J/AJ/151/124 BVR photometry of IZ Mon and AR Dra (Yang+, 2016)
Near-contact binaries IZ Monocerotis and AR Draconis.
Yang Y.-G., Dai H.-F., Zhou Z., Li Q.
<Astron. J., 151, 124-124 (2016)>
=2016AJ....151..124Y 2016AJ....151..124Y (SIMBAD/NED BibCode)
ADC_Keywords: Binaries, eclipsing ; Photometry, UBVRI ; Photometry, CCD
Keywords: binaries: close - binaries: eclipsing -
stars: individual (AR Dra, IZ Mon)
Abstract:
We present multi-color photometric observations for two neglected
near-contact binaries, IZ Mon (P=0.77980d) and AR Dra
(P=0.67584d). By the aid of the updated W-D analysis code, the
photometric solutions were deduced from the multi-color light curves
(LCs). IZ Mon is a semi-detached binary with a mass ratio of
q=0.388(±0.002) , while AR Dra is a detached star with a mass ratio
of q=0.652(±0.002). The asymmetric LCs of IZ Mon were modeled by a
hot spot on the secondary's surface, which may be attributed to mass
transfer from the primary. Based on all collected eclipse times for
two systems, we constructed their timing residual curves. The orbital
period for IZ Mon may be continuously decreasing at a rate of
dP/dt=-2.06(±0.04)days/yr, which may result from mass and angular
momentum loss from the central system. For AR Dra, there exists a
cyclic variation with a period of P3=104.9(±2.9)yr due to
light-time orbit effect via the presence of the third body, whose mass
is more than 0.28(±0.02)M☉. Finally, two near-contact
binaries, IZ Mon and AR Dra, will evolve into contact binaries.
Description:
CCD Photometry for IZ Mon and AR Dra, was acquired using the 60cm
telescope and the 85cm telescope at the Xinglong station (XLs) of
National Astronomical Observatories of China (NAOC). Two telescopes
are equipped with the standard Johnson-Cousins UBVRcIc. filters.
We then obtained the individual observations as heliocentric Julian
dates and differential magnitude, which are listed in Table1.
The complete light curves for IZ Mon were obtained on 2009 January 20,
22, 24, 25, and 26, and March 1, using the 85cm telescope. The
exposure times are fixed to be 20, 15, and 15s for BVR bands,
respectively. A total of 961, 960, and 959 effective images in BVR
bands are obtained. Another primary eclipse for IZ Mon was monitored
on 2011 January 17.
AR Dra was observed on 2009 February 20, 25, 26, and 27, with the 65cm
telescope. The typical exposure times are 50, 40 and 40s for BVR
bands, which depend on the condition of weather. In total, we obtained
733, 728 and 356 images in B, V and R bands, respectively.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 69 1694 Photometric observations for IZ Mon and AR Dra
table2.dat 33 26 New observed light minimum times
table3.dat 47 57 Previously published and new eclipsing times
for IZ Mon
table4.dat 47 124 Previously published and new light minimum
times for AR Dra
table6.dat 88 2 Estimated absolute parameters for IZ Mon and
AR Dra
refs.dat 115 73 References
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See also:
B/vsx : AAVSO International Variable Star Index VSX (Watson+, 2006-2014)
B/gcvs : General Catalogue of Variable Stars (Samus+ 2007-2013)
J/AJ/147/145 : Algol-type binaries. VIII. DI Peg & AF Gem (Yang+, 2014)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- Name Star name (IZ Mon or AR Dra) (1)
8- 20 F13.5 d HJD-B Heliocentric Julian Date of B band data
22- 27 F6.3 mag DBmag [0.5/2.2] Differential Johnson B band
magnitude (2)
29- 41 F13.5 d HJD-V ? Heliocentric Julian Date of V band data
43- 48 F6.3 mag DVmag [0.68/2.1]? Differential Johnson V band
magnitude (2)
50- 62 F13.5 d HJD-R ? Heliocentric Julian Date of R band data
64- 69 F6.3 mag DRmag [0.76/1.98]? Differential Cousins R band
magnitude (2)
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Note (1): The comparison star is:
IZ Mon (table 3) : TYC 748-849-1;
AR Dra (table 4) : TYC 4158-264-1.
Note (2): The 1σ errors for the photometric bands are:
IZ Mon : ±0.008mag in B, ±0.006mag in V , and ±0.005mag in R;
AR Dra : less than 0.007mag in three bands.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- Name Star name (IZ Mon or AR Dra)
8- 20 F13.5 d HJD Heliocentric Julian Date
22- 28 F7.5 d e_HJD Uncertainty in HJD
30- 31 A2 --- Min Minimum type (I or II)
33 A1 --- Flt [BVR] Filter (B, V, or R)
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Byte-by-byte Description of file: table[34].dat
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Bytes Format Units Label Explanations
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1- 12 F12.4 d HJD Heliocentric Julian Date
14- 21 F8.1 --- Epoch [-23848/36691] Epoch
23- 25 A3 --- Meth Observation method (p, pe, pv, vi, or CCD) (1)
27- 28 A2 --- Min Minimum type (I or II)
30- 36 F7.4 --- O-C0 [-0.13/0.054] Initial timing residual (O-C)i (2)
38- 44 F7.4 --- O-C1 [-0.063/0.055] Final timing residual (O-C)f
46- 47 I2 --- Ref [1/73] Reference code; in refs.dat file
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Note (1): The four methods are defined as below:
p = Plate photometry;
pv = Plate photometry;
pe = Photoelectric photometry;
pg = Photographic photometry;
vi = Visual inspection;
CCD = Charge-Coupled Device photometry.
Note (2): Computed by using the ephemeris:
* Min.I=HJD2427344.644+0.7798076*E (Eq. (1)) for IZ Mon;
* Min.I=HJD2442868.9124+0.67583743*E (Eq. (3)) for AR Dra.
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- Name Source name (IZ Mon or AR Dra)
8- 11 F4.2 Rsun Sep [4.19/5.22] Separation between components (a)
13- 16 F4.2 Rsun e_Sep [0.03/0.05] Uncertainty in Sep
18- 21 F4.2 Msun Mass1 [1.31/2.01] Absolute mass of primary
23- 26 F4.2 Msun e_Mass1 [0.03/0.06] Uncertainty in Mass1
28- 31 F4.2 Rsun Rad1 [1.47/2.48] Absolute radius of primary
33- 36 F4.2 Rsun e_Rad1 [0.05/0.13] Uncertainty in Rad1
38- 42 F5.2 Lsun Lum1 [3.58/28.7] Absolute luminosity of primary
44- 47 F4.2 Lsun e_Lum1 [0.24/2.9] Uncertainty in Lum1
49- 52 F4.2 Msun Mass2 [0.78/0.85] Absolute mass of secondary
54- 57 F4.2 Msun e_Mass2 [0.02/0.02] Uncertainty in Mass2
59- 62 F4.2 Rsun Rad2 [1.44/1.49] Absolute radius of secondary
64- 67 F4.2 Rsun e_Rad2 [0.05/0.09] Uncertainty in Rad2
69- 72 F4.2 Lsun Lum2 [1.04/1.22] Absolute luminosity of secondary
74- 77 F4.2 Lsun e_Lum2 [0.07/0.14] Uncertainty in Lum2
79- 88 F10.8 d Per [0.675837/0.779808] Period (from the text)
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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 [1/73] Reference number
4- 22 A19 --- BibCode Bibliographic code
24- 74 A51 --- Aut Author's name
76-115 A40 --- Com Comments
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History:
From electronic version of the journal
(End) Prepared by [AAS]; Sylvain Guehenneux [CDS] 28-Jul-2016