- HEASARC Director: Dr. Alan P. Smale
- HEASARC Associate Director: Dr. Roger Brissenden
- NASA Official: Phil Newman
- Web Curator: Meredith Gibb
- Last Modified: 19-Jul-2010
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RASSASASEB - RASS/All-Sky Automated Survey Eclipsing Binaries Catalog |
HEASARC Archive |
The authors expect that only 1.4% (i.e., 12 out of 836) of the matches between the ASAS eclipsing binary and RASS sources will be false given their maximum angular separation criterion of 50 arcseconds. This Browse table excludes 29 contact binaries for which the separate distance estimates made by the authors using the source V-band and I-band magnitudes differed by more than 20%, and hence contains 807 (836 - 29) eclipsing and X-ray emitting binary systems.
Complete information on ASAS and its freely accessible data are available at the ASAS web site: http://www.astrouw.edu.pl/asas/.
Coronal activity from the ASAS eclipsing binaries.
Szczygiel D.M., Socrates A., Paczynski B., Pojmanski G., Pilecki B.
<Acta Astron., 58, 405-418 (2008)>
=2008AcA....58..405S (SIMBAD/NED BibCode)
Asas_Name
The ASAS source identification in the recommended
format using the truncated J2000.0 equatorial coordinates , e.g.,
'ASAS JHHMMSS+DDMM.m'.
Name
THe RASS source identification in the recommended
format using the truncated J2000.0 equatorial coordinates , e.g.,
'1RXS JHHMMSS.s+DDMMSS'.
RA
The Right Ascension of the RASS Source in the selected equinox.
This was created by the HEASARC from the RASS name and hence has
a precision of 0.1 seconds of time.
Dec
The Declination of the RASS Source in the selected equinox.
This was created by the HEASARC from the RASS name and hence has
a precision of 1 arcsecond.
LII
The Galactic Longitude of the RASS Source.
BII
The Galactic Latitude of the RASS Source.
Offset
The angular separation between the ASAS and RASS source
positions, in arcseconds.
Period
The orbital period P of the binary, in days.
Minimum_Epoch
The heliocentric date/time of the epoch of minimum light
of the eclipsing binary. This was given as a 'modified' Julian Date
(HJD - 2450000), where HJD is the heliocentric Julian Date, to a precision
of 0.001 days, i.e., of about 1.4 minutes. Given this level of precision, and
remembering that HJD and the
Barycentric Julian Date (BJD) differ by no more than +/- 4 seconds, this
date/time is thus essentially barycentric also.
Max_Vmag
The V-Band brightness at maximum light, expressed as an apparent
magnitude.
Max_Imag
The I-Band brightness at maximum light, expressed as an apparent
magnitude.
Distance
The distance D to the eclipsing binary, in parsecs. This was
calculated as discussed
in Section 4 of the reference paper using a main-sequence fit
for the detached and semi-detached systems (treating them as single stars) from
Hawley et al. (1999, AJ, 117, 1341) assuming solar metallicity, and a fit
from Rucinski and Duerbeck (1997, PASP, 109, 1340) for the contact binaries.
Log_Lbol
The logarithm of the bolometric luminosity of the binary system, in erg/s,
based on the observed magnitude, the calculated distance and an adopted
bolometric correction, as discussed in Section 4.1 of the reference paper.
Hardness_Ratio
The hardness ratio HR = (H-S)/(H+S) of the RASS X-ray
source, where H is the counts in the 0.5-2.0 keV energy range and S
is the counts in the 0.1-0.4 keV energy range.
Hardness_Ratio_Error
The uncertainty in the hardness ratio.
RASS_Count_Rate
The ROSAT All-Sky Survey X-ray source count rate, CR, in
counts per second (ct/s).
RASS_Count_Rate_Error
The uncertainty in the RASS X-ray source count rate,
in counts per second (ct/s).
Log_Lx
The logarithm of the X-ray luminosity of the RASS source. in erg/s,
based on the observed count rate, CR, and hardness ratio HR of the X-ray
source, and the estimated distance D in the usual manner for RASS sources:
f_X = CR * (5.30*HR + 8.7) * 1.0E-12
L_X = 1.20E38 * D2 * f_X
Log_Rossby_Number
The logarithm of the Rossby Number for the eclipsing
binary log R_0 = log (P_rot/tau_C), where the rotational period P_rot is
assumed to be equal to the orbital period P, i.e., the system is assumed to be
tidally locked, for those binaries with orbital periods less than 10 days,
and tau_C is the convective turnover time of the primary star and is
calculated as discussed in Section 6 of the reference paper.
Alt_Name
Another identification for the binary from the literature,
mainly from the GCVS.
Binary_Type
The ASAS classification of the variability type of the
binary, where EC = contact (W UMa type), ESD = semi-detached (Algol), and
ED = detached binary.
Class
The HEASARC Browse object classification, based on the binary_type,
where we have called detached (ED) systems "RS CVn systems". While it is
true that most RS CVn binaries are detached, a few are semi-detached, so
that there is not a precise one-to-one match between these classes.