J/AJ/157/87 Times of minima for 21 early-type SMC eccentric EBs (Zasche+, 2019)
Apsidal motion and absolute parameters of 21 early-type Small Magellanic Cloud
eccentric eclipsing binaries.
Zasche P., Wolf M.
<Astron. J., 157, 87 (2019)>
=2019AJ....157...87Z 2019AJ....157...87Z (SIMBAD/NED BibCode)
ADC_Keywords: Magellanic Clouds ; Binaries, eclipsing ; Stars, early-type ;
Photometry, UBVRI ; Spectral types ; Stars, diameters
Keywords: binaries: eclipsing - Magellanic Clouds - stars: early-type -
stars: fundamental parameters
Abstract:
We present the apsidal motion and light-curve analyses of 21 eccentric
eclipsing binaries located in the Small Magellanic Cloud. Most of these
systems have never been studied before, hence their orbital and physical
properties as well as the apsidal motion parameters are given here for
the first time. All the systems are of early spectral type, having orbital
periods up to 4 days. The apsidal motion periods were derived to be from
7.2 to 200 yr (OGLE-SMC-ECL-2194 having the shortest apsidal period among
known main-sequence systems). The orbital eccentricities are usually
rather mild (median of about 0.06), the maximum eccentricity being 0.33.
For the period analysis using O-C diagrams of eclipse timings, in total
951 minima were derived from survey photometry as well as our new data.
Moreover, six systems show some additional variation in their O-C diagrams,
which should indicate the presence of hidden additional components in them.
According to our analysis these third-body variations have periods
from 6.9 to 22 yr.
Description:
Data for extragalactic binaries became available over the last two or
three decades. This is mainly due to large photometric surveys like
MACHO (Alcock et al. 1997ApJ...486..697A 1997ApJ...486..697A, covering the period 1992-2000),
and OGLE (Udalski et al. 1992AcA....42..253U 1992AcA....42..253U, OGLE II covering 1997-2000,
OGLE III 2001-2009, and OGLE IV 2010-2014) for both Magellanic Clouds.
These surveys harvested a huge portion of eclipsing binaries, 6143 from
MACHO (Faccioli et al. 2007, J/AJ/134/1963), and 48605 from OGLE
(Pawlak et al. 2016, J/AcA/66/421). There are also many eccentric binaries
with noticeable apsidal motion among these systems.
The huge majority of the targets presented in this study belong to three
groups. The first group, consisting of five targets, contains objects
which were already known to have eccentric orbits and have already been
studied. However, we collected many new observations of these systems
during the time span 2012-2018, hence we believe our analysis is better
and more complete than those already published. The second group comprises
stars which were only by-chance discoveries in these monitored fields of
the stars from the first group and are also eccentric with apsidal motion.
Finally, eight systems were found by scanning the OGLE III database
systematically (star numbers 1-1000). For all of these systems we tried
to find all available data, i.e., photometry from MACHO, OGLE, and our
new data from the 1.54 m Danish telescope located at La Silla Observatory
in Chile (hereafter DK154), equipped with a CCD camera, and using I and
R filters (operated remotely from the Czech Republic).
The individual sources of information (MACHO, OGLE, and our new Danish
1.54 m photometry) use different photometric filters, namely B, R, and I
(the OGLE V data were not used owing to much better OGLE I data, both
in quality and quantity).
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 103 21 Relevant information for the analyzed systems
table3.dat 168 21 Parameters of the light-curve fits and
the apsidal motion
table1.dat 51 951 Heliocentric times of minima used for analysis
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See also:
II/236 : UBVR CCD survey of the Magellanic clouds (Massey+, 2002)
J/AcA/48/563 : BVI photometry of OGLE SMC eclipsing binaries
(Udalski+, 1998)
J/AJ/123/855 : Magellanic Clouds Photometric Survey: the SMC
(Zaritsky+, 2002)
J/MNRAS/331/609 : Catalogue of eclipsing binaries in the SMC (Bayne+, 2002)
J/AcA/54/1 : OGLE II SMC eclipsing binaries (Wyrzykowski+, 2004)
J/MNRAS/353/601 : 2dF survey of the Small Magellanic Cloud (Evans+, 2004)
J/AJ/134/1963 : MACHO r,b light curves of MC eclipsing binaries
(Faccioli+, 2007)
J/AcA/63/323 : OGLE-III SMC eclipsing binary stars (Pawlak+, 2013)
J/A+A/572/A71 : Times of minima for 18 SMC eclipsing binaries (Zasche, 2014)
J/ApJ/780/59 : The Araucaria project: eclipsing binaries in SMC
(Graczyk+, 2014)
J/AJ/150/1 : Eclipse timings of 27 eclipsing binaries in the SMC
(Hong+, 2015)
J/AcA/66/421 : Eclipsing binaries in the Magellanic System (Pawlak+, 2016)
J/MNRAS/460/650 : Apsidal motions of 90 SMC eccentric binaries (Hong+, 2016)
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 A17 --- OGLE-III OGLE III system name (OGLE SMC-ECL-NNNNN
in Simbad)
19- 32 A14 --- OGLE-II OGLE II system name (OGLE SMC-SCNN NNNNNN
in Simbad)
34- 47 A14 --- MACHO MACHO system name (MACHO FFF.NNNNN.NNNN
in Simbad)
49- 50 I2 h RAh Hour of Right Ascension (J2000)
52- 53 I2 min RAm Minute of Right Ascension (J2000)
55- 59 F5.2 s RAs Second of Right Ascension (J2000)
61 A1 --- DE- Sign of the Declination (J2000)
62- 63 I2 deg DEd Degree of Declination (J2000)
65- 66 I2 arcmin DEm Arcminute of Declination (J2000)
68- 71 F4.1 arcsec DEs Arcsecond of Declination (J2000)
73- 78 F6.3 mag Vmax [14.108/18.526] Out-of-eclipse V magnitude
based on the OGLE database (see Pawlak et al.
