KELT-25 b and KELT-26 b: A Hot Jupiter and a Substellar Companion Transiting Young A Stars Observed by TESS
Cargile, Phillip A.; Bieryla, Allyson; Latham, David W.; Quinn, Samuel N.; Morton, Timothy D.; Kane, Stephen R.; Feliz, Dax L.; Pepper, Joshua; Stassun, Keivan G.; Siverd, Robert J.; Zhou, George; Bayliss, Daniel; Tan, Thiam-Guan; Kuhn, Rudolf B.; Howell, Steve B.; Horner, Jonathan; Henry, Todd J.; Ziegler, Carl; Collins, Karen A.; Vanderspek, Roland; Seager, Sara; Jenkins, Jon M.; Tokovinin, Andrei; Crane, Jeffrey D.; Teske, Johanna; Shectman, Stephen; Dragomir, Diana; Lund, Michael B.; Mann, Andrew W.; Everett, Mark E.; Rodriguez, Joseph E.; Stevens, Daniel J.; Beatty, Thomas G.; Gaudi, B. Scott; Labadie-Bartz, Jonathan; Penev, Kaloyan; Johnson, Marshall C.; Colón, Knicole D.; Evans, Phil; Yao, Xinyu; Stockdale, Chris; Eastman, Jason D.; Cohen, David H.; Curtis, Ivan A.; Gregorio, Joao; Jensen, Eric L. N.; Joner, Michael D.; Kielkopf, John F.; Manner, Mark; McLeod, Kim K.; Penny, Matthew T.; Reed, Phillip A.; Stephens, Denise C.; Villanueva, Steven, Jr.; Zambelli, Roberto; Bowler, Brendan P.; Fausnaugh, Michael; Matson, Rachel A.; Relles, Howard M.; Ting, Eric B.; Plavchan, Peter; James, David J.; Scott, Nicholas J.; Tinney, C. G.; Okumura, Jack; Quintana, Elisa V.; Wang, Sharon Xuesong; Wright, Duncan J.; Zhang, Hui; Paredes, Leonardo A.; James, Hodari-Sadiki; Jao, Wei-Chun; Glidden, Ana; Conti, Dennis M.; Thompson, Ian; Mengel, Matthew W.; Ciardi, David; Winn, Joshua; Addison, Brett; Rodríguez Martínez, Romy; Bouma, Luke; Depoy, D. L.; Khakpash, Somayeh; Marshall, Jennifer L.; Trueblood, Mark; Trueblood, Pat; Rothenberg, Jason; Bedding, Timothy; Wittenmyer, Robert; Kilby, Coleman; Butler, Paul; Günther, Max
United States, Brazil, Australia, Canada, Chile, United Kingdom, Portugal, South Africa, Italy, China, Spain
Abstract
We present the discoveries of KELT-25 b (TIC 65412605, TOI-626.01) and KELT-26 b (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 Transiting Exoplanet Survey Satellite (TESS) photometry. KELT-25 b is on a 4.40 day orbit around the V = 9.66 star CD-24 5016 ( ${T}_{\mathrm{eff}}={8280}_{-180}^{+440}$ K, M⋆ = ${2.18}_{-0.11}^{+0.12}$ M⊙), while KELT-26 b is on a 3.34 day orbit around the V = 9.95 star HD 134004 ( ${T}_{\mathrm{eff}}$ = ${8640}_{-240}^{+500}$ K, M⋆ = ${1.93}_{-0.16}^{+0.14}$ M⊙), which is likely an Am star. We have confirmed the substellar nature of both companions through detailed characterization of each system using ground-based and TESS photometry, radial velocity measurements, Doppler tomography, and high-resolution imaging. For KELT-25, we determine a companion radius of RP = ${1.64}_{-0.043}^{+0.039}$ RJ and a 3σ upper limit on the companion's mass of ∼64 MJ. For KELT-26 b, we infer a planetary mass and radius of MP = ${1.41}_{-0.51}^{+0.43}$ ${M}_{{\rm{J}}}$ and RP = ${1.94}_{-0.058}^{+0.060}$ RJ. From Doppler tomographic observations, we find KELT-26 b to reside in a highly misaligned orbit. This conclusion is weakly corroborated by a subtle asymmetry in the transit light curve from the TESS data. KELT-25 b appears to be in a well-aligned, prograde orbit, and the system is likely a member of the cluster Theia 449. * This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile.