J/AJ/149/30 BVRI differential photometry of V1001 Cas in 2012 (Samec+, 2015)
Comparing the precision 2009 and 2012 light curves of the precontact W UMa
binary V1001 Cassiopeia.
Samec R.G., Koenke S.S., Faulkner D.R.
<Astron. J., 149, 30 (2015)>
=2015AJ....149...30S 2015AJ....149...30S
ADC_Keywords: Binaries, eclipsing ; Photometry, UBVRI
Keywords: binaries: close - binaries: eclipsing - stars: evolution -
stars: individual: V1001 Cas
Abstract:
A 2012 follow up to the analysis of 2009 observations is presented for
the very short period (∼0.43days) precontact W UMa binary (PCWB) V1001
Cassiopeia. Its short period, similar to the majority of W UMa
binaries, and its distinct EA light curve make it a very rare and
interesting system for continuing photometric investigation. Previous
photometric VRI standard magnitudes give a K4 spectral type. Our
solutions of light curves separated by some three years give
approximately the same physical parameters. However, the spots have
radically changed in temperature, area, and position. While only one
dark spot was used to model the first curves, two hot spots are now
needed. This affects the overall shape of the light curve, especially
in the secondary eclipses in B and V. Additional eclipse timings now
show that the orbital period is changing. We conclude that spots are
very active on this solar-type dwarf system and that it may mimic its
larger cousins, the RS CVn binaries. The conclusion is that analysis
now needs to be directed at the continuous time evolution of PCWBs.
Description:
V1001 Cas was discovered by Seiichi Yoshida of the MISAO Project
(Nakajima et al., 2005IBVS.5600....1. 2005IBVS.5600....1.). Observational data are
available at http://www.aerith.net/misao/data/misv.cgi?1222. Samec et
al. (2012Obs...132....7S 2012Obs...132....7S; Paper I) reported on observations and
analyses of the 2009 September CCD light curves.
Our present B, V, Rc, Ic light curves were taken with the same
Lowell 31inch reflector in Flagstaff, AZ with a CRYOTIGER cooled
(-100°C) NASACAM and a 2K*2K chip and standard BVRcIc
Johnson-Cousins filters. They were taken on 2012 September 23, 25, and
30, on NURO (National Undergraduate Research Observatory) awarded
time.
Objects:
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RA (ICRS) DE Designation(s) (Period)
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23 50 17.08 +51 11 28.9 V* V1001 Cas = GSC 03651-00655 (P=0.429058)
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 14 877 Photometry of V1001 Cas
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See also:
B/gcvs : General Catalogue of Variable Stars (Samus+ 2007-2013)
J/AJ/142/117 : UBVrcIc differential photometry of V1853 Ori (Samec+, 2011)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1 A1 --- Band Observed band (Johnson-Cousins BVRI)
3- 7 F5.3 mag Dmag Delta magnitude in filter (in the sense of
variable minus comparison star)
9- 14 F6.3 d HJD Heliocentric Julian Date (HJD-2456190)
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History:
From electronic version of the journal
References:
Samec et al., Paper I, 2012Obs...132....7S 2012Obs...132....7S
(End) Greg Schwarz [AAS], Sylvain Guehenneux [CDS] 03-Feb-2015