J/ApJ/946/61 Hydra sp. obs. of K2 planet-host stars (Loaiza-Tacuri+, 2023)
A spectroscopic analysis of a sample of K2 planet-host stars: stellar
parameters, metallicities and planetary radii.
Loaiza-Tacuri V., Cunha K., Smith V.V., Martinez C.F., Ghezzi L.,
Schuler S.C., Teske J., Howell S.B.
<Astrophys. J., 946, 61 (2023)>
=2023ApJ...946...61L 2023ApJ...946...61L
ADC_Keywords: Abundances; Effective temperatures; Spectra, optical;
Stars, diameters; Stars, masses; Exoplanets
Keywords: Fundamental parameters of stars ; Spectroscopy ; Exoplanet systems ;
F stars ; G stars ; K stars
Abstract:
The physical properties of transiting exoplanets are connected with
the physical properties of their host stars. We present a homogeneous
spectroscopic analysis based on the spectra of FGK-type stars observed
with the Hydra spectrograph on the WIYN telescope. We derived the
effective temperatures, surface gravities, and metallicities, for
81 stars observed by K2 and 33 by Kepler 1. We constructed an FeI and
FeII line list that is adequate for the analysis of R∼18000 spectra
covering 6050-6350Å and adopted the spectroscopic technique based
on equivalent-width measurements. The calculations were done in LTE
using Kurucz model atmospheres and the qoyllur-quipu (q2) package.
We validated our methodology via an analysis of a benchmark solar twin
and solar proxies, which are used as a solar reference. We estimated
the effects that including Zeeman-sensitive FeI lines have on the
derived stellar parameters for young and possibly active stars in our
sample and found them not to be significant. Stellar masses and radii
were derived by combining the stellar parameters with Gaia EDR3 and V
magnitudes and isochrones. The measured stellar radii have a 4.2%
median internal precision, leading to a median internal uncertainty of
4.4% in the derived planetary radii. With our sample of 83 confirmed
planets orbiting K2 host stars, the radius gap near
Rplanet∼1.9R⊕ is detected, in agreement with previous
findings. Relations between the planetary radius, orbital period, and
metallicity are explored and these also confirm previous findings for
Kepler 1 systems.
Description:
The spectra analyzed in this study were obtained in several observing
runs targeting stars from the Ecliptic Plane Input Catalog (EPIC) for
the K2 mission and, as a lower priority, Kepler objects of interest
(KOI) from the Kepler 1 mission. The observing runs took place between
2015 and 2019 using the Hydra multifiber spectrograph (R∼18500)
mounted on the WIYN 3.5m telescope at Kitt Peak.
The total number of K2 stars analyzed is 81 (69 stars with confirmed
planets and 12 stars with candidate planets) and it includes stars
from campaigns C0, C1, C3-C6, C8, and C10 (some stars from C5 were
also observed in C16 and C18).
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 86 115 Main sample data
table3.dat 76 115 Stellar parameters, radii and masses
table6.dat 50 139 Planetary radii
--------------------------------------------------------------------------------
See also:
V/133 : Kepler Input Catalog (Kepler Mission Team, 2009)
IV/34 : K2 Ecliptic Plane Input Catalog (EPIC) (Huber+, 2017)
I/347 : Distances to 1.33 billion stars in Gaia DR2 (Bailer-Jones+, 2018)
IV/38 : TESS Input Catalog - v8.0 (TIC-8) (Stassun+, 2019)
I/350 : Gaia EDR3 (Gaia Collaboration, 2020)
III/284 : APOGEE-2 data from DR16 (Johnsson+, 2020)
