EX Lupi
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Star EX Lupi |
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| Artist's impression | |||||||
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| AladinLite | |||||||
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Observation dates equinox : J2000.0 , epoch : J2000.0 |
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| Constellation | wolf | ||||||
| Right ascension | 16 h 03 m 5.49 s | ||||||
| declination | -40 ° 18 ′ 25.4 ″ | ||||||
| Apparent brightness | 8.5 (8.5 to 14.3) mag | ||||||
| Typing | |||||||
| B − V color index | (2.9) | ||||||
| Spectral class | M0 | ||||||
| Variable star type | EXOR | ||||||
| Astrometry | |||||||
| parallax | (6.34 ± 0.04) mas | ||||||
| distance | (514 ± 3) ly (158) pc |
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| Proper movement | |||||||
| Rec. Share: | (−10.10 ± 0.08) mas / a | ||||||
| Dec. portion: | (−22.54 ± 0.05) mas / a | ||||||
| Physical Properties | |||||||
| Dimensions | 0.6 M ☉ | ||||||
| radius | 1.6 R ☉ | ||||||
| Luminosity |
0.7 L ☉ |
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| Effective temperature | 3800 K | ||||||
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Other names and catalog entries |
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EX Lupi is a variable star in the constellation Wolf . It is the prototype of a subclass of the T-Tauri stars known as EXors or EX-Lupi stars and characterized by optical outbreaks from 1 to 4 mag , each lasting about ten to one hundred days and with an interval of several months up to years. They are mostly dwarfs of the spectral classes K or M. Like all T-Tauri stars, EX Lupi is also young, only a few million years old.
A special feature of this young star is that Péter Ábrahám from the Konkoly Observatory in Budapest and his colleagues were able to observe how silicate crystals are formed. They concluded this from the fact that the typical lines of silicate crystals appeared in the star 's spectrum during an outbreak of radiation . This is taken as an indication of the origin of silicate crystals in comets .
Web links
- Max Planck Institute: Where were the comet crystals baked?
- GH Herbig: EX Lupi: History and Spectroscopy . In: The Astronomical Journal . tape 133 , no. 6 , 2002, pp. 2679-2683 , doi : 10.1086 / 517494 .
Individual evidence
- ↑ a b c d e f HD 325367. In: SIMBAD . Center de Données astronomiques de Strasbourg , accessed on October 31, 2018 .
- ↑ a b EX Lup. In: VSX. AAVSO, accessed October 31, 2018 .
- ↑ a b c d N. Sipos et al. : EX Lupi in quiescence . In: Astronomy & Astrophysics . tape 507 , no. 2 , 2009, p. 881-889 , doi : 10.1051 / 0004-6361 / 200911641 , arxiv : 0906.3168v1 .
- Jump up ↑ Young star: Radiation bursts create crystals. Retrieved September 4, 2012 .