J/A+A/590/A112 Kepler-539 CAFE radial velocity measurements (Mancini+, 2016)
Kepler-539: A young extrasolar system with two giant planets on wide orbits
and in gravitational interaction.
Mancini L., Lillo-Box J., Southworth J., Borsato L., Gandolfi D.,
Ciceri S., Barrado D., Brahm R., Henning T.
<Astron. Astrophys. 590, A112 (2016)>
=2016A&A...590A.112M 2016A&A...590A.112M (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Planets ; Radial velocities
Keywords: planetary systems - stars: fundamental parameters -
stars: individual: Kepler-539
Abstract:
We confirm the planetary nature of Kepler-539 b (aka Kepler object of
interest K00372.01), a giant transiting exoplanet orbiting a
solar-analogue G2V star. The mass of Kepler-539 b was accurately
derived thanks to a series of precise radial velocity measurements
obtained with the CAFE spectrograph mounted on the CAHA 2.2-m
telescope. A simultaneous fit of the radial-velocity data and Kepler
photometry revealed that Kepler-539 b is a dense Jupiter-like planet
with a mass of Mp=0.97MJup and a radius of Rp=0.747RJup, making
a complete circular revolution around its parent star in 125.6-days.
The semi-major axis of the orbit is roughly 0.5au, implying that the
planet is at 0.45au from the habitable zone. By analysing the
mid-transit times of the 12 transit events of Kepler-539 b recorded by
the Kepler spacecraft, we found a clear modulated transit time
variation (TTV), which is attributable to the presence of a planet c
in a wider orbit. The few timings available do not allow us to
precisely estimate the properties of Kepler-539 c and our analysis
suggests that it has a mass between 1.2 and 3.6 MJup, revolving on a
very eccentric orbit (0.4<e<0.6) with a period larger than 1000-days.
The high eccentricity of planet c is the probable cause of the TTV
modulation of planet b. The analysis of the CAFE spectra revealed a
relatively high photospheric lithium content, A(Li)=2.48dex, which,
together with both a gyrochronological and isochronal analysis,
suggests that the parent star is relatively young.
Description:
Radial velocity measurements of Kepler-539 obtained using the CAFE
spectrograph mounted on the CAHA 2.2-m telescope at the Observatory of
Calar Alto (Spain).
Objects:
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RA (2000) DE Designation(s)
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19 56 29.388 +41 52 00.32 Kepler-539 = 2MASS J19562938+4152003
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
k539_rv.dat 43 20 RVs of Kepler-539 (CAFE/CAHA 2.2-m telescope)
(table 1)
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See also:
J/MNRAS/444/776 : Transiting planets WASP-24, 25 and 26 (Southworth+, 2014)
J/MNRAS/436/2 : Transits of WASP-19b (Mancini+, 2013)
J/A+A/573/L5 : Radial velocity data of Kepler-432 (Ciceri+, 2015)
J/A+A/576/A88 : 8 KOI eclipsing binaries radial velocities (Lillo-Box+, 2015)
J/A+A/580/A63 : HATS-13b and HATS-14b light and RV curves (Mancini+, 2015)
Byte-by-byte Description of file: k539_rv.dat
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Bytes Format Units Label Explanations
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1- 13 F13.7 d BJD Barycentric JD for the midpoint of observation
(BJD-2400000)
16- 21 F6.3 km/s RV Radial velocity of the target
24- 28 F5.3 km/s e_RV Measurement error of the radial velocity
30- 35 F6.3 km/s FWHM CCF FWHM of the spectrum
38- 43 F6.3 km/s BVS CCF bisector velocity span of the spectrum
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Acknowledgements:
Luigi Mancini, mancini(at)mpia.de
Max Planck Institute for Astronomy, Germany
(End) Luigi Mancini [MPIA, Germany], Patricia Vannier [CDS] 26-Apr-2016