J/AJ/143/13 Light curves of AL Gem and BM Mon (Yang+, 2012)
Photometric properties of selected algol-type binaries.
III. AL Geminorum and BM Monocerotis with possible light-time orbits.
Yang Y.-G., Li H.-L., Dai H.-F.
<Astron. J., 143, 13 (2012)>
=2012AJ....143...13Y 2012AJ....143...13Y
ADC_Keywords: Binaries, eclipsing ; Photometry, VRI ; Photometry, CCD
Keywords: binaries: close - binaries: eclipsing -
stars: individual (AL Gem, BM Mon)
Abstract:
We present the CCD photometry of two Algol-type binaries, AL Gem and
BM Mon, observed from 2008 November to 2011 January. With the updated
Wilson-Devinney program, photometric solutions were deduced from their
EA-type light curves. The mass ratios and fill-out factors of the
primaries are found to be qph=0.090(±0.005) and
f1=47.3%(±0.3%) for AL Gem, and qph=0.275(±0.007) and
f1=55.4%(±0.5%) for BM Mon, respectively. By analyzing the O-C
curves, we discovered that the periods of AL Gem and BM Mon change in
a quasi-sinusoidal mode, which may possibly result from the light-time
effect via the presence of a third body. Periods, amplitudes, and
eccentricities of light-time orbits are 77.83(±1.17)yr,
0.0204(±0.0007)d, and 0.28(±0.02) for AL Gem and 97.78(±2.67)yr,
0.0175(±0.0006)d, and 0.29(±0.02) for BM Mon, respectively.
Assumed to be in a coplanar orbit with the binary, the masses of the
third bodies would be 0.29M☉ for AL Gem and 0.26M☉ for BM
Mon. This kind of additional companion can extract angular momentum
from the close binary orbit, and such processes may play an important
role in multiple star evolution.
Description:
CCD photometry of AL Gem and BM Mon was carried out from 2008 November
to 2011 January, using the 60cm telescope at the Xinglong Station of
National Astronomical Observatories of China (NAOC). The standard
Johnson-Cousin-Bessel set of UBVRcIc filters was used.
Photometric observations (1438 and 1427 images in V and R bands) of
AL Gem were performed on eight nights in 2008 November and December
(table2). Another primary eclipse of AL Gem was taken on 2010 December
10, using the 85cm telescope at the Xinglong station of NAOC.
The multi-color photometry of BM Mon was carried out on seven nights
in 2010 December and 2011 January. A total of 750 observations in the
V band and 748 ones in the R band were obtained (table2). An
additional primary eclipse of BM Mon was observed by an AAVSO
(American Astronomical Variable Star Observers) observer in 2011.
For AL Gem, with four new eclipse times, we compiled a total of 125
light minimum times (14 plate, 10 photographic, 71 visual, 5
photoelectric, and 25 CCD), which is spread over 107yr from 1903 to
2010. For BM Mon, the compiled eclipse times (representing 2 plate
cases, 38 visual, 31 photographic, 1 photoelectric, and 19 CCD) span
over 116yr from 1895 to 2011.
