J/A+A/659/A8 First study of four doubly eclipsing systems (Zasche+, 2022)
The first study of four doubly eclipsing systems.
Zasche P., Henzl Z., Kara J.
<Astron. Astrophys. 659, A8 (2022)>
=2022A&A...659A...8Z 2022A&A...659A...8Z (SIMBAD/NED BibCode)
ADC_Keywords: Binaries, eclipsing ; Photometry ; Optical
Keywords: stars: binaries: eclipsing - stars: fundamental parameters
Abstract:
We present the discovery and the very first analysis of four stellar
systems showing two periods of eclipses, that are the objects
classified as doubly eclipsing systems. Some of them were proved to
orbit each other thanks to their eclipse-timing-variations (ETVs) of
both pairs, hence they really constitute rare quadruples with two
eclipsing pairs. Some of them do not, as we are still waiting for more
data to detect their mutual movement. Their light curves and period
changes were analysed. All of them are detached and near-contact, but
none of them contact; moreover, to our knowledge none of these stars
can be considered as blend of two spatially unresolved close
components on the sky. These systems are CzeV2647 (0.5723296+0.9637074
days), proved to orbit with 4.5-year periodicity; CzeV1645
(1.0944877+1.6594641 days), with a rather questionable detection of
ETV; CzeV3436 (0.6836870+0.3833930 days); and, finally, OGLE
SMC-ECL-1758 (0.9291925+3.7350826 days), proved to move on its 30-year
orbit. Even more surprising is the fact that most of these systems
show the ratio of their two orbital periods close to coupling near
some resonant values of small integers, namely CzeV2647, with only 1%
from 3:5 resonance, CzeV1645 1% from 2:3 resonance, and OGLE
SMC-ECL-1758 with only 0.49% from 1:4 resonance. The nature of these
near-resonant states still remains a mystery.
Description:
The ground-based observations were obtained by one of the authors,
Z.H., at his private observatory in Velteze u Loun, Czech Republic. A
quite untypical observational setup was used due to the filter used
for that data, namely the astrophotographic Baader UV/IR Sperrfilter.
It very effectively cuts almost all signal below 400nm and above
700nm.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 113 4 Information about systems under analysis
etv.dat 58 1550 Derived heliocentric minima of the systems
used for our analysis
photom.dat 48 15817 New ground-based photometric data
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 A17 --- Star Name of the star
19- 36 A18 --- OName Other name
38- 39 I2 h RAh Right ascension (J2000.0)
41- 42 I2 min RAm Right ascension (J2000.0)
44- 47 F4.1 s RAs Right ascension (J2000.0)
49 A1 --- DE- Declination sign (J2000)
50- 51 I2 deg DEd Declination (J2000)
53- 54 I2 arcmin DEm Declination (J2000)
56- 59 F4.1 arcsec DEs Declination (J2000)
61- 65 F5.2 mag magmax Out-of-eclipse magnitude, in Filter
67 A1 --- Filter [VI] Filter (1)
69- 73 I5 K Teff Effective temperature
75-113 A39 --- r_Teff Effective temperature reference
--------------------------------------------------------------------------------
Note (1): Vmag from UCAC4 catalogue (Zacharias et al., 2013AJ....145...44Z 2013AJ....145...44Z), or
Guide Star Catalog II (Lasker et al., 2008AJ....136..735L 2008AJ....136..735L),
Imag from OGLE survey (Pawlak et al., 2013AcA....63..323P 2013AcA....63..323P).
--------------------------------------------------------------------------------
Byte-by-byte Description of file: etv.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 A17 --- Star Name of the star
19- 23 A5 --- Pair Pair A/B
25- 35 F11.5 d HJD Heliocentric JD of Minimum (HJD-2400000)
37- 43 F7.5 d e_HJD Error of HJD
45- 47 A3 --- Filter Filter used
49- 58 A10 --- Ref Source/Observatory
-------------------------------------------------------------------------------
Byte-by-byte Description of file: photom.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 A17 --- Star Name of the star
20- 31 F12.6 d HJD Heliocentric Julian Date (HJD-2400000)
33- 39 F7.4 mag dmag Differential magnitude in Filter
41- 46 F6.4 mag e_dmag Error of magnitude
48 A1 --- Filter [RS] Photometric filter used
-------------------------------------------------------------------------------
Acknowledgements:
Petr Zasche, zasche(at)sirrah.troja.mff.cuni.cz
(End) Patricia Vannier [CDS] 15-Mar-2022