2025A&A...695A.273Z

Query : 2025A&A...695A.273Z

2025A&A...695A.273Z - Astronomy and Astrophysics, volume 695A273 (2025/3-1)

A joint effort to discover and characterize two resonant mini-Neptunes around TOI-1803 with TESS, HARPS-N, and CHEOPS.

ZINGALES T., MALAVOLTA L., BORSATO L., TURRINI D., BONFANTI A., POLYCHRONI D., MANTOVAN G., NARDIELLO D., NASCIMBENI V., LANZA A.F., BEKKELIEN A., SOZZETTI A., BROEG C., NAPONIELLO L., LENDL M., BONOMO A.S., SIMON A.E., DESIDERA S., PIOTTO G., MANCINI L., HOOTON M.J., BIGNAMINI A., EGGER J.A., MAGGIO A., ALIBERT Y., LOCCI D., DELREZ L., BIASSONI F., FOSSATI L., CABONA L., LACEDELLI G., CARLEO I., LEONARDI P., ANDREUZZI G., BRANDEKER A., COSENTINO R., CORREIA A.C.M., CLAUDI R., ALONSO R., DAMASSO M., WILSON T.G., BARCZY T., PINAMONTI M., BAKER D., BARKAOUI K., BARRADO NAVASCUES D., BARROS S.C.C., BAUMJOHANN W., BECK T., BEICHMAN C., BENZ W., BIERYLA A., BILLOT N., BOSCH-CABOT P., BOUMA L.G., CIARDI D.R., COLLIER CAMERON A., COLLINS K.A., CROSSFIELD I.J.M., CSIZMADIA S., CUBILLOS P.E., DAVIES M.B., DELEUIL M., DELINE A., DEMANGEON O.D.S., DEMORY B.-O., DEREKAS A., DRAGOMIR D., EDWARDS B., EHRENREICH D., ERIKSON A., FALK B., FORTIER A., FRIDLUND M., FUKUI A., GANDOLFI D., GAZEAS K., GILLON M., GONZALES E., GUDEL M., GUERRA P., GUNTHER M.N., HEITZMANN A., HELLING C., HOWELL S.B., ISAAK K.G., JENKINS J., KISS L.L., KORTH J., LAM K.W.F., LASKAR J., LECAVELIER DES ETANGS A., MAGRIN D., MATSON R., MATTHEWS E.C., MAXTED P.F.L., McDERMOTT S., MUNARI M., MORDASINI C., NARITA N., OLOFSSON G., OTTENSAMER R., PAGANO I., PALLE E., PETER G., POLLACCO D., QUELOZ D., RAGAZZONI R., RANDO N., RATTI F., RAUER H., RIBAS I., SALMON S., SANTOS N.C., SCANDARIATO G., SEAGER S., SEGRANSAN D., SMITH A.M.S., SCHLIEDER J., SCHWARZ R.P., SHPORER A., SOUSA S.G., STALPORT M., STEINBERGER M., SULIS S., SZABO G.M., TWICKEN J.D., UDRY S., VAN GROOTEL V., VENTURINI J., VILLAVER E., WALTON N.A. and WINN J.N.

Abstract (from CDS):

Context. The discovery and characterization of mini-Neptunes hold a potentially crucial impact on planetary formation and evolution theories. Estimating their orbital parameters and atmospheric properties would provide valuable hints to improve formation and atmospheric models.
Aims. We present the discovery of two mini-Neptunes near a 2:1 orbital resonance configuration orbiting the K0 star TOI-1803. We describe in detail their orbital architecture and suggest some possible formation and evolution scenarios.
Methods. Using CHEOPS, TESS, and HARPS-N datasets, we estimated 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 assumed different atmospheric compositions and defined possible atmospheric scenarios with simulated JWST observations.
Results. 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 have revealed significant transit timing variations (TTV) with an amplitude of ∼10 min and ∼40 min, respectively, for planets b and -c. With the masses computed from the radial velocities dataset, we obtained a density of (0.39 ± 0.10) ρ⊕ and (0.076 ± 0.038) ρ⊕ for planets 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. With NIRSpec observations, we could understand whether the planet has kept its primary atmosphere or not, which would constrain our formation models.
Conclusions. 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-Neptunes known so far, and it is of great interest among the scientific community since it could constrain current formation scenarios. JWST observations could give us valuable insights to characterize this interesting system.

Abstract Copyright: © The Authors 2025

Journal keyword(s): planets and satellites: detection - planets and satellites: dynamical evolution and stability - planets and satellites: formation - planets and satellites: fundamental parameters - planets and satellites: interiors

Simbad objects: 4

goto Full paper

goto View the references in ADS

Number of rows : 4
N Identifier Otype ICRS (J2000)
RA 		ICRS (J2000)
DEC 		Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2026 		#notes
1 TOI-1803 PM* 11 52 11.1743830944 +35 10 18.430669236   13.22 11.87     K0 17 0
2 TOI-1803c Pl 11 52 11.1743830944 +35 10 18.430669236           ~ 2 0
3 TOI-1803b Pl 11 52 11.1743830944 +35 10 18.430669236           ~ 3 0
4 WASP-39b Pl 14 29 18.4151689656 -03 26 40.204480380           ~ 345 1

To bookmark this query, right click on this link: simbad:objects in 2025A&A...695A.273Z and select 'bookmark this link' or equivalent in the popup menu