J/AJ/162/211 APF radial velocity follow up of ι Draconis (Hill+, 2021)
Asteroseismology of iota Draconis and discovery of an additional long-period
companion.
Hill M.L., Kane S.R., Campante T.L., Li Z., Dalba P.A., Brandt T.D.,
White T.R., Pope B.J.S., Stassun K.G., Fulton B.J., Corsaro E., Li T.,
Ong J.M.J., Bedding T.R., Bossini D., Buzasi D.L., Chaplin W.J.,
Cunha M.S., Garcia R.A., Breton S.N., Hon M., Huber D., Jiang C.,
Kayhan C., Kuszlewicz J.S., Mathur S., Serenelli A., Stello D.
<Astron. J., 162, 211-211 (2021)>
=2021AJ....162..211H 2021AJ....162..211H (SIMBAD/NED BibCode)
ADC_Keywords: Exoplanets; Stars, K-type; Radial velocities; Optical
Keywords: Photometry; Radial velocity; Exoplanet dynamics; Exoplanets
Exoplanet astronomy; Exoplanet systems; Exoplanet detection methods
Planet hosting stars; Asteroseismology; Stellar astronomy
Planetary dynamics; Detection
Abstract:
Giant stars as known exoplanet hosts are relatively rare due to the
potential challenges in acquiring precision radial velocities and the
small predicted transit depths. However, these giant host stars are
also some of the brightest in the sky and so enable high
signal-to-noise ratio follow-up measurements. Here, we report on new
observations of the bright (V∼3.3) giant star ιDraconis
(ιDra), known to host a planet in a highly eccentric ∼511 day
period orbit. TESS observations of the star over 137days reveal
asteroseismic signatures, allowing us to constrain the stellar radius,
mass, and age to ∼2%, ∼6%, and ∼28%, respectively. We present the
results of continued radial-velocity monitoring of the star using the
Automated Planet Finder over several orbits of the planet. We provide
more precise planet parameters of the known planet and, through the
combination of our radial-velocity measurements with Hipparcos and
Gaia astrometry, we discover an additional long-period companion with
an orbital period of ∼68-36+60yr. Mass predictions from our
analysis place this substellar companion on the border of the planet
and brown dwarf regimes. The bright nature of the star combined with
the revised orbital architecture of the system provides an opportunity
to study planetary orbital dynamics that evolve as the star moves into
the giant phase of its evolution.
Description:
456 radial velocity observations were obtained by the Levy
spectrometer on the Automated Planet Finder (APF) at Lick Observatory
from 2018 February to 2021 February.
Objects:
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RA (2000) DE Designation(s) (Period)
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15 24 55.77 +58 57 57.8 iota Draconis = * iot Dra (P=510.855d)
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 42 456 Radial Velocity Observations of ιDra
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See also:
III/150 : Perkins Revised MK Types for the Cooler Stars (Keenan+ 1989)
I/311 : Hipparcos, the New Reduction (van Leeuwen, 2007)
I/337 : Gaia DR1 (Gaia Collaboration, 2016)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/ApJ/757/161 : Spectroscopy of 56 exoplanet host stars (Torres+, 2012)
J/A+A/566/A113 : Radial velocity curves of HIP105854 (Jones+, 2014)
J/A+A/574/A50 : Chemical abundances of giants and subgiants (Jofre+, 2015)
J/A+A/574/A116 : G and K giant stars stellar parameters (Reffert+, 2015)
J/A+A/580/A23 : Stroemgren-Crawford uvbyβ photometry cat. (Paunzen, 2015)
J/A+A/588/A87 : Seismic global parameters of 6111 KIC (Vrard+, 2016)
J/AJ/152/180 : Bolometric fluxes of eclipsing bin in Tycho-2 (Stassun+, 2016)
J/AJ/153/136 : Planets & their host stars Gaia parallaxes (Stassun+, 2017)
J/MNRAS/469/4578 : Deep learning classification asteroseismology (Hon+, 2017)
J/AJ/155/120 : RV variability of the K-giant γ Draconis (Hatzes+, 2018)
J/AJ/156/102 : TESS Input Catalog and Candidate Target List (Stassun+, 2018)
J/ApJ/858/28 : Mixing-length parameter for sample of KIC stars (Viani+, 2018)
J/AJ/158/13 : The first 300 stars observed by the GPIES (Nielsen+, 2019)
J/AJ/158/181 : Radial velocities and S-index values for HR 5183 (Blunt+, 2019)
J/AJ/158/227 : Asteroseismic parameters of RGB stars (Grunblatt+, 2019)
J/PASP/131/C4401 : TESS predicted yield of transits (Dalba+, 2019)
J/AJ/159/235 : Radial Velocity jitters in ∼600 planet host stars (Luhn+, 2020)
J/AJ/159/241 : TESS-Keck Survey. I. HD332231 Radial Velocities (Dalba+, 2020)
J/ApJS/254/42 : Hipparcos-Gaia (EDR3) Catalog of Accelerations (Brandt, 2021)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 11 F11.3 d BJD [2458156/2459254] Barycentric Julian Date at TDB
13- 26 F14.9 m/s RVel [-250/390] Radial velocity
28- 38 F11.9 m/s e_RVel [1/8] Uncertainty in RVel
40- 42 A3 --- Tel Telescope; AFP
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 13-Jan-2022