J/ApJ/791/54 Nearby M Dwarfs parameters (Gaidos+, 2014)
M dwarf metallicities and giant planet occurrence: ironing out uncertainties
and systematics.
Gaidos E., Mann A.W.
<Astrophys. J., 791, 54 (2014)>
=2014ApJ...791...54G 2014ApJ...791...54G (SIMBAD/NED BibCode)
ADC_Keywords: Stars, M-type ; Stars, dwarfs ; Abundances, [Fe/H] ;
Effective temperatures ; Stars, masses ; Stars, diameters
Keywords: planets and satellites: formation -
planets and satellites: gaseous planets - stars: abundances -
stars: fundamental parameters - stars: low-mass -
techniques: spectroscopic
Abstract:
Comparisons between the planet populations around solar-type stars and
those orbiting M dwarfs shed light on the possible dependence of
planet formation and evolution on stellar mass. However, such analyses
must control for other factors, i.e., metallicity, a stellar parameter
that strongly influences the occurrence of gas giant planets. We
obtained infrared spectra of 121 M dwarfs stars monitored by the
California Planet Search and determined metallicities with an accuracy
of 0.08 dex. The mean and standard deviation of the sample are -0.05
and 0.20 dex, respectively. We parameterized the metallicity
dependence of the occurrence of giant planets on orbits with a period
less than two years around solar-type stars and applied this to our M
dwarf sample to estimate the expected number of giant planets. The
number of detected planets (3) is lower than the predicted number
(6.4), but the difference is not very significant (12% probability of
finding as many or fewer planets). The three M dwarf planet hosts are
not especially metal rich and the most likely value of the power-law
index relating planet occurrence to metallicity is 1.06 dex per dex
for M dwarfs compared to 1.80 for solar-type stars; this difference,
however, is comparable to uncertainties. Giant planet occurrence
around both types of stars allows, but does not necessarily require, a
mass dependence of ∼1 dex per dex. The actual planet-mass-metallicity
relation may be complex, and elucidating it will require larger
surveys like those to be conducted by ground-based infrared
spectrographs and the Gaia space astrometry mission.
Description:
Using the SpeX spectrograph (Rayner et al. 2003PASP..115..362R 2003PASP..115..362R) on the
NASA Infrared Telescope (IRTF), we obtained simultaneous JHK spectra
of 121 of the 147 stars in the Rauscher & Marcy (2006PASP..118..617R 2006PASP..118..617R,
hereafter RM06) catalog of M dwarfs monitored by the CPS. Observations
were carried out between 2011 September and 2013 December and targets
were selected entirely based on visibility from Maunakea, i.e.,
without regard to their properties or whether they host known planets.
We used SpeX in the cross-dispersed (SXD) mode and the 0.3 arcsec
slit, which yielded simultaneous coverage from 0.8 to 2.4 um at a
resolution λ/δλ of about 2000. Targets were nodded
between two positions along the slit (A and B) to ensure accurate sky
subtraction. At least six exposures were taken of each target
following the ABBA nodding pattern. Exposure times are capped at 120 s
to mitigate errors from atmospheric variation, although most exposure
times were much shorter (typically 10-20 s).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 86 131 Parameters of Nearby M Dwarfs from the
California Planet Search
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See also:
I/239 : The Hipparcos and Tycho Catalogues (ESA 1997)
J/MNRAS/389/585 : Fundamental parameters of M dwarfs (Casagrande+, 2008)
J/A+A/551/A36 : Metallicity of M dwarfs. III. (Neves+, 2013)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 14 A14 --- Star Star name
16- 21 I6 --- HIP ?=0 Hipparcos catalog number
(NNNNNN in cat I/239)
23- 27 F5.2 [-] [Fe/H] ?=99.99 Metallicity
29- 32 F4.2 [-] e_[Fe/H] ?=0 Error in [Fe/H]
34- 37 I4 K Teff Effective temperature
39- 41 I3 K e_Teff Error in Teff
43 A1 --- l_Rad Upper limit flag on Rad
44- 47 F4.2 Rsun Rad Radius
49- 52 F4.2 Rsun e_Rad ?=0 Error in Rad; 0 for upper limits
54 A1 --- l_Lum Upper limit flag on Lum
55- 60 F6.4 Lsun Lum Luminosity
62- 67 F6.4 Lsun e_Lum ?=0 Error in Lum; 0 for upper limits
69 A1 --- l_Mass Upper limit flag on Mass
70- 73 F4.2 Msun Mass Mass
75- 78 F4.2 Msun e_Mass ?=0 Error in Mass; 0 for upper limits
80- 86 A7 --- STeff Source of effective temperature
(Visible or K-band)
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History:
From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 27-Mar-2017