J/ApJ/797/31 The G+M eclipsing binary V530 Orionis photometry (Torres+, 2014)
The G+M eclipsing binary V530 Orionis: a stringent test of magnetic stellar
evolution models for low-mass stars.
Torres G., Lacy C.H.S., Pavlovski K., Feiden G.A., Sabby J.A., Bruntt H.,
Clausen J.V.
<Astrophys. J., 797, 31 (2014)>
=2014ApJ...797...31T 2014ApJ...797...31T (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Binaries, eclipsing ;
Radial velocities ; Photometry, uvby
Keywords: binaries: eclipsing - stars: evolution -
stars: fundamental parameters - stars: individual: V530 Ori -
techniques: photometric
Abstract:
We report extensive photometric and spectroscopic observations of the
6.1 day period, G+M-type detached double-lined eclipsing binary V530 Ori,
an important new benchmark system for testing stellar evolution
models for low-mass stars. We determine accurate masses and radii for
the components with errors of 0.7% and 1.3%, as follows:
MA=1.0038±0.0066 M☉, MB=0.5955±0.0022 M☉,
RA=0.980±0.013 R☉, and RB=0.5873±0.0067 R☉. The
effective temperatures are 5890±100 K (G1 V) and 3880±120 K (M1 V),
respectively. A detailed chemical analysis probing more than 20
elements in the primary spectrum shows the system to have a slightly
subsolar abundance, with [Fe/H]=-0.12±0.08. A comparison with theory
reveals that standard models underpredict the radius and overpredict
the temperature of the secondary, as has been found previously for
other M dwarfs. On the other hand, models from the Dartmouth series
incorporating magnetic fields are able to match the observations of
the secondary star at the same age as the primary (∼3 Gyr) with a
surface field strength of 2.1±0.4 kG when using a rotational dynamo
prescription, or 1.3±0.4 kG with a turbulent dynamo approach, not
far from our empirical estimate for this star of 0.83±0.65 kG. The
observations are most consistent with magnetic fields playing only a
small role in changing the global properties of the primary. The V530 Ori
system thus provides an important demonstration that recent advances
in modeling appear to be on the right track to explain the long-standing
problem of radius inflation and temperature suppression in low-mass stars.
Description:
V530 Ori was monitored spectroscopically with three different
instruments over a period of more than 17 yr. Observations began at
the Harvard-Smithsonian Center for Astrophysics (CfA) in 1996 June
with a Cassegrain-mounted echelle spectrograph ("Digital Speedometer",
DS; Latham 1992ASPC...32..110L 1992ASPC...32..110L) attached to the 1.5 m Tillinghast
reflector at the F. L. Whipple Observatory (Mount Hopkins, AZ). We
gathered a further 30 spectra of V530 Ori at the Kitt Peak National
Observatory (KPNO) from 1999 March to 2001 January, using the coude-feed
telescope and the coude spectrometer. Finally, 41 additional
observations were obtained at the CfA from 2009 November to 2014 March
with the Tillinghast Reflector Echelle Spectrograph (TRES; Furesz 2008,
PhD thesis , Univ. Szeged, Hungary) on the 1.5 m telescope mentioned
earlier. Two sets of V-band images of V530 Ori were obtained with
independent robotic telescopes operating at the University of Arkansas
(URSA WebScope) and near Silver City, NM (NFO WebScope) from 2001 January
to 2012 February. Differential photometric measurements of V530 Ori
were also gathered with the Stromgren Automatic Telescope at ESO (La Silla,
Chile), during several campaigns from 2001 January to 2006 February.
