K2-79 and K2-222 photometry and radial velocity

DOI

We present mass and radius measurements of K2-79b and K2-222b, two transiting exoplanets orbiting active G-type stars observed with HARPS-N and K2. Their respective 10.99day and 15.39day orbital periods fall near periods of signals induced by stellar magnetic activity. The two signals might therefore interfere and lead to an inaccurate estimate of exoplanet mass. We present a method to mitigate these effects when radial velocity (RV) and activity-indicator observations are available over multiple observing seasons and the orbital period of the exoplanet is known. We perform correlation and periodogram analyses on subsets composed of each target's two observing seasons, in addition to the full data sets. For both targets, these analyses reveal an optimal season with little to no interference at the orbital period of the known exoplanet. We make a confident mass detection of each exoplanet by confirming agreement between fits to the full RV set and the optimal season. For K2-79b, we measure a mass of 11.8{+/-}3.6M{Earth} and a radius of 4.09{+/-}0.17R{Earth}. For K2-222b, we measure a mass of 8.0{+/-}1.8M{Earth} and a radius of 2.35{+/-}0.08R{Earth}. According to model predictions, K2-79b is a highly irradiated Uranus analog and K2-222b hosts significant amounts of water ice. We also present a RV solution for a candidate second companion orbiting K2-222 at 147.5days.

Identifier
DOI http://doi.org/10.26093/cds/vizier.51630041
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/AJ/163/41
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/163/41
Related Identifier http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/163/41
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/AJ/163/41
Provenance
Creator Nava C.; Lopez-Morales M.; Mortier A.; Zeng Li; Giles H.A.C.; Bieryla A.,Vanderburg A.; Buchhave L.A.; Poretti E.; Saar S.H.; Dumusque X.,Latham D.W.; Charbonneau D.; Damasso M.; Bonomo A.S.; Lovis C.,Collier Cameron A.; Eastman J.D.; Sozzetti A.; Cosentino R.; Pedani M.,Pepe F.; Molinari E.; Sasselov D.; Mayor M.; Stalport M.; Malavolta L.,Rice K.; Watson C.A.; Martinez Fiorenzano A.F.; Di Fabrizio L.
Publisher CDS
Publication Year 2022
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; Interdisciplinary Astronomy; Natural Sciences; Observational Astronomy; Physics; Stellar Astronomy