KELT-25b and KELT-26b: A Hot Jupiter and a Substellar Companion Transiting Young A-stars Observed by TESS
Creators: name: Martínez, Romy Rodríguez
name: Gaudi, B. Scott
name: Rodriguez, Joseph E.
name: Zhou, George
name: Labadie-Bartz, Jonathan
name: Quinn, Samuel N.
name: Penev, Kaloyan Minev
name: Tan, Thiam-Guan
name: Latham, David W.
name: Paredes, Leonardo A.
name: Kielkopf, John
name: Addison, Brett C.
name: Wright, Duncan J.
name: Teske, Johanna K.
name: Howell, Steve B.
name: Ciardi, David R.
name: Ziegler, Carl
name: Stassun, Keivan G.
name: Johnson, Marshall C.
name: Eastman, Jason D.
name: Siverd, Robert J.
name: Beatty, Thomas G.
name: Bouma, Luke G.
name: Pepper, Joshua
name: Lund, Michael B.
name: Villanueva, Steven
name: Stevens, Daniel J.
name: Jensen, Eric L. N.
name: Kilby, Coleman
name: Cohen, David H.
name: Bayliss, Daniel
name: Bieryla, Allyson
name: Cargile, Phillip A.
name: Collins, Karen A.
name: Conti, Dennis M.
name: Colon, Knicole D.
name: Curtis, Ivan A.
name: DePoy, Darren L.
name: Evans, Phil A.
name: Feliz, Dax
name: Gregorio, Joao
name: Rothenberg, Jason
name: James, David J.
name: Penny, Matthew T.
name: Reed, Phillip A.
name: Relles, Howard M.
name: Stephens, Denise C.
name: Joner, Michael D.
name: Kuhn, Rudolf B.
name: Stockdale, Chris
name: Trueblood, Mark
name: Trueblood, Patricia
name: Yao, Xinyu
name: Zambelli, Roberto
name: Vanderspek, Roland
name: Seager, Sara
name: Winn, Joshua N.
name: Jenkins, Jon M.
name: Henry, Todd J.
name: James, Hodari-Sadiki
name: Jao, Wei-Chun
name: Wang, Sharon X.
name: Butler, R. Paul
name: Crane, Jeffrey D.
name: Thompson, Ian B.
name: Schectman, Stephen
name: Wittenmyer, Robert A.
name: Bedding, Timothy R.
name: Okumura, Jack
name: Plavchan, Peter
name: Bowler, Brendan P.
name: Horner, Jonathan
name: Kane, Stephen R.
name: Mengel, Matthew W.
name: Morton, Timothy D.
name: Tinney, C. G.
name: Zhang, Hui
name: Scott, Nicholas J.
name: Matson, Rachel A.
name: Everett, Mark E.
name: Tokovinin, Andrei
name: Mann, Andrew W.
name: Dragomir, Diana
name: Guenther, Maximilian N.
name: Ting, Eric B.
name: Fausnaugh, Michael
name: Glidden, Ana
name: Quintana, Elisa V.
name: Manner, Mark
name: Marshall, Jennifer L.
name: McLeod, Kim K.
name: Khakpash, Somayeh
Publisher: name: arXiv
Year: 2019
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: We present the discoveries of KELT-25b (TIC 65412605, TOI-626.01) and KELT-26b (TIC 160708862, TOI-1337.01), two transiting companions orbiting relatively bright, early A-stars. The transit signals were initially detected by the KELT survey, and subsequently confirmed by \textit{TESS} photometry. KELT-25b is on a 4.40-day orbit around the V = 9.66 star CD-24 5016 ($T_{\rm eff} = 8280^{+440}_{-180}$ K, $M_{\star}$ = $2.18^{+0.12}_{-0.11}$ $M_{\odot}$), while KELT-26b is on a 3.34-day orbit around the V = 9.95 star HD 134004 ($T_{\rm eff}$ =$8640^{+500}_{-240}$ K, $M_{\star}$ = $1.93^{+0.14}_{-0.16}$ $M_{\odot}$), which is likely an Am star. We have confirmed the sub-stellar nature of both companions through detailed characterization of each system using ground-based and \textit{TESS} photometry, radial velocity measurements, Doppler Tomography, and high-resolution imaging. For KELT-25, we determine a companion radius of $R_{\rm P}$ = $1.64^{+0.039}_{-0.043}$ $R_{\rm J}$, and a 3-sigma upper limit on the companion's mass of $\sim64~M_{\rm J}$. For KELT-26b, we infer a planetary mass and radius of $M_{\rm P}$ = $1.41^{+0.43}_{-0.51}$ $M_{\rm J}$ and $R_{\rm P}$ = $1.940^{+0.060}_{-0.058}$ $R_{\rm J}$. From Doppler Tomographic observations, we find KELT-26b to reside in a highly misaligned orbit. This conclusion is weakly corroborated by a subtle asymmetry in the transit light curve from the \textit{TESS} data. KELT-25b appears to be in a well-aligned, prograde orbit, and the system is likely a member of a cluster or moving group.
description: 24 pages, 18 figures, 8 tables