English

TOI-2498 b: A hot bloated super-Neptune within the Neptune desert

Earth and Planetary Astrophysics 2023-05-24 v1

Abstract

We present the discovery and confirmation of a transiting hot, bloated Super-Neptune using photometry from TESS and LCOGT and radial velocity measurements from HARPS. The host star TOI-2498 is a V = 11.2, G-type (Teff_{eff} = 5905 ±\pm 12K) solar-like star with a mass of 1.12 ±\pm 0.02 M_{\odot} and a radius of 1.26 ±\pm 0.04 R_{\odot}. The planet, TOI-2498 b, orbits the star with a period of 3.7 days, has a radius of 6.1 ±\pm 0.3 R_{\oplus}, and a mass of 35 ±\pm 4 M_{\oplus}. This results in a density of 0.86 ±\pm 0.25 g cm3^{-3}. TOI-2498 b resides on the edge of the Neptune desert; a region of mass-period parameter space in which there appears to be a dearth of planets. Therefore TOI-2498 b is an interesting case to study to further understand the origins and boundaries of the Neptune desert. Through modelling the evaporation history, we determine that over its \sim3.6 Gyr lifespan, TOI-2498 b has likely reduced from a Saturn sized planet to its current radius through photoevaporation. Moreover, TOI-2498 b is a potential candidate for future atmospheric studies searching for species like water or sodium in the optical using high-resolution, and for carbon based molecules in the infra-red using JWST.

Keywords

Cite

@article{arxiv.2305.06950,
  title  = {TOI-2498 b: A hot bloated super-Neptune within the Neptune desert},
  author = {Ginger Frame and David J. Armstrong and Heather M. Cegla and Jorge Fernández Fernández and Ares Osborn and Vardan Adibekyan and Karen A. Collins and Elisa Delgado Mena and Steven Giacalone and John F. Kielkopf and Nuno C. Santos and Sérgio G. Sousa and Keivan G. Stassun and Carl Ziegler and David R. Anderson and Susana C. C. Barros and Daniel Bayliss and César Briceño and Dennis M. Conti and Courtney D. Dressing and Xavier Dumusque and Pedro~Figueira and William Fong and Samuel Gill and Faith Hawthorn and Jon M. Jenkins and Eric L. N. Jensen and Marcelo Aron F. Keniger and David W. Latham and Nicholas Law and Jack J. Lissauer and Andrew W. Mann and Louise D. Nielsen and Hugh Osborn and Martin Paegert and Sara Seager and Richard P. Schwarz and Avi Shporer and Gregor Srdoc and Paul A. Strøm and Joshua N. Winn and Peter J. Wheatley},
  journal= {arXiv preprint arXiv:2305.06950},
  year   = {2023}
}

Comments

13 pages, 11 figures, accepted for publication in MNRAS