I/352 : Distances to 1.47 billion stars in Gaia EDR3 (Bailer-Jones+, 2021)
J/A+AS/141/371 : Low-mass stars isochrones (Girardi+, 2000)
J/A+A/415/1153 : [Fe/H] for 98 extra-solar planet-host stars (Santos+, 2004)
J/ApJ/622/1102 : The planet-metallicity correlation. (Fischer+, 2005)
J/A+A/508/L17 : Abundances in solar analogs (Ramirez+, 2009)
J/AJ/142/160 : Kepler Mission. II. EBs in DR2 (Slawson+, 2011)
J/A+A/533/A141 : Stellar parameters for 582 HARPS FGK stars (Sousa+, 2011)
J/other/Nat/486.375 : Stellar parameters of KOI stars (Buchhave+, 2012)
J/ApJS/204/24 : Kepler planetary candidates. III. (Batalha+, 2013)
J/ApJ/771/40 : Main-sequence A, F, G, and K stars phot. (Boyajian+, 2013)
J/ApJ/771/107 : Spectroscopy of faint KOI stars (Everett+, 2013)
J/ApJ/764/78 : Oxygen abundances in nearby FGK stars (Ramirez+, 2013)
J/A+A/562/A71 : Abundances of solar neighbourhood dwarfs (Bensby+, 2014)
J/ApJ/791/14 : 18 Sco atomic data and equivalent widths (Melendez+, 2014)
J/MNRAS/445/2758 : KIC giants Bayesian dist. and extinctions (Rodrigues+ 2014)
J/A+A/579/A19 : K2 Variable Catalogue (Armstrong+, 2015)
J/ApJ/808/187 : Metallicities of KIC stars without planets (Buchhave+, 2015)
J/MNRAS/452/3561 : Kepler EB stars. K2 Campaign 0 (LaCourse+, 2015)
J/ApJ/809/25 : Stellar and planet data for K2 candidates (Montet+, 2015)
J/ApJS/217/31 : Kepler planetary cand. VI. 4yr Q1-Q16 (Mullally+, 2015)
J/ApJ/815/5 : Abundances of KOI stars with planets. I. (Schuler+, 2015)
J/A+A/594/A100 : K2 new planetary and EB candidates (Barros+, 2016)
J/ApJS/225/32 : Extended abundance analysis of cool stars (Brewer+, 2016)
J/ApJS/226/7 : Planets discovered using K2's 1st yr (Crossfield+, 2016)
J/ApJS/224/2 : K2 EPIC stellar properties for 138600 targets (Huber+, 2016)
J/MNRAS/463/1780 : Exoplanet candidates in Praesepe (M 44) (Libralato+, 2016)
J/AJ/152/187 : Planet occurrence & metallicity for KOIs (Mulders+, 2016)
J/ApJS/222/14 : Planetary cand. from 1st yr K2 mission (Vanderburg+, 2016)
J/ApJ/835/173 : Kepler asteroseismic LEGACY set. II. (Silva Aguirre+, 2017)
J/AJ/153/71 : Kepler follow-up obs. program. I. Imaging (Furlan+, 2017)
J/ApJ/844/102 : KIC star plx from asteroseismology vs Gaia (Huber+, 2017)
J/AJ/154/224 : Transiting planets in clusters from K2 (Rizzuto+, 2017)
J/ApJS/233/23 : APOKASC cat. of KIC dwarfs and subgiants (Serenelli+, 2017)
J/ApJ/866/99 : Radii of KIC stars & planets using Gaia DR2 (Berger+, 2018)
J/ApJS/237/38 : Extended abundance analysis of KOIs (Brewer+, 2018)
J/ApJS/239/5 : Variable stars and cand. planets from K2 (Crossfield+, 2018)
J/A+A/619/A97 : CoRoT transit catalogue (Deleuil+, 2018)
J/AJ/156/264 : California-Kepler Survey (CKS). VII. (Fulton+, 2018)
J/ApJ/860/109 : Keck HIRES obs. of 245 subgiants (Ghezzi+, 2018)
J/AJ/156/277 : Planets from K2 campaigns 5-8 (Livingston+, 2018)
J/A+A/619/A73 : Solar Twins activity (Lorenzo-Oliveira+, 2018)
J/AJ/155/136 : Planets orbiting bright stars in K2 C0-10 (Mayo+, 2018)
J/AJ/155/21 : Planet candidates from K2 campaigns 5-8 (Petigura+, 2018)
J/ApJS/239/32 : APOKASC-2 cat. of Kepler evolved stars (Pinsonneault+, 2018)
J/ApJS/235/38 : Kepler planetary cand. VIII. (Thompson+, 2018)
J/AJ/155/68 : Elemental abundances of KOIs in APOGEE. I. (Wilson+, 2018)
J/ApJS/238/30 : LAMOST obs. in Kepler field. II. 5yrs LRS sp. (Zong+, 2018)
J/ApJS/244/11 : Planet candidates and EBs in K2 campaigns 0-8 (Kruse+, 2019)
