C.; Bieryla, Allyson; Oelkers, Ryan J.; Stevens, Daniel J.; Collins, Karen A.; Penev, Kaloyan; Quinn, Samuel N.; Latham, David W.; Villanueva, Steven, Jr.; Eastman, Jason D.; Kielkopf, John F.; Oberst, Thomas E.; Jensen, Eric L. N.; Cohen, David H.; Joner, Michael D.; Stephens, Denise C.; Relles, Howard; Corfini, Giorgio; Gregorio, Joao; Zambelli, Roberto; Esquerdo, Gilbert A.; Calkins, Michael L.; Berlind, Perry; Ciardi, David R.; Dressing, Courtney; Patel, Rahul; Gagnon, Patrick; Gonzales, Erica; Beatty, Thomas G.; Siverd, Robert J.; Labadie-Bartz, Jonathan; Kuhn, Rudolf B.; Colón, Knicole D.; James, David; Pepper, Joshua; Fulton, Benjamin J.; McLeod, Kim K.; Stockdale, Christopher; Calchi Novati, Sebastiano; DePoy, D. L.; Gould, Andrew; Marshall, Jennifer L.; Trueblood, Mark; Trueblood, Patricia; Johnson, John A.; Wright, Jason; McCrady, Nate; Wittenmyer, Robert A.; Johnson, Samson A.; Sergi, Anthony; Wilson, Maurice; Sliski, David H.
Abstract: We report the discovery of KELT-20b, a hot Jupiter transiting a V~ 7.6 early A star, HD 185603, with an orbital period of P? 3.47 days. Archival and follow-up photometry, Gaia parallax, radial velocities, Doppler tomography, and AO imaging were used to confirm the planetary nature of KELT-20b and characterize the system. From global modeling we infer that KELT-20 is a rapidly rotating (v\sin {I}_* ? 120 {km} {{{s}}}^-1) A2V star with an effective temperature of {T}_{eff}={8730}_-260⁺²⁵⁰ K, mass of {M}_* ={1.76}_-0.20^+0.14 {M}_? , radius of {R}_* ={1.561}_-0.064^+0.058 {R}_? , surface gravity of {log}{g}_* ={4.292}_-0.020^+0.017, and age of ? 600 {Myr}. The planetary companion has a radius of {R}_P={1.735}_-0.075^+0.070 {R}_{{J}}, a semimajor axis of a={0.0542}_-0.0021^+0.0014 au, and a linear ephemeris of {{BJD}}_{TDB}=2457503.120049+/- 0.000190 +E(3.4741070+/- 0.0000019). We place a 3? upper limit of ~ 3.5 {M}_{{J}} on the mass of the planet. Doppler tomographic measurements indicate that the planetary orbit normal is well aligned with the projected spin axis of the star (? =3\buildrel{\circ}\over{.} 4+/- 2\buildrel{\circ}\over{.} 1). The inclination of the star is constrained to 24\buildrel{\circ}\over{.} 4}} on the mass of the planet. Doppler tomographic measurements indicate that the planetary orbit normal is well aligned with the projected spin axis of the star (? =3\buildrel{\circ}\over{.} 4+/- 2\buildrel{\circ}\over{.} 1). The inclination of the star is constrained to 24\buildrel{\circ}\over{.} 4_* ⁹ {erg} {{{s}}}^-1 {{cm}}^-2, implying an equilibrium temperature of of ~2250 K, assuming zero albedo and complete heat redistribution. Due to the high stellar {T}_{eff}, KELT-20b also receives an ultraviolet (wavelength d<=slant 91.2 nm) insolation flux of ~ 9.1× {10}⁴ {erg} {{{s}}}^-1 {{cm}}^-2, possibly indicating significant atmospheric ablation. Together with WASP-33, Kepler-13 A, HAT-P-57, KELT-17, and KELT-9, KELT-20 is the sixth A star host of a transiting giant planet, and the third-brightest host (in V) of a transiting planet.