Exoplanetology: Exoplanets & Exomoons

A Joint Effort To Discover And Characterize Two Resonant Mini Neptunes Around TOI-1803 With TESS, HARPS-N And CHEOPS

By Keith Cowing
Status Report
astro-ph.EP
December 16, 2024
Filed under , , , , , , , , ,
A Joint Effort To Discover And Characterize Two Resonant Mini Neptunes Around TOI-1803 With TESS, HARPS-N And CHEOPS
TESS aperture field around the target star TOI-1803. (Image generated with tpfplotter, Aller et al. (2020)). — astro-ph.EP

We present the discovery of two mini Neptunes near a 2:1 orbital resonance configuration orbiting the K0 star TOI-1803. We describe their orbital architecture in detail and suggest some possible formation and evolution scenarios.

Using CHEOPS, TESS, and HARPS-N datasets we can estimate the radius and the mass of both planets. We used a multidimensional Gaussian Process with a quasi-periodic kernel to disentangle the planetary components from the stellar activity in the HARPS-N dataset.

We performed dynamical modeling to explain the orbital configuration and performed planetary formation and evolution simulations. For the least dense planet, we define possible atmospheric characterization scenarios with simulated JWST observations.

TOI-1803 b and TOI-1803 c have orbital periods of ∼6.3 and ∼12.9 days, respectively, residing in close proximity to a 2:1 orbital resonance. Ground-based photometric follow-up observations revealed significant transit timing variations (TTV) with an amplitude of ∼10 min and ∼40 min, respectively, for planet -b and -c.

With the masses computed from the radial velocities data set, we obtained a density of (0.39±0.10) ρearth and (0.076±0.038) ρearth for planet -b and -c, respectively. TOI-1803 c is among the least dense mini Neptunes currently known, and due to its inflated atmosphere, it is a suitable target for transmission spectroscopy with JWST. We report the discovery of two mini Neptunes close to a 2:1 orbital resonance.

The detection of significant TTVs from ground-based photometry opens scenarios for a more precise mass determination. TOI-1803 c is one of the least dense mini Neptune known so far, and it is of great interest among the scientific community since it could constrain our formation scenarios.

T. Zingales, L. Malavolta, L. Borsato, D. Turrini, A. Bonfanti, D. Polychroni, G. Mantovan, D. Nardiello, V. Nascimbeni, A. F. Lanza, A. Bekkelien, A. Sozzetti, C. Broeg, L. Naponiello, M. Lendl, A. S. Bonomo, A. E. Simon, S. Desidera, G. Piotto, L. Mancini, M. J. Hooton, A. Bignamini, J. A. Egger, A. Maggio, Y. Alibert, D. Locci, L. Delrez, F. Biassoni, L. Fossati, L. Cabona, G. Lacedelli, I. Carleo, P. Leonardi, G. Andreuzzi, A. Brandeker, R. Cosentino, A. C. M. Correia, R. Claudi, R. Alonso, M. Damasso, T. G. Wilson, T. Bàrczy, M. Pinamonti, D. Baker, K. Barkaoui, D. Barrado Navascues, S. C. C. Barros, W. Baumjohann, T. Beck, C. Beichman, W. Benz, A. Bieryla, N. Billot, P. Bosch-Cabot, L. G. Bouma, D. R. Ciardi, A. Collier Cameron, K. A. Collins, Ian J. M. Crossfield, Sz. Csizmadia, P. E. Cubillos, M. B. Davies, M. Deleuil, A. Deline, O. D. S. Demangeon, B. O. Demory, A. Derekas, D. Dragomir, B. Edwards, D. Ehrenreich, A. Erikson, B. Falk, A. Fortier, M. Fridlund, A. Fukui, D. Gandolfi, K. Gazeas, M. Gillon, E. Gonzales, M. Gudel, P. Guerra, M. N. Guunther, A. Heitzmann, Ch. Helling, S. B. Howell, K. G. Isaak, J. Jenkins, L. L. Kiss, J. Korth, K. W. F. Lam, J. Laskar, A. Lecavelier des Etangs, D. Magrin, R. Matson, E. C. Matthews, P. F. L. Maxted, S. McDermott, M. Munari, C. Mordasini, N. Narita et al. (33 additional authors not shown)

Comments: 26 Pages, 21 Figures Accepted for Publication in Astronomy & Astrophysics
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2412.05423 [astro-ph.EP] (or arXiv:2412.05423v1 [astro-ph.EP] for this version)
https://doi.org/10.48550/arXiv.2412.05423
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Submission history
From: Tiziano Zingales
[v1] Fri, 6 Dec 2024 21:08:27 UTC (21,666 KB)
https://arxiv.org/abs/2412.05423
Astrobiology

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