Radial Velocity Studies of Close Binary Stars. VI.

Abstract

Radial-velocity measurements and sine-curve fits to the orbital velocity variations are presented for the sixth set of ten close binary systems: SV Cam, EE Cet, KR Com, V410 Cyg, GM Dra, V972 Her, ET Leo, FS Leo, V2388 Oph, II UMa. All systems except FS Leo are double-lined spectroscopic binaries. The type of FS Leo is unknown while SV Cam is a close, detached binary; all remaining systems are contact binaries. Eight binaries (all except SV Cam and V401 Cyg) are the recent photometric discoveries of the Hipparcos satellite project. Five systems, EE Cet, KR Com, V401 Cyg, V2388 Oph, II UMa, are members of visual/spectroscopic triple systems. We were able to observe EE Cet separate from its companion, but in the remaining four triple systems we could separate the spectral components only through the use of the broadening-function approach. Several of the studied systems are prime candidates for combined light and radial-velocity synthesis solutions.RS CVn-type system.Our double-lined (SB2) spectroscopic orbit is very well defined, with small errors of the orbital parameters. We note that determinations of the radial velocity semi-amplitude of the primary component, K 1 , agree well in the four existing solutions. Starting with Hiltner (1953) (as reanalyzed by Rainger et al. (1991)), Rainger et al. (1991), Pojmanski (1998) and the current, the results have been (in km s −1 ) : 121.7 ± 1.9, 122.3 ± 1.5, 118.5 ± 2.0, and 121.86 ± 0.76. The results of Pojmanski (1998) differ the most, but are still within the errors of the solutions. The center of mass velocity, V 0 , seems to show a secular progression, although the data of Pojmanski (1998) deviate from the trend. In the same order as before: −16.2 ± 1.4, −11.2 ± 1.2, −13.7 ± 1.5 and −9.13 ± 0.78 km s −1 . Noting that the observations were made in 1947, 1988, 1993 and 1997, the trend may be related to the motion about the third body with the period of about 65 -75 years and the semi-amplitude of about 2 km s −1 (Rainger et al. 1991).The results of Pojmanski (1998), although the first to reveal the motion of the secondary component, show deviations described above and, even more importantly, differ rather substantially from our results in the value of K 2 : 211.5 ± 5.5 versus our 190.17 ± 1.73 km s −1 . Possibly, the discrepancies are due to the rather complex reduction scheme of the previous study which involved successive removal of the two spectral signatures from individual spectra. This was entirely unnecessary in our case because the broadening functions that we analyzed were very well defined and radial velocities of both components could be measured with great ease. Figure 4 shows one of the broadening functions for SV Cam, in comparison with other systems analyzed in this paper. On the basis of the widths of the individual signatures in the broadening functions, and taking into consideration the instrumental broadening, we estimate the apparent rotation velocity of the components, V 1 sin i = 122 ± 10 km s −1 and V 2 sin i = 85 ± 8 km s −1 . Patkos & Hempelman...

Radial Velocity Studies of Close Binary Stars. X.

“…This paper is a continuation of a series of papers Rucinski et al 2000Rucinski et al , 2001Rucinski et al , 2002Rucinski et al , 2003Lu et al 2001;; hereafter Papers I-VI, VIII, and IX) of radial velocity studies of close binary stars and presents data for the ninth group of 10 close binary stars observed at the David Dunlap Observatory. For technical details and conventions, and for preliminary estimates of uncertainties, see the interim summary paper (Rucinski 2002a, hereafter Paper VII).…”

The eclipsing active star SV Camelopardalis

“…Hereafter we give a new light curve solution based on new measurements of the spectroscopic mass ratio. Rucinski et al (2002) determined q = 0.641 ± 0.007 for the components of SV Cam.…”

Evaluating Gaia performances on eclipsing binaries

“…This is reported in literature as a mid-F to mid-G system with 0.6 day period and a light-curve of the β Lyrae type. There is a long history of observations and analyses of this system, with extensive photometry (e.g., Kjurkchieva et al 2000;Patkós 1982;Zeilik et al 1988), and spectroscopy (e.g., Hempelmann et al 1997;Kjurkchieva et al 2002;Lehmann et al 2002;Özeren et al 2001;Pojmański 1998;Popper 1996;Rainger et al 1991;Rucinski et al 2002). Most authors have interpreted asymmetries in the light curves and the variation in them as due to spots.…”