J/A+A/625/A150 10 very-low-mass stars photometry (von Boetticher+, 2019)
The EBLM V. Physical Properties of ten fully convective, very-low-mass stars.
von Boetticher A., Triaud A.H.M.J., Queloz D., Gill S., Maxted P.F.L.,
Almleaky Y., Anderson D. R., Bouchy F., Burdanov A., Collier Cameron A.,
Delrez L., Ducrot E., Faedi F., Gillon M., Gomez Maqueo Chew Y., Hebb L.,
Hellier C., Jehin E., Lendl M., Marmier M., Martin D.V., McCormac J.,
Pepe F., Pollacco D., Segransan D., Smalley B., Thompson S., Turner O.,
Udry S., Van Grootel V., West R.
<Astron. Astrophys. 625, A150 (2019)>
=2019A&A...625A.150V 2019A&A...625A.150V (SIMBAD/NED BibCode)
ADC_Keywords: Binaries, eclipsing ; Photometry
Keywords: stars: low-mass - binaries: eclipsing - binaries: spectroscopic -
techniques: spectroscopic - techniques: photometric
Abstract:
Measurements of the physical properties of stars at the lower end of
the main sequence are scarce. In this context we report masses, radii
and surface gravities of ten very-low-mass stars in eclipsing binary
systems, with orbital periods of the order of several days. The
objects probe the stellar mass-radius relation in the fully convective
regime, M*<0.35M☉, down to the hydrogen burning mass-limit,
MHB∼0.07M☉. The stars were detected by the WASP survey for
transiting extra-solar planets, as low-mass, eclipsing companions
orbiting more massive, F- and G-type host stars. We use eclipse
observations of the host stars, performed with the TRAPPIST, Leonhard
Euler and SPECULOOS telescopes, and radial velocities of the host
stars obtained with the CORALIE spectrograph, to determine the
physical properties of the low-mass companions. Surface gravities of
the low-mass companions are derived from the eclipse and orbital
parameters of each system. Spectroscopic measurements of the host star
effective temperature and metallicity are used to infer the host star
mass and age from stellar evolution models for solar-type stars.
Masses and radii of the low-mass companions are then derived from the
eclipse and orbital parameters of the binary systems. The objects are
compared to stellar evolution models for low-mass stars, to test for
an effect of the stellar metallicity and orbital period on the radius
of low-mass stars in close binary systems. Measurements are found to
be in good agreement with stellar evolution models; a systematic
inflation of the radius of low-mass stars with respect to model
predictions is limited to 1.6±1.2%, in the fully convective low-mass
regime. The sample of ten objects indicates a scaling of the radius of
low-mass stars with the host star metallicity. No correlation between
stellar radii and the orbital periods of the binary systems is
determined. A combined analysis with thirteen comparable objects from
the literature is consistent with this result.
Description:
Eclipse measurements with the TRAPPIST, Leonhard Euler, and SPECULOOS
telescopes are provided. For two objects, the WASP discovery
light-curve is also provided, to better constrain the eclipse
duration. Radial velocities measured with the CORALIE spectrograph are
provided. For one object, HARPS radial velocities are also provided.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 91 10 Coordinates, magnitudes, and parallax
measurements of the host stars
coralie.dat 132 215 Coralie and HARPS radial velocities
trap1.dat 250 4253 Trappist eclipse observations for J0543-57,
J0555-57, J0954-23, J1013+01 and J1431-11
trap2.dat 211 1243 Trappist eclipse observations for J0339+03,
J1115-36 and J2017+02 and Euler J0555-57,
J1038-37 and J1403-32
euler.dat 101 902 Euler eclipse observations for J0555-57,
J1038-37 and J1403-32
j1115was.dat 39 61320 J1115-36 WASP light curve
j2017was.dat 39 13470 J2017+02 WASP light curve
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Name Name (JHHMM+DDA)
11- 12 I2 h RAh Right ascension (ICRS) at epoch 2015.5
14- 15 I2 min RAm Right ascension (ICRS) at epoch 2015.5
17- 21 F5.2 s RAs Right ascension (ICRS) at epoch 2015.5
23 A1 --- DE- Declination sign (ICRS) at epoch 2015.5
