J/MNRAS/437/2831 4 transiting F-M binary systems (Zhou+, 2014)
The mass-radius relationship for very low mass stars:
four new discoveries from the HATSouth Survey.
Zhou G., Bayliss D., Hartman J.D., Bakos G.A., Penev K., Csubry Z.,
Tan T.G., Jordan A., Mancini L., Rabus M., Brahm R., Espinoza N.,
Mohler-Fischer M., Ciceri S., Suc V., Csak B., Henning T., Schmidt B.
<Mon. Not. R. Astron. Soc., 437, 2831-2844 (2014)>
=2014MNRAS.437.2831Z 2014MNRAS.437.2831Z (SIMBAD/NED BibCode)
ADC_Keywords: Binaries, eclipsing ; Photometry, SDSS ; Radial velocities
Keywords: binaries: eclipsing - stars: low-mass
Abstract:
We report the discovery of four transiting F-M binary systems with
companions between 0.1 and 0.2M☉ in mass by the HATSouth survey.
These systems have been characterized via a global analysis of the
HATSouth discovery data, combined with high-resolution radial
velocities and accurate transit photometry observations. We determined
the masses and radii of the component stars using a combination of two
methods: isochrone fitting of spectroscopic primary star parameters
and equating spectroscopic primary star rotation velocity with
spin-orbit synchronization. These new very low mass companions are
HATS550-016B (0.110-0.006+0.005M☉, 0.147-0.004+0.003R☉),
HATS551-019B (0.17-0.01+0.01Msun, 0.18-0.01+0.01R☉),
HATS551-021B (0.132-0.005+0.014Msun, 0.154-0.008+0.006R☉)
and HATS553-001B (0.20-0.02+0.01Msun, 0.22-0.01+0.01R☉).
We examine our sample in the context of the radius anomaly for fully
convective low-mass stars. Combining our sample with the 13 other
well-studied very low mass stars, we find a tentative 5 percent
systematic deviation between the measured radii and theoretical
isochrone models.
Description:
The transiting VLMS systems were identified from photometric
observations by the HATSouth global network. HATSouth consists of six
telescope units spread over three sites, SSO in Australia, LCO in
Chile and the HESS site in Namibia, providing continuous monitoring of
128deg2 fields in the southern sky.
Radial velocity measurements derived from high-resolution
spectroscopic observations were obtained for the VLMS systems using
the Echelle spectrograph on the ANU 2.3m telescope at SSO, the
fibre-fed echelle spectrograph CORALIE on the Swiss Leonard Euler 1.2m
telescope at La Silla Observatory (LSO), Chile, and the fibre-fed
echelle spectrograph FEROS on the MPG/ESO 2.2m telescope at LSO.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
stars.dat 68 4 List of studied stars
tablea1.dat 38 9631 g'r'i'z' differential photometry for HATS550-016
tablea2.dat 38 6420 r'Rc differential photometry for HATS551-019
tablea3.dat 38 5274 r' differential photometry for HATS551-021
tablea4.dat 38 10795 r'Rc differential photometry for HATS553-001
tablea5.dat 46 14 Radial velocities for HATS550-016
tablea6.dat 46 10 Radial velocities for HATS551-019
tablea7.dat 46 12 Radial velocities for HATS551-021
tablea8.dat 46 6 Radial velocities for HATS553-001
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Byte-by-byte Description of file: stars.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Name Star name
13- 14 I2 h RAh Right ascension (J2000)
16- 17 I2 min RAm Right ascension (J2000)
19- 23 F5.2 s RAs Right ascension (J2000)
25 A1 --- DE- Declination sign (J2000)
26- 27 I2 deg DEd Declination (J2000)
29- 30 I2 arcmin DEm Declination (J2000)
32- 35 F4.1 arcsec DEs Declination (J2000)
37- 44 F8.6 d Per Period (from table 4)
46- 56 A11 --- Phot Name of the table with photometry
58- 68 A11 --- RV Name of the table with radial velocities
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Byte-by-byte Description of file: tablea[1234].dat
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Bytes Format Units Label Explanations
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1- 12 F12.6 d BJD Barycentric Julian date (BJD-2400000)
14- 20 F7.5 --- Flux Differential flux
22- 28 F7.5 --- e_Flux rms uncertainty on Flux
30- 35 A6 --- Inst Instrument
37- 38 A2 --- Filt [griz' Rc] Filter
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Byte-by-byte Description of file: tablea[5678].dat
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Bytes Format Units Label Explanations
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1- 12 F12.6 d BJD Barycentric Julian date (BJD-2400000)
16- 20 F5.2 km/s RV Radial velocity
24- 27 F4.2 km/s e_RV rms uncertainty on RV
32- 46 A15 --- Inst Instrument
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 10-Mar-2015