Astronomical Data Center
ADC/CDS Standard Document for Catalog:
/journal_tables/PASP/105/1433/
The following is the "ReadMe" document that describes this ADC catalog. You can access the files described here in three ways:
J/PASP/105/1433 Light Curves of W UMa Systems (Rucinski 1993)
================================================================================
A Simple Description of Light Curves if W UMa Systems
Rucinski S.M.
<Publ. Astron. Soc. Pac. 105, 1433 (1993)>
=1993PASP..105.1433R (SIMBAD/NED Reference)
================================================================================
ADC_Keywords: Stars, variable; Binaries, contact
Abstract:
Fourier cosine coefficients a(1) to a(6) are tabulated and shown
graphically for light curves of contract binary stars of one (solar)
effective temperature, with orbital inclinations (i),
30 deg.le.i.le.90deg., mass ratios (q), 0.05.le.q.le.1, and three
values of the degree of contact, f=0, 0.5, 1. The coefficients, combined
with additional tables of depths of minima, can be used for statistical
estimates of ensemble properties of light curves of contact systems in
stellar systems or for approximate determinations of orbital elements
of individual contact binaries. Tables of all eleven coefficients a(0)
to a(10) for all combinations of i and q are accessible using the ftp
file-transfer mechanism.
Introduction:
There is a need for a simple method to obtain essential parameters for
contact binaries without the necessity for full light-curve synthesis
solutions. A statistical method is also required to determine the
expected distribution of variability amplitudes with observations.
Only one set of temperature is given: the solar case with T(eff)=5770 K,
for photometric band V, with gravity darkening exponent beta=0.08 in
T(eff) proportional to g to the beta and bolometric albedo A=0.5.
Nevertheless. the calculations should be applicable to a large range of
effective temperatures. Light curves depend practically only on three
parameters, the mass ratio, q, the inclination, i, and the degree of
contact, f.
The observed light curve should be expressed in light units, relative to
the maximum at phases 0.25 or 0.75. (If the maxima are unequal, use the
higher maximum.) A very good representation of a light curve can be
usually obtained by calculating the Fourier series l = sum
(ai*cos(2*pi*i*phase) and then truncating the curved part of the
secondary (occultation) eclipse at the level l(180) using the tables of
b the depth of secondary minima, 1-l(180)).
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
coef_f0.dat 91 500 Coefficients for f=0 (Inner Contact)
coef_f05.dat 91 500 Coefficients for f=0.5
coef_f1.dat 91 500 Coefficients for f=1 (Outer Contact)
min_f0.dat 28 500 Depth of minimum for f=0
min_f05.dat 28 500 Depth of minimum for f=0.5
min_f1.dat 28 500 Depth of minimum for f=1
--------------------------------------------------------------------------------
Byte-by-byte Description of file: coef_f0.dat, coef_f05.dat, coef_f1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 F7.3 deg i The inclination
8-14 F7.3 --- q The mass ratio
15-21 F7.3 --- a0 The coefficient, a(0)
22-28 F7.3 --- a1 The coefficient, a(1)
29-35 F7.3 --- a2 The coefficient, a(2)
36-42 F7.3 --- a3 The coefficient, a(3)
43-49 F7.3 --- a4 The coefficient, a(4)
50-56 F7.3 --- a5 The coefficient, a(5)
57-63 F7.3 --- a6 The coefficient, a(6)
64-70 F7.3 --- a7 The coefficient, a(7)
71-77 F7.3 --- a8 The coefficient, a(8)
78-84 F7.3 --- a9 The coefficient, a(8)
85-91 F7.3 --- a10 The coefficient, a(10)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: min_f0.dat, min_f05.dat, min_f1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 F7.3 deg i The inclination
8-14 F7.3 --- c The mass ratio
15-21 F7.3 --- l0 Depth of minimum for eclipse of more massive
component
22-28 F7.3 --- l180 Depth of minimum for eclipse of less massive
component
--------------------------------------------------------------------------------
Each line contains the value of inclination (degr), mass-ratio, and two
depths of minima 1-l(0) and 1-l(180) for eclipses of more- and
less-massive components, respectively. The division into three parts
according to the degree of contact is the same as for "coef"
Note that a very good representation of a light curve can be usually
obtained by calculating the Fourier series l = sum (ai*cos(2*pi*i*phase)
and then truncating the curved part of the secondary (occultation)
eclipse at the level l0 using the tables of the depth of secondary
minima, l180.
--------------------------------------------------------------------------------
(End) Nancy G. Roman [ADC/SSDOO] Sep-6-1995
Go to ADC Home Page