Physical parameters of multiple systems like the trapezium of early spectral types, derived fromuvbyβ photometry. I

The results of electrophotometric observations of 51 stars in multiple systems of the Trapezium type in the Strömgren-Crawford six-color photometric system are given. The following Trapezia were selected from the Abastumani Catalog for observations: ABAO 2, 8, 34, 48, 51, 62, 94, 313, 316, 348, 356, 359, 363, 387, 396. The observations were made on the 125-cm, automatically computer controlled, reflecting telescope of Abastumani Astrophysical Observatory. The results of the observations are given in Table 1. Most of the components of the observed Trapezia belong to the early “B ” group based on Stromgren ’s criteria. The absolute stellar magnitudes of the Trapezia components are determined and their distance moduli are calculated (Table 2). It is concluded that these Trapezia are physical systems with a high probability.     

Discrimination between stochastic dynamics patterns of ambient noises (Case study for Oni seismic station)

Investigation of complex dynamics of ambient seismic noise remains as an important scientific research challenge. In this work we investigated dynamical features of the ambient noises at Oni seismic station, Georgia. We used stochastic model reconstruction method from measured data sets. Seismic records for different time periods around Oni seismic station have been analysed. It was shown that the dynamics of fluctuations of seismic noise vertical component undergoes essential changes for considered time period from 2005 to 2012. These changes are more noticeable for time periods of preparation and aftershock activity of strong M6.0 earthquake occurred in 2009 in the vicinity of Oni seismic station.     

New multiple systems of the Trapezium type

In the Guide Star Catalog (GSC) 223 new trapezia have been found. A new, more complete list of trapezia, including 637 objects, has been compiled on the basis of the GSC and the Washington Double Star Catalog. Translated from Astrofizika, Vol. 42, No. 4, pp. 571–578, October–December, 1999.     

Physical parameters of multiple systems like the trapezium of early spectral types, derived fromuvbyβ photometry. II

The effective temperatures T_eff, gravitational force g at the stellar surface, and Fe/H have been calculated for 50 components of 15 Trapezia of early spectral types from electrophotometric observations in the six-color uvbyβ photometric system. The results of the calculation showed that the log T_eff of Trapezia components lie in the range 4.03–4.54, while their log g lie in the range 2.58–4.02. The atmospheric parameters T_eff and g were used to determine the stars’ masses and ages based on Hejlesen’s calculated evolutionary model sequences. All the Trapezia components have several times more mass than the sun and almost half of them have over 10 times that mass. Over 70% of the components are less than 40.10⁶ years old. Translated from Astrofizika, Vol. 41. No. 2. pp. 235–244, April-June, 1998.