Objects:
-----------------------------------------------------
RA (ICRS) DE Designation(s)
-----------------------------------------------------
06 04 33.8 -03 11 52 V530 Ori = V* V530 Ori
-----------------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 47 41 Times of eclipse for V530 Ori
table2.dat 50 143 Heliocentric radial velocity measurements of
V530 Ori
table6.dat 24 5137 Differential V-band measurements of V530 Ori
from URSA
table7.dat 24 3024 Differential V-band measurements of V530 Ori
from NFO
table8.dat 42 720 Differential uvby measurements of V530 Ori
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See also:
V/118 : Catalog of eclipsing binaries parameters (Perevozkina+, 1999)
J/A+AS/131/395 : Eclipsing binaries light curves models (Claret 1998)
J/A+A/487/1081 : uvby photometry of 6 eclipsing binaries (Clausen+, 2008)
J/A+A/387/850 : Radial velocities of eclipsing binaries (Imbert, 2002)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 F9.4 yr Obs.Y Year of the observation
11- 20 F10.4 d HJD Heliocentric Julian Date (HJD-2400000)
22- 27 F6.4 d sigma ? Timing uncertainty (1)
29- 32 I4 --- Epoch Cycle number (2)
34 I1 --- Ecl [1/2] Eclipse type (3)
36- 41 F6.4 d O-C The (O-C) residuals
43- 44 A2 --- Type Observation type (4)
46- 47 I2 --- Source [1/12] Source (5)
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Note (1): As published, or as measured in the case of our own photometric
observations. Adopted uncertainties for the photographic, visual, and
photoelectric/CCD measurements with no published errors are 0.028,
0.011, and 0.0001 days, respectively. Other errors have been scaled
by iterations during the ephemeris fit by factors of 1.8 and 2.9 for
the primary and secondary (see text).
Note (2): Counted from the reference time of primary eclipse (see text).
Note (3): Eclipse type as follows:
1 = primary;
2 = secondary.
Note (4): Type as follows:
PG = photographic;
V = visual;
PE = photoelectric or CCD measurement.
Note (5): Source as follows:
1 = Strohmeier (1959, VeBam, 5, 3);
2 = Isles (1988, Brit. Astr. Soc. Circ., 67, 11);
3 = Lacy & Fox (1994IBVS.4009....1L 1994IBVS.4009....1L);
4 = Lacy et al. (1999IBVS.4737....1L 1999IBVS.4737....1L);
5 = This paper;
6 = Lacy (2002AJ....124.1162L 2002AJ....124.1162L);
7 = Lacy (2004IBVS.5577....1L 2004IBVS.5577....1L);
8 = Lacy (2007IBVS.5764....1L 2007IBVS.5764....1L);
9 = Nagai (2008, Var. Star Bull. (Japan), 46, 5);
10 = Diethelm (2009IBVS.5894....1D 2009IBVS.5894....1D);
11 = Lacy (2011IBVS.5972....1L 2011IBVS.5972....1L);
12 = Diethelm (2011IBVS.5992....1D 2011IBVS.5992....1D).
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Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 F10.4 d HJD Heliocentric Julian Date; (HJD-2400000)
12- 17 F6.4 --- Phase Orbital phase
19- 24 F6.2 km/s RVA Primary radial velocity
26- 32 F7.2 km/s RVB Secondary radial velocity
34- 38 F5.2 km/s (O-C)A Primary (O-C) residual
40- 45 F6.2 km/s (O-C)B Secondary (O-C) residual
47- 50 A4 --- Inst Instrument used (1)
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Note (1): Instrument as follows:
DS = Digital Speedometer;
KPNO = Kitt Peak National Observatory coude-feed telescope and
the coude spectrometer;
TRES = Tillinghast Reflector Echelle Spectrograph.
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Byte-by-byte Description of file: table6.dat table7.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 F11.5 d HJD Heliocentric Julian Date (HJD-2400000)
13- 18 F6.4 --- Phase Phase (G1)
20- 24 F5.3 mag DelVmag Differential V band magnitude
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Byte-by-byte Description of file: table8.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 F11.5 d HJD Heliocentric Julian Date (HJD-2400000)
13- 18 F6.4 --- Phase Phase (G1)
20- 24 F5.3 mag Delumag Differential u band magnitude
26- 30 F5.3 mag Delvmag Differential v band magnitude
32- 36 F5.3 mag Delbmag Differential b band magnitude
38- 42 F5.3 mag Delymag Differential y band magnitude
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Global notes:
Note (G1): Phase counted from the reference epoch of primary eclipse
given in Section 2.
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History:
* 22-Aug-2017 : From electronic version of the journal
* 19-Sep-2017 : Corrected table2 with minus signs from author
(Guillermo Torres, gtorres(at)cfa.harvard.edu)
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 14-Aug-2017