KELT-25 b and KELT-26 b: A Hot Jupiter and a Substellar Companion Transiting Young A Stars Observed by TESS
Romy Rodríguez Martínez, B. Scott Gaudi, Joseph E. Rodriguez, George Zhou, Jonathan Labadie-Bartz, Samuel N. Quinn, K. Penev, Tan, Thiam-Guan, David W. Latham, Leonardo A. Paredes, John F. Kielkopf, Brett Addison, D. J. Wright, Johanna Teske, Steve B. Howell, David R. Ciardi, Carl Ziegler, Keivan G. Stassun, Marshall C. Johnson, Jason D. Eastman, Robert J. Siverd, Thomas G. Beatty, Luke G. Bouma, T. R. Bedding, Joshua Pepper, Joshua N. Winn, Michael B. Lund, Steven Villanueva, Daniel J. Stevens, Eric L. N. Jensen, C. M. Kilby, Jeffrey D. Crane, Andreï Tokovinin, Everett, Mark E., Tinney, C. G., Fausnaugh, Michael, Cohen, David H., Bayliss, Daniel, Bieryla, Allyson, Cargile, Phillip A., Collins, Karen A., Conti, Dennis M., Colon, Knicole D., Curtis, Ivan A., DePoy, D. L., Evans, Phil, Feliz, Dax L., Gregorio, Joao, Rothenberg, Jason, James, David J., Joner, Michael D., Kuhn, Rudolf B., Manner, Mark, Khakpash, Somayeh, Marshall, Jennifer L., McLeod, Kim K., Penny, Matthew T., Reed, Phillip A., Relles, Howard M., Stephens, Denise C., Stockdale, Chris, Trueblood, Mark, Trueblood, Pat, Yao, Xinyu, Zambelli, Roberto, Vanderspek, Roland, Seager, Sara, Jenkins, Jon M., Henry, Todd J., James, Hodari-Sadiki, Jao, Wei-Chun, Wang, Sharon Xuesong, Butler, Paul, Thompson, Ian, Shectman, Stephen, Wittenmyer, Robert, Bowler, Brendan P., Horner, Jonathan, Kane, Stephen R., Mengel, Matthew W., Morton, Timothy D., Okumura, Jack, Plavchan, Peter, Zhang, Hui, Scott, Nicholas J., Matson, Rachel A., Mann, Andrew W., Dragomir, Diana, Gunther, Max, Ting, Eric B., Glidden, Ana, Quintana, Elisa V.
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 (Teff=8280-180+440 K, M ∗ = 2.18-0.11+0.12 M o˙), while KELT-26 b is on a 3.34 day orbit around the V = 9.95 star HD 134004 (Teff = 8640-240+500 K, M ∗ = 1.93-0.16+0.14 M o˙), 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 R P = 1.64-0.043+0.039 R J and a 3σ upper limit on the companion's mass of ∼64 M J. For KELT-26 b, we infer a planetary mass and radius of M P = 1.41-0.51+0.43MJ and R P = 1.94-0.058+0.060 R J. 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.