The pre-main-sequence binary HK Ori: spectro-astrometry and EXPORT data

The pre-main sequence binary HK Ori - Spectro-astrometry and EXPORT data

In this paper we present multi-epoch observations of the pre-main sequence binary HK Ori. These data have been drawn from the EXPORT database and are complemented by high quality spectro-astrometric data of the system. The spectroscopic data appear to be very well represented by a combination of an A dwarf star spectrum superposed on a (sub-)giant Gtype spectrum. The radial velocity of the syst...

Detection of Pre-main-sequence Binaries Using Spectro-astrometry

The technique of spectro-astrometry (measuring wavelength dependence of the position of an object) has been used to observe a number of pre-main-sequence stars. Several previously known binaries with separations down to 100 milli-arcseconds (mas) were easily detected in these observations by the presence of a broad feature in the position spectrum on the H line. The observations show that T CrA...

A Spectro-astrometric study of southern pre-main sequence stars

We present spectro-astrometric observations for 28 southern pre-main sequence (PMS) stars and investigate their circumstellar environment down to AU scales. The structures detected in the “position spectra” include: (1) almost all the known binary companions in our sample (Sz 68, Sz 41, HO Lup, VW Cha, S CrA, AS 205), (2) companion candidates which have not been detected by infrared speckle tec...

Activity Cycles in Lower Main Sequence and Post Main Sequence Stars: the Hk Project

KH 15D: Gradual Occultation of a Pre–Main-Sequence Binary

We propose that the extraordinary “winking star” KH 15D is an eccentric pre–mainsequence binary that is gradually being occulted by an opaque screen. This model accounts for the periodicity, depth, duration, and rate of growth of the modern eclipses; the historical light curve from photographic plates; and the existing radial velocity measurements. It also explains the re-brightening events tha...