Division IV: Stars

The Henize sample of S stars IV . New symbiotic stars ⋆

The properties of the few symbiotic stars detected among the 66 binary S stars from the Henize sample are discussed. Two stars (Hen 18 and Hen 121) exhibit both a strong blue-violet continuum and strong Hα emission (FWHM of 70 km s ), whereas Hen 134 and 137 exhibit weak Hα emission. The Hα profiles are typical of non-dusty symbiotic stars belonging to class S-3 as defined by Van Winckel et al....

Unweighted p-center problem on extended stars

An extended star is a tree which has only one vertex with degree larger than two. The -center problem in a graph  asks to find a subset  of the vertices of  of cardinality  such that the maximum weighted distances from  to all vertices is minimized. In this paper we consider the -center problem on the unweighted extended stars, and present some properties to find solution.

New binary stars discovered by lunar occultations. IV

We report on a total of 20 sources observed in the near infrared in the course of routine lunar occultation programs at the TIRGO and Calar Alto observatories. The results consist either in discoveries of new binaries, or in re–observations of known or suspected binaries where only incomplete information was previously available. For the first time, a companion has been detected around the foll...

LINEAR PULSATION CHARACTERISTICS OF MIRA VARIABLE STARS

The linear adiabatic pulsation-periods of Mira variable stars have been derived. Approximately 2701[1]models were calculated for M = 0.7 MΘ to 2 MΘ stars with radii from 180 RΘ to 340 RΘ and luminosities from 2800 LΘ to 10,000 LΘ. The chemical composition of all models is (X,Z) = (0.7,0.02). From the result of this study, linear relations on Luminosity-Period-Mass relationship and luminosity-pe...

Triangulaizability of Algebras Over Division Rings