23 research outputs found
Light Curve and orbital period analysis of the eclipsing binary AT Peg
CCD photometric observations of the Algol-type eclipsing binary AT Peg have
been obtained. The light curves are analyzed with modern techniques and new
geometric and photometric elements are derived. A new orbital period analysis
of the system, based on the most reliable timings of minima found in the
literature, is presented and apparent period modulations are discussed with
respect to the Light-Time effect (LITE) and secular changes in the system. The
results of these analyses are compared and interpreted in order to obtain a
coherent view of the system's behaviour.Comment: 2 pages, 2 figures, contribution to the conference proceedings: IAU
Symposium 282 - From Interacting Binaries to Exoplanets: Essential Modeling
Tools, Tatransk\'a Lomnica, Slovakia, 18-22 Jul. 201
Markov Chain Monte Carlo Optimization applied to Dyson's Visual Double Stars
Estimates of orbital parameters were made using a Bayesian optimization
technique on astrometric data for 25 visual binary systems catalogued a century
ago by the ninth Astronomer Royal, Sir Frank Dyson. An advantage of this method
is that it provides reliable, unbiased uncertainty estimates for the optimized
parameters. Reasonable agreement is found for the short period (< 100 yr)
systems between the current study and Dyson, with superior estimation for the
longer systems through the inclusion of an additional century of data.
Dynamical masses are presented for the systems through the inclusion of
parallax measurements.Comment: 15 pages, 6 figures, 3 tables. Accepted by JAAVS
The enigmatic multiple star VV Ori
New photometry, including TESS data, have been combined with recent
spectroscopic observations of the Orion Ib pulsating triple-star system VV Ori.
This yields a revised set of absolute parameters with increased precision. Two
different programs were utilized for the light curve analysis, with results in
predictably close agreement. The agreement promotes confidence in the analysis
procedures. The spectra were analysed using the {\sc FDBinary} program. The
main parameters are as follows: and
(M). We estimate an approximate mass of the wide companion as M. Similarly, , , (R); , and (K). The close
binary's orbital separation is (R); its age is
(Myr) and its photometric distance is pc. The primary's Cep
type oscillations support these properties and confirm our understanding of its
evolutionary status. Examination of the well-defined 6678 He I
profiles reveals the primary to have a significantly low projected rotation:
some 80\% of the synchronous value. This can be explained on the basis of the
precession of an unaligned spin axis. This proposal can resolve also observed
variations of the apparent inclination and address other longer-term
irregularities of the system reported in the literature. This topic invites
further observations and follow-up theoretical study of the dynamics of this
intriguing young multiple star.Comment: 17 pages, 15 figures, 14 tables, accepted by MNRA