J/AJ/147/148 Spectroscopy and photometry of AP And (Lacy+, 2014)
Absolute properties of the eclipsing binary star AP Andromedae.
Lacy C.H.S., Torres G., Fekel F.C., Muterspaugh M.W.
<Astron. J., 147, 148 (2014)>
=2014AJ....147..148L 2014AJ....147..148L
ADC_Keywords: Binaries, eclipsing ; Radial velocities ; Photometry, CCD
Keywords: binaries: eclipsing - binaries: spectroscopic -
stars: fundamental parameters - stars: individual: AP And
Abstract:
AP And is a well-detached F5 eclipsing binary star for which only a
very limited amount of information was available before this
publication. We have obtained very extensive measurements of the light
curve (19097 differential V magnitude observations) and a radial
velocity curve (83 spectroscopic observations) which allow us to fit
orbits and determine the absolute properties of the components very
accurately: masses of 1.277±0.004 and 1.251±0.004M☉, radii
of 1.233±0.006 and 1.1953±0.005R☉, and temperatures of
6565±150K and 6495±150K. The distance to the system is about
400±30pc. Comparison with the theoretical properties of the stellar
evolutionary models of the Yonsei-Yale series of Yi et al. shows good
agreement between the observations and the theory at an age of about
500 Myr and a slightly sub-solar metallicity.
Description:
AP And was monitored spectroscopically with three different
instruments over more than 9yr. Observations began at the
Harvard-Smithsonian CfA with the 1.5m telescope at the F. L. Whipple
Observatory (Mount Hopkins, AZ). A single echelle order 45Å wide
centered at about 5187Å (MgI b triplet) was recorded with an
intensified photon-counting Reticon detector (digital speedometer,
DS), with a resolving power of approximately R=35000. A total of 16
spectra were collected between 2004 January and 2008 October.
Additional observations were gathered on the same telescope using the
bench-mounted Tillinghast Reflector Echelle Spectrograph (TRES), from
2009 October to 2013 January. The resolving power of this instrument
is R=44000, and the wavelength coverage is 3900-9100Å.
A further 41 echelle spectrograms of AP And were collected from 2011
October to 2013 October using the Tennessee State University 2m
telescope and a fiber fed echelle spectrograph. The detector was a
Fairchild 486 CCD. The resulting echelle spectrograms have 48 orders
and have a wavelength coverage of 3800-8260Å. We used a fiber that
produced a resolving power of 15000 at 6000Å.
Sets of V-band differential photometry were obtained from images taken
by two independent robotic telescopes, the URSA WebScope at the
University of Arkansas campus and the NFO WebScope near Silver City,
NM, USA. The URSA WebScope is constructed from a 10inch diameter f/6.3
Meade LX200 Schimdt-Cassegrain telescope with an SBIG ST8 CCD camera,
inside a Technical Innovations Robo-Dome. The NFO WebScope is
constructed from a Group 128 24 inch diameter classical Cassegrain
telescope with a Kodak KAF 4300E CCD camera. Both telescopes used
Bessel V filters. The star was observed with URSA from 2003 July 11 to
2012 July 13 and with the NFO from 2004 December 17 to 2013 December
2.
Objects:
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RA (ICRS) DE Designation(s) (Period)
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23 49 30.71 +45 47 21.3 AP And = TYC 3639-915-1 (P=1.587291156)
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File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 33 135 Observed dates of minimum light for AP And
table2.dat 52 83 Heliocentric radial velocities for AP And
table4.dat 26 7895 V-band differential photometry (variable-comps)
of AP And from the URSA WebScope (at Kimpel
Observatory, Arkansas)
table5.dat 26 11209 V-band differential photometry (variable-comps)
of AP And from the NFO WebScope (near Silver
City, New Mexico)
refs.dat 81 20 References
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See also:
B/gcvs : General Catalogue of Variable Stars (Samus+ 2007-2013)
J/AJ/147/1 : Spectroscopy and photometry of HP Aur (Lacy+, 2014)
J/AJ/142/185 : Properties of the eclipsing binary stars HY Vir (Lacy+, 2011)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 11 F11.5 d HJD Heliocentric Julian Date (HJD-2400000)
13 I1 --- Type Eclipse type (1 or 2) (1)
15- 21 F7.5 d e_HJD Uncertainty in HJD
23- 30 F8.5 d O-C The (O-C) residual
32- 33 I2 --- Ref Reference; in refs.dat file
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Note (1): Eclipses of type 1 are the deeper eclipses when the hotter, more
massive star (star A) is being eclipsed by the cooler, less massive
star (star B).
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- Inst Facility/Instrument used (1)
10- 19 F10.4 d HJD Heliocentric Julian Date (HJD-2400000)
21- 27 F7.2 km/s RVA Radial velocity of A component
29- 35 F7.2 km/s RVB Radial velocity of B component
37- 40 F4.2 km/s e_RVA ? Uncertainty in RVA
42- 45 F4.2 km/s e_RVB ? Uncertainty in RVB
47- 52 F6.4 --- Phase Phase (2)
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Note (1): Instruments used are defined as follows:
CfA/DS = Harvard-Smithsonian Center for Astrophysics/Digital Speedometer;
CfA/TRES = Harvard-Smithsonian Center for Astrophysics/Tillinghast Reflector
Echelle Spectrograph;
FAIRBORN = A robotic telescope at Fairborn Observatory.
Note (2): Based on the ephemeris in Section 2.
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Byte-by-byte Description of file: table[45].dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 F7.5 --- Phase Orbital phase (1)
9- 14 F6.3 mag DVmag Differential V band magnitude
16- 26 F11.5 d HJD Heliocentric Julian Date (HJD-2400000)
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Note (1): The orbital phase has been computed from the photometric values in
Equation (1): HJD MinI=2454717.65759(2)+1.587291156(33)E.
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Ref Reference number
4- 22 A19 --- BibCode Bibliographic code
24- 40 A17 --- Aut Author's name
42- 81 A40 --- Com Comments
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Sylvain Guehenneux [CDS] 07-Oct-2014