Kepler-77b: a very low albedo, Saturn-mass transiting planet around a metal-rich solar-like star
We report the discovery of Kepler-77b (alias KOI-127.01), a Saturn-mass transiting planet in a 3.6-day orbit around a metal-rich solar-like star. We combined the publicly available Kepler photometry (quarters 1-13) with high-resolution spectroscopy from the Sandiford@McDonald and FIES@NOT spectrogra...
| Main Authors: | , , , , , , , , , , , , , , , , , , , , |
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| Format: | Journal article |
| Language: | English |
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2013
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| _version_ | 1826289119193464832 |
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| author | Gandolfi, D Parviainen, H Fridlund, M Hatzes, A Deeg, H Frasca, A Lanza, A Moroni, P Tognelli, E McQuillan, A Aigrain, S Alonso, R Antoci, V Cabrera, J Carone, L Csizmadia, S Djupvik, A Guenther, E Jessen-Hansen, J Ofir, A Telting, J |
| author_facet | Gandolfi, D Parviainen, H Fridlund, M Hatzes, A Deeg, H Frasca, A Lanza, A Moroni, P Tognelli, E McQuillan, A Aigrain, S Alonso, R Antoci, V Cabrera, J Carone, L Csizmadia, S Djupvik, A Guenther, E Jessen-Hansen, J Ofir, A Telting, J |
| author_sort | Gandolfi, D |
| collection | OXFORD |
| description | We report the discovery of Kepler-77b (alias KOI-127.01), a Saturn-mass transiting planet in a 3.6-day orbit around a metal-rich solar-like star. We combined the publicly available Kepler photometry (quarters 1-13) with high-resolution spectroscopy from the Sandiford@McDonald and FIES@NOT spectrographs. We derived the system parameters via a simultaneous joint fit to the photometric and radial velocity measurements. Our analysis is based on the Bayesian approach and is carried out by sampling the parameter posterior distributions using a Markov chain Monte Carlo simulation. Kepler-77b is a moderately inflated planet with a mass of Mp=0.430+/-0.032 Mjup, a radius of Rp=0.960+/-0.016 Rjup, and a bulk density of 0.603+/-0.055 g/cm^3. It orbits a slowly rotating (P=36+/-6 days) G5V star with M*=0.95+/-0.04 Msun, R*=0.99+/-0.02 Rsun, Teff=5520+/-60 K, [M/H]=0.20+/-0.05, that has an age of 7.5+/-2.0 Gyr. The lack of detectable planetary occultation with a depth higher than about 10 ppm implies a planet geometric and Bond albedo of Ag<0.087+/-0.008 and Ab<0.058+/-0.006, respectively, placing Kepler-77b among the gas-giant planets with the lowest albedo known so far. We found neither additional planetary transit signals nor transit-timing variations at a level of about 0.5 minutes, in accordance with the trend that close-in gas giant planets seem to belong to single-planet systems. The 106 transits observed in short-cadence mode by Kepler for nearly 1.2 years show no detectable signatures of the planet's passage in front of starspots. We explored the implications of the absence of detectable spot-crossing events for the inclination of the stellar spin-axis, the sky-projected spin-orbit obliquity, and the latitude of magnetically active regions. |
| first_indexed | 2024-03-07T02:24:02Z |
| format | Journal article |
| id | oxford-uuid:a4f928a7-cf8d-481b-87c9-a3febc08111b |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T02:24:02Z |
| publishDate | 2013 |
| record_format | dspace |
| spelling | oxford-uuid:a4f928a7-cf8d-481b-87c9-a3febc08111b2022-03-27T02:37:23ZKepler-77b: a very low albedo, Saturn-mass transiting planet around a metal-rich solar-like starJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:a4f928a7-cf8d-481b-87c9-a3febc08111bEnglishSymplectic Elements at Oxford2013Gandolfi, DParviainen, HFridlund, MHatzes, ADeeg, HFrasca, ALanza, AMoroni, PTognelli, EMcQuillan, AAigrain, SAlonso, RAntoci, VCabrera, JCarone, LCsizmadia, SDjupvik, AGuenther, EJessen-Hansen, JOfir, ATelting, JWe report the discovery of Kepler-77b (alias KOI-127.01), a Saturn-mass transiting planet in a 3.6-day orbit around a metal-rich solar-like star. We combined the publicly available Kepler photometry (quarters 1-13) with high-resolution spectroscopy from the Sandiford@McDonald and FIES@NOT spectrographs. We derived the system parameters via a simultaneous joint fit to the photometric and radial velocity measurements. Our analysis is based on the Bayesian approach and is carried out by sampling the parameter posterior distributions using a Markov chain Monte Carlo simulation. Kepler-77b is a moderately inflated planet with a mass of Mp=0.430+/-0.032 Mjup, a radius of Rp=0.960+/-0.016 Rjup, and a bulk density of 0.603+/-0.055 g/cm^3. It orbits a slowly rotating (P=36+/-6 days) G5V star with M*=0.95+/-0.04 Msun, R*=0.99+/-0.02 Rsun, Teff=5520+/-60 K, [M/H]=0.20+/-0.05, that has an age of 7.5+/-2.0 Gyr. The lack of detectable planetary occultation with a depth higher than about 10 ppm implies a planet geometric and Bond albedo of Ag<0.087+/-0.008 and Ab<0.058+/-0.006, respectively, placing Kepler-77b among the gas-giant planets with the lowest albedo known so far. We found neither additional planetary transit signals nor transit-timing variations at a level of about 0.5 minutes, in accordance with the trend that close-in gas giant planets seem to belong to single-planet systems. The 106 transits observed in short-cadence mode by Kepler for nearly 1.2 years show no detectable signatures of the planet's passage in front of starspots. We explored the implications of the absence of detectable spot-crossing events for the inclination of the stellar spin-axis, the sky-projected spin-orbit obliquity, and the latitude of magnetically active regions. |
| spellingShingle | Gandolfi, D Parviainen, H Fridlund, M Hatzes, A Deeg, H Frasca, A Lanza, A Moroni, P Tognelli, E McQuillan, A Aigrain, S Alonso, R Antoci, V Cabrera, J Carone, L Csizmadia, S Djupvik, A Guenther, E Jessen-Hansen, J Ofir, A Telting, J Kepler-77b: a very low albedo, Saturn-mass transiting planet around a metal-rich solar-like star |
| title | Kepler-77b: a very low albedo, Saturn-mass transiting planet around a
metal-rich solar-like star |
| title_full | Kepler-77b: a very low albedo, Saturn-mass transiting planet around a
metal-rich solar-like star |
| title_fullStr | Kepler-77b: a very low albedo, Saturn-mass transiting planet around a
metal-rich solar-like star |
| title_full_unstemmed | Kepler-77b: a very low albedo, Saturn-mass transiting planet around a
metal-rich solar-like star |
| title_short | Kepler-77b: a very low albedo, Saturn-mass transiting planet around a
metal-rich solar-like star |
| title_sort | kepler 77b a very low albedo saturn mass transiting planet around a metal rich solar like star |
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