TOI-1518b: A Misaligned Ultra-hot Jupiter with Iron in Its Atmosphere

Cabot, Samuel H. C. and Bello-Arufe, Aaron and Mendonca, Joao M. and Tronsgaard, Rene and Wong, Ian and Zhou, George ORCID: https://orcid.org/0000-0002-4891-3517 and Buchhave, Lars A. and Fischer, Debra A. and Stassun, Keivan G. and Antoci, Victoria and Baker, David and Belinski, Alexander A. and Benneke, Bjorn and Bouma, Luke G. and Christiansen, Jessie L. and Collins, Karen A. and Goliguzova, Maria V. and Hagey, Simone and Jenkins, Jon M. and Jensen, Eric L. N. and Kidwell, Richard C., Jr. and Laloum, Didier and Massey, Bob and McLeod, Kim K. and Latham, David W. and Morgan, Edward H. and Ricker, George and Safonov, Boris S. and Schlieder, Joshua E. and Seager, Sara and Shporer, Avi and Smith, Jeffrey C. and Srdoc, Gregor and Strakhov, Ivan A. and Torres, Guillermo and Twicken, Joseph D. and Vanderspek, Roland and Vezie, Michael and Winn, Joshua N. (2021) TOI-1518b: A Misaligned Ultra-hot Jupiter with Iron in Its Atmosphere. The Astronomical Journal, 162 (5):218. pp. 1-19. ISSN 0004-6256


Abstract

We present the discovery of TOI-1518b-an ultra-hot Jupiter orbiting a bright star (V=8.95). The transiting planet is confirmed using high-resolution optical transmission spectra from EXPRES. It is inflated, with Rp=1.875±0.053 RJ, and exhibits several interesting properties, including a misaligned orbit ( - 240.34+0.98 0.93 degrees) and nearly grazing transit ( = - b 0.9036+0.0053 0.0061). The planet orbits a fast-rotating F0 host star (Teff;7300 K) in 1.9 days and experiences intense irradiation. Notably, the TESS data show a clear secondary eclipse with a depth of 364±28 ppm and a significant phase-curve signal, from which we obtain a relative day-night planetary flux difference of roughly 320 ppm and a 5.2s detection of ellipsoidal distortion on the host star. Prompted by recent detections of atomic and ionized species in ultrahot Jupiter atmospheres, we conduct an atmospheric cross-correlation analysis. We detect neutral iron (5.2s), at = - K 157+ p 44 68 km s-1 and = - - V 16+ sys 4 2, adding another object to the small sample of highly irradiated gas-giant planets with Fe detections in transmission. Detections so far favor particularly inflated gas giants with radii 1.78 RJ, which may be due to observational bias. With an equilibrium temperature of Teq=2492±38 K and a measured dayside brightness temperature of 3237±59 K (assuming zero geometric albedo), TOI-1518b is a promising candidate for future emission spectroscopy to probe for a thermal inversion.


Statistics for USQ ePrint 44974
Statistics for this ePrint Item
Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Faculty/School / Institute/Centre: Current - Institute for Advanced Engineering and Space Sciences - Centre for Astrophysics (1 Aug 2018 -)
Faculty/School / Institute/Centre: Current - Institute for Advanced Engineering and Space Sciences - Centre for Astrophysics (1 Aug 2018 -)
Date Deposited: 02 Mar 2022 01:30
Last Modified: 30 Mar 2022 03:47
Uncontrolled Keywords: Exoplanet atmospheres; Transit photometry; High resolution spectroscopy; Astrophysics - Earth and Planetary; Astrophysics
Fields of Research (2020): 51 PHYSICAL SCIENCES > 5101 Astronomical sciences > 510109 Stellar astronomy and planetary systems
Socio-Economic Objectives (2020): 28 EXPANDING KNOWLEDGE > 2801 Expanding knowledge > 280120 Expanding knowledge in the physical sciences
Funding Details:
Identification Number or DOI: https://doi.org/10.3847/1538-3881/ac1ba3
URI: http://eprints.usq.edu.au/id/eprint/44974

Actions (login required)

View Item Archive Repository Staff Only