J/ApJ/768/L12 Abundances in host stars XO-2S and XO-2N (Teske+, 2013)
Carbon and oxygen abundances in the hot Jupiter exoplanet host star XO-2B and
its binary companion.
Teske J.K., Schuler S.C., Cunha K., Smith V.V., Griffith C.A.
<Astrophys. J., 768, L12 (2013)>
=2013ApJ...768L..12T 2013ApJ...768L..12T
ADC_Keywords: Abundances ; Equivalent widths ; Stars, double and multiple ;
Planets
Keywords: planets and satellites: formation; stars: atmospheres;
planets and satellites: individual: XO-2; stars: abundances
Abstract:
With the aim of connecting the compositions of stars and planets, we
present the abundances of carbon and oxygen, as well as iron and
nickel, for the transiting exoplanet host star XO-2N and its
wide-separation binary companion XO-2S. Stellar parameters are derived
from high-resolution, high signal-to-noise spectra, and the two stars
are found to be similar in their Teff, log g, iron ([Fe/H]), and
nickel ([Ni/H]) abundances. Their carbon ([C/H]) and oxygen ([O/H])
abundances also overlap within errors, although XO-2N may be slightly
more C-rich and O-rich than XO-2S. The C/O ratios of both stars
(∼0.60±0.20) may also be somewhat larger than solar (C/O∼0.50).
The XO-2 system has a transiting hot Jupiter orbiting one binary
component but not the other, allowing us to probe the potential
effects planet formation might have on the host star composition.
Additionally, with multiple observations of its atmosphere the
transiting exoplanet XO-2b lends itself to compositional analysis,
which can be compared to the natal chemical environment established by
our binary star elemental abundances. This work sets the stage for
determining how similar or different exoplanet and host star
compositions are, and the implications for planet formation, by
discussing the C/O ratio measurements in the unique environment of a
visual binary system with one star hosting a transiting hot Jupiter.
Description:
Observations of XO-2N and XO-2S were conducted during two half-nights,
2012 February 10 and 11 (UT), with the 8.2m Subaru Telescope using the
High Dispersion Spectrograph. Spectra of the Sun (as reflected
moonlight) were taken the first night. Wavelength coverage of the
spectra is ∼4450-5660Å and ∼5860-7100Å with R∼60000.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 56 87 Lines measured, equivalent widths, and abundances
stars.dat 121 2 Derived stellar parameters (from table2)
--------------------------------------------------------------------------------
See also:
J/AJ/146/76 : Astrometry and phot. of UCAC4 double stars (Hartkopf+, 2013)
J/other/Nat/486.375 : Stellar parameters of KOI stars (Buchhave+, 2012)
J/ApJ/757/161 : Spectroscopy of 56 exoplanet host stars (Torres+, 2012)
J/ApJ/737/L32 : Abundances of 16 Cyg A and B (Schuler+, 2011)
J/ApJ/735/41 : Carbon and oxygen abundances in FGK stars (Petigura+, 2011)
J/ApJ/732/55 : Abundances of stars with planets (Schuler+, 2011)
J/ApJ/725/2349 : C/O vs Mg/Si of planetary systems (Delgado Mena+, 2010)
J/ApJ/720/1592 : Abundances of solar analogs with planets (Hernandez+, 2010)
J/ApJ/720/1290 : Abundances of stars hosting planets (Ghezzi+, 2010)
J/ApJ/715/1050 : Predicted abundances for extrasolar planets. I. (Bond+, 2010)
J/A+A/508/L17 : Abundances in solar analogs (Ramirez+, 2009)
J/PASJ/57/65 : CNO abundances of solar-type stars (Takeda+, 2005)
J/ApJ/622/1102 : The planet-metallicity correlation. (Fischer+, 2005)
J/A+A/415/1153 : [Fe/H] for 98 extra-solar planet-host stars (Santos+, 2004)
J/A+A/402/343 : IR OI triplet, [O I] lines in F-K dwarfs/giants (Takeda, 2003)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- Ion Ion
7- 13 F7.2 0.1nm lambda [4620.5/7114.6] Wavelength in Angstroms
15- 18 F4.2 eV ExPot [0/7.7] Excitation potential
20- 24 F5.2 [-] log(gf) [-9.8/-0.2] Log of the oscillator strength
26- 29 F4.1 10-13m EWS Equivalent width in the solar spectrum (2)(1)
31- 34 F4.2 [-] logNS Log of solar number abundance (2)
36- 40 F5.1 10-13m EWXO-2S ? Equivalent width in the XO-2S spectrum (1)
42- 45 F4.2 [-] logNXO-2S ? Log of XO-2S number abundance
47- 51 F5.1 10-13m EWXO-2N ? Equivalent width in the XO-2N spectrum (1)
53- 56 F4.2 [-] logNXO-2N ? Log of XO-2N number abundance
--------------------------------------------------------------------------------
Note (1): In units of milli-Angstroms.
Note (2): Adopted solar parameters: Teff=5777K, logg=4.44, and Vt=1.38km/s.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: stars.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- Name Star name
7- 10 I4 K Teff [5343/5547] Effective temperature
12- 13 I2 K e_Teff Teff uncertainty
15- 18 I4 K Teff2 Effective temperature from B07 (1)
20- 21 I2 K e_Teff2 Teff2 uncertainty (1)
23- 26 F4.2 [cm/s2] logg [4.2/4.5] Log of surface gravity
28- 31 F4.2 [cm/s2] e_logg logg uncertainty
33- 36 F4.2 [cm/s2] logg2 Surface gravity from B07 (1)
38- 41 F4.2 [cm/s2] e_logg2 logg2 uncertainty (1)
43- 46 F4.2 km/s Vt [1.2/1.3] Turbulent velocity
48- 51 F4.2 km/s e_Vt [0.07/0.09] Vt uncertainty
53- 56 F4.2 [Sun] [Fe/H] [0.2/0.4] Metallicity
58- 61 F4.2 [Sun] e_[Fe/H] Uncertainty of [Fe/H]
63- 66 F4.2 [Sun] [Fe/H]2 Abundance of [Fe/H] from B07 (1)
68- 71 F4.2 [Sun] e_[Fe/H]2 Uncertainty of [Fe/H]2 (1)
73- 76 F4.2 [Sun] [C/H] [0.2/0.5] Abundance of [C/H]
78- 81 F4.2 [Sun] e_[C/H] Uncertainty of [C/H]
83- 86 F4.2 [Sun] [Ni/H] [0.3/0.5] Abundance of [Ni/H]
88- 91 F4.2 [Sun] e_[Ni/H] Uncertainty of [Ni/H]
93- 96 F4.2 [Sun] [Ni/H]2 Abundance of [Ni/H] from B07 (1)
98-101 F4.2 [Sun] e_[Ni/H]2 Uncertainty of [Ni/H]2 (1)
103-106 F4.2 [Sun] [O/H] [0.1/0.4] Abundance of [O/H]
108-111 F4.2 [Sun] e_[O/H] Uncertainty of [O/H]
113-116 F4.2 [Sun] C/O [0.6] C/O abundance ratio
118-121 F4.2 [Sun] e_C/O C/O uncertainty
--------------------------------------------------------------------------------
Note (1): B07 = Burke et al. 2007ApJ...671.2115B 2007ApJ...671.2115B
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 28-Nov-2014