TOI-1518 is a fast-rotating F-type star located approximately 742 light-years away in the constellation of Cepheus.
Also designated as TIC 427761355 and BD+66 1610, it is almost two times larger and more massive than the Sun.
The newfound planet, TOI-1518b, is an inflated gas giant about 1.9 times the size of Jupiter.
It orbits its parent star once every 1.9 days at a distance of 0.04 AU (astronomical units).
“The new planet falls within the category of ultrahot Jupiters, which have equilibrium temperatures exceeding 2,000 K,” said Yale University astronomer Samuel Cabot and colleagues.
“Many ultrahot Jupiters contain vaporized metals, both neutral and ionized, in their upper atmospheres.”
“These metals and molecules containing them are recognized as strong sources of opacity in the optical and near-ultraviolet regions.TOI-1518b was first identified as a candidate transiting exoplanet in photometric data from NASA’s Transiting Exoplanet Survey Satellite (TESS).
The presence of the planet was then confirmed using high-resolution optical transmission spectra from the EXtreme PREcision Spectrometer (EXPRES) on the Lowell Discovery Telescope.
Additionally, Cabot and co-authors detected iron vapor in the atmosphere of TOI-1518b.
“TOI-1518b is highly inflated, which makes it amenable to intensive atmospheric characterization,” they said.
“The equilibrium temperature of TOI-1518b (2,492 K) is in the regime where the planet might exhibit a thermal inversion.”
“This, combined with the brightness of the host star, makes TOI-1518b an attractive target for follow-up emission spectroscopy.”
