J/AJ/146/79 Differential BVRI light curves of EP And (Liao+, 2013)
The multi-color light curves of the W UMa type contact binary EP Andromedae.
Liao W.-P., Qian S.-B., Li K., He J.-J., Zhao E.-G., Zhou X.
<Astron. J., 146, 79 (2013)>
=2013AJ....146...79L 2013AJ....146...79L
ADC_Keywords: Binaries, eclipsing ; Photometry, UBVRI
Keywords: binaries: close - binaries: eclipsing - stars: individual: EP And
Abstract:
New multi-color CCD photometric light curves of the eclipsing binary
EP And were obtained over six nights in 2006, 2011, and 2012. Using
the Wilson-Devinney code, we computed the photometric elements of this
system. It was discovered that EP And is a W-type W UMa contact binary
system with a mass ratio of q=2.685 and a degree of contact factor
f=24.9%, rather than an A-type system. Combining 28 newly determined
times of minimum light derived from 1999 to 2012 with others collected
from the literature, a long-term increase (dP/dt=+5.22x10-8days/yr)
with a sinusoidal variation (A=0.0109days; T=40.89yr) in the orbital
period was found. The orbital period secular increases may be
interpreted as conservative mass transfer from the less massive
component to the more massive one, and cyclic variations of the
orbital period may be caused by the light-travel time effect through
the presence of a third body. The evolutionary status and the age of
the system are also discussed.
Description:
Using the PI 1024 TKB CCD photometric system attached to the 1.0m
Cassegrain reflecting telescope at the Yunnan Observatory in China, we
performed B-, V-, and R-band observations for EP And on 2006 January
22, 23, and 30. The Johnson BVR filters were used. We reobserved the
star (with BVRI filters) on three consecutive nights (2011 December 30
and 31, and 2012 January 1) with the DW 436 2048*2048 CCD photometric
system attached to the same telescope at the Yunnan Observatory.
Objects:
----------------------------------------------------------------------------
RA (ICRS) DE Designation(s) (Period)
----------------------------------------------------------------------------
01 42 29.32 +44 45 42.4 EP Andromedae = GSC 02827-00017 (P=0.40410869)
----------------------------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2a.dat 36 205 BVR observations for the eclipsing binary
EP And observed in 2006
table2b.dat 36 733 BVRI observations for the eclipsing binary
EP And observed in 2011 and 2012
--------------------------------------------------------------------------------
See also:
B/gcvs : General Catalogue of Variable Stars (Samus+ 2007-2013)
V/119 : Catalogue of field contact binary stars (Pribulla+, 2003)
J/AJ/145/100 : Differential BVR light curves of EP And (Lee+, 2013)
Byte-by-byte Description of file: table2[ab].dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 A1 --- Flt [BVRI] Filter used in the observation (BVRI)
3- 15 A13 --- Year Year(s) the observations were obtained
17- 29 F13.5 d HJD Heliocentric Julian Date of the observation
31- 36 F6.3 mag dmag Differential magnitude in Flt
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Sylvain Guehenneux [CDS] 10-Jul-2014