J/A+A/415/289 UBVRI light curves of ER Vul (Harmanec+, 2004)
An improved ephemeris and physical elements of ER Vul.
Harmanec P., Bozic H., Thanjavur K., Robb R.M., Ruzdjak D., Sudar D.
<Astron. Astrophys. 415, 289 (2004)>
=2004A&A...415..289H 2004A&A...415..289H
ADC_Keywords: Binaries, eclipsing ; Photometry, UBVRI
Keywords: stars: close - stars: binaries: eclipsing -
stars: binaries: spectroscopic - stars: fundamental parameters -
stars: individual: ER Vul
Abstract:
New photoelectric UBV and BVRI observations, secured during
August-November of 2002 at two observatories distant in local time are
analyzed together with two earlier photometric data sets and all
available radial velocities to derive the most accurate ephemeris of
the binary and to set limits on its basic physical elements. These
observations were obtained as a support for a high-dispersion
spectroscopic study, results of which will be published separately. It
was found that radial velocities and photometric observations spanning
53 years can be reconciled with the linear ephemeris
T(prim.min.)=HJD 2440182.25628(46) + 0.698095113(29)days x E, where
the rms errors of the last digits are given in brackets. Masses of the
stars are 1.02 and 0.97 solar masses and the binary separation is
4.170 solar radii. There is still a large uncertainty in the stellar
radii. We also report the discovery of rapid light variations on a
time scale of hours seen in the U band light curve and offer a few
thoughts on the future investigation of this binary.
Description:
Individual UBVRI photoelectric observations of ER Vul (new ones and
compiled from the literature and brought to a comparable scale) are
given. See the text for the details of data reduction, comparison
stars etc...
Objects:
-----------------------------------------
RA (2000) DE Designation(s)
-----------------------------------------
21 02 25.9 +27 48 26 ER Vul
-----------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table4.dat 31 4453 Heliocentric Julian dates, (U,B,V,R,I) magnitudes
and weights of photometric observations of ER Vul
--------------------------------------------------------------------------------
See also:
J/A+A/402/745 : Radial velocities of ER Vul (Duemmler+, 2003)
J/AN/323/31 : UBVR light curves of ER Vul and RT And (Ekmekci+, 2002)
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 12 F12.4 --- HJD Heliocentric Julian date of observation
15 A1 --- Band [VBURI] Band
17- 22 F6.3 mag mag Magnitude in Band (V, B, U, R, I)
25- 28 F4.2 --- w weight of observation
30- 31 I2 --- Code Numerical code for magnitude and station (1)
--------------------------------------------------------------------------------
Note (1): Numerical code for magnitude and station:
----------------------------------------
Station V B U R I
DDO 21 25
Hipparcos 22
Hvar 23 26 28
Victoria 24 27 29 30
--------------------------------------------------------------------------------
Acknowledgements: Petr Harmanec
Astronomical Institute of the Charles University, Prague,
Czech Republic
(End) Patricia Bauer [CDS] 14-Nov-2003