Spectroscopy and photometry of companion stars 2 and 3 to supernova 1987A
| Autor: | Mark M. Phillips, Nolan R. Walborn, Alistair R. Walker, Jonathan H. Elias |
|---|---|
| Rok vydání: | 1993 |
| Předmět: |
Physics
Astronomy Cataclysmic variable star Astronomy and Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics Light curve Astronomical spectroscopy Photometry (optics) Stars Supernova Apparent magnitude Space and Planetary Science Astrophysics::Solar and Stellar Astrophysics Astrophysics::Earth and Planetary Astrophysics Equivalent width Astrophysics::Galaxy Astrophysics |
| Zdroj: | Publications of the Astronomical Society of the Pacific. 105:1240 |
| ISSN: | 1538-3873 0004-6280 |
| DOI: | 10.1086/133302 |
| Popis: | The spectra of both close companion stars to SN 1987A in the LMC have been classified as type B2 from blue-violet digital data; the H-gamma equivalent width of Star 2 and the absolute visual magnitude of both stars correspond to giant luminosity classes. The near-ultraviolet, visual, and infrared colors of Star 2 are found to be consistent with that classification, but Star 3 exhibits both UV and IR excesses as well as variable magnitudes, which are consistent with a Be object, as recently reported from the presence of broad h-alpha emission. Paradoxically, Star 2 has relatively broad, shallow absorption lines indicative of a moderately rapid rotator, whereas Star 3 has sharper lines, indicating that it is viewed pole-on. The derived evolutionary ages of the companions correspond roughly to coevality with Sk-69degrees202, the B3 I progenitor of SN 1987A, but the discrepancies and uncertainties in current Teff, Mbol calibrations unfortunately render this conclusion somewhat indefinite. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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