J/AJ/160/108 : Gaia-Kepler stellar properties cat. II. (Berger+, 2020)
J/AJ/159/211 : Exoplanets parameters from Kepler and K2 (Cloutier+, 2020)
J/ApJS/247/28 : K2 star param. from Gaia & LAMOST (Hardegree-Ullman+, 2020)
J/ApJ/895/52 : EW and abundances in 211 stars with HARPS (Spina+, 2020)
J/MNRAS/496/851 : Planet candidates from K2 Campaigns 1-13 (Wittenmyer+, 2020)
J/MNRAS/506/150 : The GALAH+ Survey DR3 (Buder+, 2021)
J/ApJ/920/19 : Spectroscopic analysis of CKS. II. (Ghezzi+, 2021)
J/AJ/161/164 : Obs. of 186 TESS stars with NESSI (WYIN) (Howell+, 2021)
J/AJ/162/75 : Speckle obs. TESS exoplanet host stars. II. (Lester+, 2021)
J/AJ/162/259 : Scaling K2. IV. C1-8 & 10-18 planets sample (Zink+, 2021)
J/MNRAS/514/4300 : Late-type dwarfs logR'HK and magnetic fields (Brown+, 2022)
J/MNRAS/510/2041 : Planetary systems study with GALAH surveys (Clark+, 2022)
J/AJ/163/179 : The California-Kepler Survey. X. (Petigura+, 2022)
J/ApJS/261/26 : Host stars from LAMOST, TESS, Kepler & K2 (Su+, 2022)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 --- ID Star identifier
15- 27 A13 --- OName Host other name
29- 32 I4 yr Obs.Y [2015/2019] Year of the observation
34- 36 A3 "month" Obs.M Month of the observation
38- 39 I2 d Obs.D Day of the observation
41- 42 I2 h RAh Hour of Right Ascension (J2000)
44- 45 I2 min RAm Minute of Right Ascension (J2000)
47- 51 F5.2 s RAs Second of Right Ascension (J2000)
53- 53 A1 --- DE- Sign of the Declination (J2000)
54- 55 I2 deg DEd Degree of Declination (J2000)
57- 58 I2 arcmin DEm Arcminute of Declination (J2000)
60- 64 F5.2 arcsec DEs Arcsecond of Declination (J2000)
66- 70 F5.2 mag Vmag [8.87/14.8] Apparent V band magnitude from the
NASA Exoplanet Archive
72- 82 A11 s Exp Exposure time per spectrum
84- 86 I3 --- S/N [50/255] Signal-to-Noise of the reduced spectra
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 --- ID Star identifier as in Table 1
15- 18 I4 K Teff [4296/6365] Effective temperature
20- 22 I3 K e_Teff [56/307] Uncertainty in Teff
24- 27 F4.2 [cm/s2] log(g) [3/4.8] log surface gravity
28- 29 A2 --- f_log(g) Flag on log(g) (1)
31- 34 F4.2 [cm/s2] e_log(g) [0.1/0.6] Uncertainty in log(g)
36- 39 F4.2 [-] A(Fe) [7/8] The iron abundance; log(N(Fe)/N(H))+12
41- 44 F4.2 [-] e_A(Fe) [0.05/0.3] Uncertainty in A(Fe)
46- 49 F4.2 km/s VTurb [0.5/1.9] Microturbulent velocity
51- 54 F4.2 km/s e_VTurb [0.1/0.5] Uncertainty in VTurb
56- 59 F4.2 Rsun Rs [0.6/4.1] Stellar radius
60 A1 --- f_Rs Flag on Rs (2)
62- 65 F4.2 Rsun e_Rs [0.01/1.4] Uncertainty in Rs
67- 70 F4.2 Msun Ms [0.67/1.5] Stellar mass
71 A1 --- f_Ms Flag on Ms (2)
73- 76 F4.2 Msun e_Ms [0.02/0.4] Uncertainty in Ms
--------------------------------------------------------------------------------
Note (1): Flag as follows:
* = Asteroseismic log(g);
** = no measureable Fe II lines;
Note (2): Flag as follows:
a = Rs/Ms computed using log(g) values.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 --- ID Star identifier
16- 31 A16 --- Planet Planet name
33- 39 F7.1 ppm DeltaF [44.3/19011] Transit depth, ΔF (1)
41- 45 F5.2 Rgeo Rp [0.56/13.9] Planetary radius
47- 50 F4.2 Rgeo e_Rp [0.02/1.1] Uncertainty in Rp
--------------------------------------------------------------------------------
Note (1): Collected from Kruse+ 2019, J/ApJS/244/11 and where available for
K2 planets, while for Kepler 1 planets from Thompson+ 2018, J/ApJS/235/38.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 27-Feb-2025