24- 25 I2 deg DEd Declination (ICRS) at epoch 2015.5
27- 28 I2 arcmin DEm Declination (ICRS) at epoch 2015.5
30- 33 F4.1 arcsec DEs Declination (ICRS) at epoch 2015.5
35- 39 F5.2 mag Gmag Gaia DR2 G magnitude
40 A1 --- n_Gmag [*] Note on Gmag (1)
42- 45 F4.2 mas Plx Gaia DR2 absolute parallax
47- 50 F4.2 mas e_Plx rms uncertainty on Plx
52- 58 A7 --- Coralie Indicates coralie observations in
coralie.dat file
60- 64 A5 --- Harps Indicates Harps observations in
coralie.dat file
66- 70 A5 --- Trappist Indicates Trappist observations in
trap1.dat or trap2.dat files
72- 76 A5 --- Euler Indicates Euler observations in euler.dat file
78- 86 A9 --- Speculoos Indicates Speculoos observations in
trap1.dat file
88- 91 A4 --- WASP Indicates WASP observations in
J1115-36-wasp.dat and J2017+02-wasp.dat files
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Note (1): Note as follows:
* = EBLM J0555-57AB is a visual binary system, where J0555-57A is itself
a spectroscopic binary
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Byte-by-byte Description of file: coralie.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Name Star name (JHHMM+DD)
10- 17 A8 --- Inst Instrument
19- 30 F12.6 d BJD Barycentric Julian date (BJD-240000)
32- 40 F9.5 km/s RV Radial velocity
42- 48 F7.5 km/s e_RV rms uncertainty on RV
50- 58 F9.5 km/s FWHM FWHM
60- 65 F6.3 km/s Contrast Contrast of the cross-correlation function
67- 80 F14.5 km/s BIS Bisector span
82- 88 F7.5 km/s Noise Noise
90- 94 F5.2 --- sn10 Signal-to-noise ratio 10
96-100 F5.2 --- sn50 Signal-to-noise ratio 50
102-106 F5.2 --- sn60 Signal-to-noise ratio 60
107-132 A26 --- Com Comments
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Byte-by-byte Description of file: trap1.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Name Star name (JHHMM+DD), EBLM JHHMM+DD
10- 17 A8 --- Inst Instrument
19- 36 F18.13 d JD Julian date (JD-2450000), UTC
38- 56 F19.17 ct Flux Flux
58- 80 E23.18 ct e_Flux rms uncertainty on Flux
82-105 E24.19 pix xshift Centroid x_shift on detector
107-130 E24.19 pix yshift Centroid y_shift on detector
132-149 F18.16 pix FWHMx FWHM on x axis
151-169 F19.16 pix FWHMy FWHM on y axis
171-190 F20.16 pix FWHM FWHM
192-211 F20.16 ct Sky Sky
213-230 F18.16 --- Airmass Airmass
232-250 F19.16 s Exptime Exposure time
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Byte-by-byte Description of file: trap2.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Name Star name (JHHMM+DD)
10- 17 A8 --- Inst Instrument
19- 36 F18.13 d HJD Heliocentric Julian date (HJD-2400000)
38- 56 F19.17 ct Flux Flux
58- 80 E23.18 ct e_Flux rms uncertainty on Flux
82-105 E24.19 pix dX Centroid x_shift on detector
107-130 E24.19 pix dY Centroid x_shift on detector
132-149 F18.16 --- Airmass Airmass
151-169 F19.16 pix FWHM FWHM
171-190 F20.16 ct Sky Sky
192-211 F20.16 s Texp Exposure time
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Byte-by-byte Description of file: euler.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Name Star name (JHHMM+DD)
10- 14 A5 --- Inst Instrument
16- 27 F12.6 d HJD Heilocentric Julian date (HJD-2400000)
30- 37 F8.6 ct Flux Flux
40- 47 F8.6 ct e_Flux rms uncertainty on Flux
49- 54 F6.2 pix dX Centroid x_shift on detector
57- 61 F5.2 pix dY Centroid y_shift on detector
64- 67 F4.2 --- Airmass Airmass
69- 73 F5.2 pix FWHM FWHM
76- 82 F7.2 ct Sky Sky
85- 92 F8.2 ct SkyMax ? Maximum value for sky
96-101 F6.2 s Texp Exposure time
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Byte-by-byte Description of file (#): j1115was.dat j2017was.dat
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Bytes Format Units Label Explanations
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3- 15 F13.8 d HJD Heliocentric Julian date (HJD-2450000)
19- 27 F9.6 mag dmag Tamuz-corrected magnitude
32- 39 F8.6 mag e_dmag rms uncertainty on dmag
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Acknowledgements:
Alexander von Boetticher, alexander.vonboetticher(at)merton.ox.ac.uk
(End) A. von Boetticher [University of Oxford], P. Vannier [CDS] 23-Apr-2019