Objects:
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RA (2000) DE Designation(s) (Period)
---------------------------------------------------------------------
06 57 38.55 +20 53 32.5 AL Gem = HD 266913 (P=1.39134001)
07 08 45.28 +00 41 46.1 BM Mon = GSC 00163-02281 (P=1.24494386)
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File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2a.dat 39 1438 VR photometric observations of AL Gem
table2b.dat 39 750 VR photometric observations of BM Mon
table4.dat 47 125 All compiled light minimum times of the
eclipsing binary AL Gem
table6.dat 47 91 All collected light minimum times of the
eclipsing binary BM Mon
refs.dat 138 84 References
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See also:
B/gcvs : General Catalogue of Variable Stars (Samus+ 2007-2012)
B/vsx : AAVSO International Variable Star Index VSX (Watson+, 2006-2013)
J/AJ/106/2096 : Limb-darkening coefficients in binaries (Van Hamme 1993)
J/AJ/117/587 : Apsidal motion in double stars. I. (Petrova+, 1999)
J/other/IBVS/5493 : 2003 CCD minima of eclipsing binaries (Nelson+, 2004)
J/other/IBVS/5543 : 163-nd list of minima of EBs (Diethelm, 2004)
J/AcA/54/207 : Ephemerids of eclipsing binaries (Kreiner, 2004)
J/A+A/417/263 : Catalogue of Algol type binary stars (Budding+, 2004)
J/other/IBVS/5592 : Eclipsing binary stars photoelectric minima (Krajci+, 2005)
J/A+A/446/785 : Catalogue of eclipsing variables (Malkov+, 2006)
J/MNRAS/378/179 : EBs with eccentric orbits catalog (Bulut+, 2007)
J/other/IBVS/5802 : Minima and maxima of 735 variables (Hubscher+, 2007)
J/AJ/137/226 : Differential light curves of TV Tri - Paper I (Yang+, 2009)
J/AJ/139/1360 : AO Ser VR light curves - Paper II (Yang+, 2010)
J/other/IBVS/5918 : Minima and maxima of 452 variables (Hubscher+, 2010)
J/other/JAVSO/38.183 : Time of minima of eclipsing binaries (Samolyk+, 2010)
J/other/IBVS/5984 : Minima and maxima of 503 variables (Hubscher, 2011)
Byte-by-byte Description of file: table2[ab].dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 F12.4 d HJD-V AL Gem V band Heliocentric Julian Date
14- 19 F6.3 mag DVmag AL Gem differential V band magnitude
21- 32 F12.4 d HJD-R ? AL Gem R band Heliocentric Julian Date
34- 39 F6.3 mag DRmag ? AL Gem differential R band magnitude
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Byte-by-byte Description of file: table[46].dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 F12.4 d HJD Heliocentric Julian Date
14- 21 F8.1 --- Epoch Epoch in cycles
23- 25 A3 --- Meth Detection method (CCD, pe, p, vi or pg) (1)
27- 28 A2 --- Min Minimum type (I or II)
30- 36 F7.4 mag O-C The (O-C) value (2)
38- 44 F7.4 mag Res ? Residual of the fit
46- 47 I2 --- Ref [1/84] Reference, in refs.dat file
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Note (1): Method as follows:
CCD = CCD measurements
pe = photometric measurements
p = plate data
pg = photographic data
vi = visual data
Note (2): O-C residuals for all light minimum times (computed using a
linear ephemeris given by Kreiner et al. 2001
(http://www.as.up.krakow.pl/o-c). See equation (1) for
table4 and equation (4) for table6 in the paper.
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Byte-by-byte Description of file: refs.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- Ref [1/84] Reference number
4- 22 A19 --- BibCode Bibliographic code
24- 44 A21 --- Aut Author's name
46-138 A93 --- Com Comments
--------------------------------------------------------------------------------
History:
From electronic version of the journal
References:
Yang & Wei Paper I 2009AJ....137..226Y 2009AJ....137..226Y Cat. J/AJ/137/226
Yang et al. Paper II 2010AJ....139.1360Y 2010AJ....139.1360Y Cat. J/AJ/139/1360
Yang et al. Paper IV 2012AJ....144...50Y 2012AJ....144...50Y Cat. J/AJ/144/50
Yang et al. Paper V 2012AJ....144..136Y 2012AJ....144..136Y Cat. J/AJ/144/136
Yang et al. Paper VI 2014AJ....147...35Y 2014AJ....147...35Y Cat. J/AJ/147/35
Zhang et al. Paper VII 2014AJ....147...66Z 2014AJ....147...66Z Cat. J/AJ/147/66
Yang et al. Paper VIII 2014AJ....147..145Y 2014AJ....147..145Y Cat. J/AJ/147/145
Yang et al. Paper IX 2016AJ....152...49Y 2016AJ....152...49Y Cat. J/AJ/152/49
(End) Greg Schwarz [AAS], Sylvain Guehenneux [CDS] 04-Apr-2013