PST1 > Science

1.  Key science projects

Currently our studies with PST1 focuses on two main projects. First is a program of monitoring pulsating stars like cepheids and SPBs to improve theories of internal stellar structure and oscillations. The second is a program of deriving precise models of eclipsing binary stars to test evolution theories and calibrate distance measurements to nearby galaxies.

2.  First model of a binary system FM Leo

Together with David Dunlap Observatory we have made first spectroscopic observations of binary eclipsing star FM Leo. Wilson-Devinney analysis of the system have shown that it is possible to derive accurate stellar parameters with errors of about 0.5% for masses and 3% for radii. FM Leo seems to be composed of two main sequence stars, with the age of about 3 Gyr.

Click here to read full paper.

3.  The longest-period overtone Cepheid - V440 Per - confirmed

Spectroscopic observations from PST1 made it possible to finally resolve conflicting models for V440 Per Cepheid. We have been able to securely detect first harmonic of aplitude of 140 m/s and confirm that V440 Per is indeed an overtone pulsator.

Click here to read full paper.

4.  Monitoring pulsations of gamma Peg

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gamma Pegasi
Radial velocity curve of a hybrid pulsating star gamma Pegasi.

5.  Binary eclipsing star of V2080 Cyg

V2080 Cyg
Radial velocity curve of eclipsing binary star V2080 Cyg from two sources: PST1 (black) and David Dunlap Observatory (red). All data was fitted using eccentric orbit model. Residuals with respect to the model were calculated for all phases and for phases away from eclipses. The second estimate is closer to PST1 precision, because cross-correlations peaks from both stars are well separated.

6.  Four-component spectroscopic multiple system confirmed

multiple system
Changes of cross-correlation functions for several different phases of a newly discovered stellar system most likely composed of four stars. Our PST1 observations have confirmed previous reports indicating that this V~9 mag star is indeed a multiple system and all components are detectable in optical spectra.

7.  First extrasolar planet radial velocity observations from Poland

tau Bootis
Radial velocity curve of tau Bootis star showing periodic changes due to the presence of a massive planet.
Page last modified on October 30, 2011, at 11:08 PM