Orion-2: First Scientific Results
Abstract
The ultraviolet spectral images of thousands of faint stars, up to the 13th mag., in the wavelength region of 2000 5000 Å are obtained by means of the space astrophysical observatory Orion-2 aboard the spaceship Soyuz-13. These spectrograms were designed generally for an investigation of the continuous spectra of the stars in ultraviolet. The processing and measurement of part of the material available confirm the expectations for the solution of a large number of problems concerning the physics of stars and stellar atmospheres. Some of the results obtained are included in the present review. Particularly, the observed distribution of continuous energy in the ultraviolet of normal hot stars is in line, according to Orion-2 data, with theoretical prediction; the existence of a new type of high temperature (> 20000K) and low absolute luminosity stars is noticed; the blocking effect of the ultraviolet absorption lines expected for the A-type stars is confirmed; a number of empirical regularities concerning the behaviour of the ultraviolet doublet of ionized magnesium, 2800 Mg ii, in the stellar spectra are derived; the chromosphere in cold stars is detected; the role of a multiplet of ionized titanium, 3080 Ti ii, in stellar spectra is revealed; probably an abnormal silicon-rich stellar envelope around a Be-type star is discovered; a new method for the spectral classification of the stars by their ultraviolet spectral images is developed; a range of interesting facts relating to the structure of the ultraviolet spectra of middle type stars (F-K) come to the fore; an exceptional ultraviolet spectrogram for the planetary nebula II 2149 and its nuclei is obtained; the blocking effect of emission lines in the spectrum of the B-type emission and normal O-type stars has been detected; a remarkably faint (12itm.6) and high temperature star (No. 1) of strange spectral structure has been discovered.
- Publication:
-
Space Science Reviews
- Pub Date:
- October 1975
- DOI:
- 10.1007/BF00350198
- Bibcode:
- 1975SSRv...18...95G
- Keywords:
-
- Spaceborne Astronomy;
- Spectral Energy Distribution;
- Stellar Luminosity;
- Stellar Spectra;
- Ultraviolet Spectra;
- A Stars;
- Absorption Spectra;
- Astronomical Photography;
- Emission Spectra;
- Hot Stars;
- Line Spectra;
- Soyuz Spacecraft;
- Star Distribution;
- Astrophysics