HD 15906 CHEOPS PIPE and WASP lightcurves

We report the discovery of two warm sub-Neptunes transiting the bright (G=9.5mag) K-dwarf HD 15906 (TOI 461, TIC 4646810). This star was observed by the Transiting Exoplanet Survey Satellite (TESS) in sectors 4 and 31, revealing two small transiting planets. The inner planet, HD 15906 b, was detected with an unambiguous period but the outer planet, HD 15906 c, showed only two transits separated by ~734 days, leading to 36 possible values of its period. We performed follow-up observations with the CHaracterising ExOPlanet Satellite (CHEOPS) to confirm the true period of HD 15906 c and improve the radius precision of the two planets. From TESS, CHEOPS and additional ground-based photometry, we find that HD 15906 b has a radius of 2.24+/-0.08 R_{Earth} and a period of 10.924709+/-0.000032 days, whilst HD 15906 c has a radius of 2.93^+0.07^-0.06_R_{Earth} and a period of 21.583298^+0.000052^-0.000055_ days. Assuming zero bond albedo and full day-night heat redistribution, the inner and outer planet have equilibrium temperatures of 668+/-13K and 532+/-10K, respectively. The HD 15906 system has become one of only six multiplanet systems with two warm (=10mag). It is an excellent target for detailed characterisation studies to constrain the composition of sub-Neptune planets and test theories of planet formation and evolution.

Identifier
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/MNRAS/523/3090
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/523/3090
Related Identifier http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/523/3090
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/MNRAS/523/3090
Provenance
Creator Tuson A.; Queloz D.; Osborn H.P.; Wilson T.G.; Hooton M.J.; Beck M.,Lendl M.; Olofsson G.; Fortier A.; Bonfanti A.; Brandeker A.; Buchhave L.A.,Collier Cameron A.; Ciardi D.R.; Collins K.A.; Gandolfi D.; Garai Z.,Giacalone S.; Gomes da Silva J.; Howell S.B.; Patel J.A.; Persson C.M.,Serrano L.M.; Sousa S.G.; Ulmer-Moll S.; Vanderburg A.; Ziegler C.,Alibert Y.; Alonso R.; Anglada G.; Barczy T.; Barrado Navascues D.,Barros S.C.C.; Baumjohann W.; Beck T.; Benz W.; Billot N.; Bonfils X.,Borsato L.; Broeg C.; Cabrera J.; Charnoz S.; Conti D.M.; Csizmadia Sz.,Cubillos P.E.; Davies M.B.; Deleuil M.; Delrez L.; Demangeon O.D.S.,Demory B.-O.; Dragomir D.; Dressing C.D.; Ehrenreich D.; Erikson A.,Essack Z.; Farinato J.; Fossati L.; Fridlund M.; Furlan E.; Gill H.,Gillon M.; Gnilka C.L.; Gonzales E.; Gudel M.; Gunther M.N.; Hoyer S.,Isaak K.G.; Jenkins J.M.; Kiss L.L.; Laskar J.; Latham D.W.; Law N.,Lecavelier des Etangs A.; Lo Curto G.; Lovis C.; Luque R.; Magrin D.,Mann A.W.; Maxted P.F.L.; Mayor M.; McDermott S.; Mecina M.; Mordasini C.,Mortier A.; Nascimbeni V.; Ottensamer R.; Pagano I.; Palle E.; Peter G.,Piotto G.; Pollacco D.; Pritchard T.; Ragazzoni R.; Rando N.; Ratti F.,Rauer H.; Ribas I.; Ricker G.R.; Rieder M.; Santos N.C.; Savel A.B.,Scandariato G.; Schwarz R.P.; Seager S.; Segransan D.; Shporer A.,Simon A.E.; Smith A.M.S.; Steller M.; Stockdale C.; Szabo Gy.M.,Thomas N.; Torres G.; Tronsgaard R.; Udry S.; Ulmer B.; Van Grootel V.,Vanderspek R.; Venturini J.; Walton N.A.; Winn J.N.; Wohler B.
Publisher CDS
Publication Year 2023
Rights https://cds.unistra.fr/vizier-org/licences_vizier.html
OpenAccess true
Contact CDS support team <cds-question(at)unistra.fr>
Representation
Resource Type Dataset; AstroObjects
Discipline Astrophysics and Astronomy; Exoplanet Astronomy; Natural Sciences; Observational Astronomy; Physics; Stellar Astronomy