5 research outputs found
Absolute parameters of the eclipsing binary V821 Cas from UBVRI light curves and radial velocities
We present UBVRI photometric measurements and spectroscopic observations of
the double-lined eclipsing binary V821 Cas. The radial velocities were obtained
by means of the cross-correlation technique. Simultaneous analyses of the
multi-band light curves and RVs give the absolute parameters for the stars as:
M=2.050.07 M, M=1.630.06 M,
R=2.310.03 R, R=1.390.02 R, T=9
400400 K, and T=8 600400 K. Analysis of the O-C residuals
yielded an apsidal motion in the binary at a rate of
=0^{\degr}.0149\pm0^{\degr}.0023 cycle, corresponding
to an apsidal period of U=11819 yr. Subtracting the relativistic
contribution we find that =-2.590 which is in agreement with the
value predicted by theoretical models. Comparison with current stellar
evolution models gives an age of yr for the system.Comment: 11 pages, including 6 figures and 6 tables, accepted for publication
in MNRA
New findings based on long-term photometric observations of the eclipsing binary V471 Tauri
Spectroscopic and photometric observations of the selected Algol-type binaries - III. LL Aquarii, MP Delphini and NSV 20913
Spectroscopic and photometric analysis of NSV 24512: an early-type eclipsing binary embedded in a dust cloud
We present differential V-band photometric observations and the first radial velocities of NSV 24512, which is embedded in the Serpens star-forming region. This double-lined system has an eccentric orbit with an eccentricity of 0.193. The system is a member of visual double star ADS 11410AB with a separation of about 0.3 arcsec and an apparent visual magnitude difference of 0.125 mag; we find that the fainter component (component B) is responsible for the periodic light variation. Therefore, we subtracted the light contribution of component A from the total light. The V-band photometric data and radial velocities were then analysed simultaneously using the Wilson-Devinney program. From the blue-wavelength spectroscopic observations and radial velocities, we classify the primary and secondary components as B8V and B9V stars, respectively. The masses and radii of the component stars have been derived as 3.68 +/- 0.05 and 3.36 +/- 0.04 M-circle dot and 3.21 +/- 0.05 and 2.93 +/- 0.05 R-circle dot, respectively. Comparison with theoretical evolutionary models indicates that both components are premain-sequence stars with an age of about 2.1 Myr. The projected rotational velocities of the components measured by us are much smaller than the synchronous rotational velocities. The high asynchronism is further evidence of the very young age of the system. Using the radiative properties of the stars, we have redetermined the distance to NSV 24512 as 247 +/- 5 pc, which is in good agreement with, and more precise than, previous determinations. Adopting the same interstellar extinction and distance, we classify component A to be of spectral type 137, if it is a single star