2013, J/AcA/63/323)
80- 85 F6.3 mag B-V [-0.284/0.445] Photometric index by
Zaritsky et al. (2002, J/AJ/123/855) or
Massey (2002, Cat. II/236)
87- 92 F6.3 mag (B-V)0 [-0.611/-0.069] Dereddened value of B-V
94-101 A8 --- SpType Spectral type
103 A1 --- r_SpType [cd] Reference for SpType (1)
--------------------------------------------------------------------------------
Note (1): Reference as follows:
c = North et al. (2010A&A...520A..74N 2010A&A...520A..74N);
d = Evans et al. (2004, J/MNRAS/353/601).
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 A17 --- OGLE-III OGLE III system name (OGLE SMC-ECL-NNNNN
in Simbad)
19- 23 F5.2 deg i [71.06/92.02] Inclination
25- 28 F4.2 deg e_i [0.22/1.89] Uncertainty in i
30- 34 I5 K T1 [10500/29000] Fixed value of primary
temperature
36- 40 I5 K T2 [10590/31350] Computed temperature
42- 45 I4 K e_T2 [231/1216] Uncertainty in T2
47- 50 F4.1 % L1 [6/77.1] Luminosity ratio of first component
in the I filter
52- 54 F3.1 % e_L1 [0.7/7] Uncertainty in L1
56- 59 F4.1 % L2 [12.6/57.8] Luminosity ratio of second
component in the I filter
61- 63 F3.1 % e_L2 [0.3/4.1] Uncertainty in L2
65- 68 F4.1 % L3 [0/73.1] Luminosity ratio of third component
in the I filter
70- 72 F3.1 % e_L3 [0.7/7.5]? Uncertainty in L3
74- 78 F5.3 --- R1/a [0.116/0.285] Relative radius of primary
80- 84 F5.3 --- e_R1/a [0.002/0.009] Uncertainty in R1/a
86- 90 F5.3 --- R2/a [0.129/0.296] Relative radius of secondary
92- 96 F5.3 --- e_R2/a [0.002/0.009] Uncertainty in R2/a
98-107 F10.4 d HJD0 [50716/55610.3] Heliocentric Julian Date
(HJD-2400000)
109-114 F6.4 d e_HJD0 [0.0006/0.0209] Uncertainty in HJD0
116-124 F9.7 d Per [1.25112/3.80228] Period
126-134 F9.7 d e_Per [4e-07/1.12e-05] Uncertainty in Per
136-140 F5.3 --- e [0.009/0.333] Eccentricity of the orbit
142-146 F5.3 --- e_e [0.002/0.088] Uncertainty in e
148-152 F5.1 deg omega [2.7/335.5] Argument of periastron ω0
at a reference time of HJD0
154-157 F4.1 deg e_omega [0.8/18.5] Uncertainty in omega
159-163 F5.1 yr U [7.2/190.2] Apsidal motion period
165-168 F4.1 yr e_U [0.3/43.7] Uncertainty in U
-------------------------------------------------------------------------------
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 A17 --- OGLE-III OGLE III system name (OGLE SMC-ECL-NNNNN
in Simbad)
19- 31 F13.5 d HJD Heliocentric Julian Date of minimum
33- 39 F7.5 d e_HJD [0/0.10655] Uncertainty in HJD
41- 42 A2 --- Filt [B R I] Filter used
44- 51 A8 --- Ref Source/Observatory
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History:
From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 27-May-2019