HD 35843: A Sun-like Star Hosting A Long Period Sub-Neptune And Inner Super-Earth
We report the discovery and confirmation of two planets orbiting the metal-poor Sun-like star, HD 35843 (TOI 4189). HD 35843 c is a temperate sub-Neptune transiting planet with an orbital period of 46.96 days that was first identified by Planet Hunters TESS.
We combine data from TESS and follow-up observations to rule out false-positive scenarios and validate the planet. We then use ESPRESSO radial velocities to confirm the planetary nature and characterize the planet’s mass and orbit.
Further analysis of these RVs reveals the presence of an additional planet, HD 35843 b, with a period of 9.90 days and a minimum mass of 5.84±0.84 M⊕.
For HD 35843 c, a joint photometric and spectroscopic analysis yields a radius of 2.54±0.08R⊕, a mass of 11.32±1.60M⊕, and an orbital eccentricity of e=0.15±0.07. With a bulk density of 3.80±0.70 g/cm3, the planet might be rocky with a substantial H2 atmosphere or it might be a “water world”.
With an equilibrium temperature of ∼480 K, HD 35843 c is among the coolest ∼5% of planets discovered by TESS. Combined with the host star’s relative brightness (V= 9.4), HD 35843 c is a promising target for atmospheric characterization that will probe this sparse population of temperate sub-Neptunes.
TESS target pixel files of HD 35843 (TIC 7422496) for all 5 sectors of observations made using tpfplotter Aller et al. (2020). The SPOC photometric aperture is highlighted in each panel. — astro-ph.EP
Katharine Hesse, Ismael Mireles, François Bouchy, Diana Dragomir, Solène Ulmer-Moll, Nora L. Eisner, Keivan G. Stassun, Samuel N. Quinn, Hugh P. Osborn, Sergio G. Sousa, Cristilyn N. Watkins, Karen A. Collins, Edward M. Bryant, Jonathan M. Irwin, Coel Hellier, Marshall C. Johnson, Carl Ziegler, Steve B. Howell, David R. Anderson, Daniel Bayliss, Allyson Bieryla, César Briceño, R. Paul Butler, David Charbonneau, Ryan Cloutier, Jeffrey Crane, Jason Dittmann, Jason D. Eastman, Sebastián A. Freigeiro, Benjamin J. Fulton, Samuel Gill, Maximilian Günther, Haedam Im, Jon M. Jenkins, Michelle Kunimoto, Baptiste Lavie, Monika Lendl, Michael B. Lund, Andrew W. Mann, Belinda Nicholson, David Osip, Martin Paegert, Nuno C. Santos, Richard P. Schwarz, Sara Seager, Stephen Shectman, Johanna Teske, Joseph D. Twicken, Stéphane Udry, Vincent Van Eylen, José Vinés López, Sharon X. Wang, Peter J. Wheatley, Joshua N. Winn, Edward E. Zuidema
Comments: Accepted in AJ; 31 pages; 22 figures
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2505.00898 [astro-ph.EP] (or arXiv:2505.00898v1 [astro-ph.EP] for this version)
https://doi.org/10.48550/arXiv.2505.00898
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Submission history
From: Katharine Hesse
[v1] Thu, 1 May 2025 22:22:52 UTC (18,880 KB)
https://arxiv.org/abs/2505.00898
Astrobiology,
