Atlas (star)
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Double star Atlas |
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| Pleiades: Left Atlas | |||||||||||||||||||
| AladinLite | |||||||||||||||||||
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Observation dates equinox : J2000.0 , epoch : J2000.0 |
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| Constellation | bull | ||||||||||||||||||
| Right ascension | 03 h 49 m 9.74 s | ||||||||||||||||||
| declination | + 24 ° 03 ′ 12.3 ″ | ||||||||||||||||||
| Apparent brightness | 3.63 (3.84 / 5.52) mag | ||||||||||||||||||
| Typing | |||||||||||||||||||
| B − V color index | (–0.09) | ||||||||||||||||||
| U − B color index | (−0.36) | ||||||||||||||||||
| R − I index | (−0.06) | ||||||||||||||||||
| Spectral class | B8 III + B8 V | ||||||||||||||||||
| Variable star type | SPB | ||||||||||||||||||
| Astrometry | |||||||||||||||||||
| Radial velocity | (8.5 ± 2) km / s | ||||||||||||||||||
| parallax | (8.43 ± 0.56) mas | ||||||||||||||||||
| distance | (387 ± 24) ly (119 ± 7) pc |
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| Visual absolute brightness M vis | −1.75 mag | ||||||||||||||||||
| Proper movement | |||||||||||||||||||
| Rec. Share: | (21,761 ± 1,188) mas / a | ||||||||||||||||||
| Dec. portion: | (−46.241 ± 0.983) mas / a | ||||||||||||||||||
| Physical Properties | |||||||||||||||||||
| Dimensions | (4.74 ± 0.25 / 3.42 ± 0.25) M ☉ | ||||||||||||||||||
| radius | (7.9 ± 0.8 / 3.2 ± 0.3) R ☉ | ||||||||||||||||||
| Effective temperature | (13446 ± 218/13660) K. | ||||||||||||||||||
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Other names and catalog entries |
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Atlas is the proper name of the star 27 Tauri in the Pleiades . The name comes from the titan Atlas of Greek mythology . Like all stars in the Pleiades, Atlas is occasionally covered by the moon .
The star is a spectroscopic binary star . The system has an apparent magnitude of +3.6 mag and is about 390 light years from Earth.
properties
The significantly brighter component of the Atlas Aa1 system has the spectral class B8 III, so the star is a blue giant . In addition, this star is probably changeable and belongs to the star class of slowly pulsating B stars .
The companion Atlas Aa2 seems to be a main sequence star with spectral type B8 V. Its apparent brightness would also be strong enough with about 5.5 to be recognized by the naked eye, but it is outshone by its brighter companion and is therefore only noticeable spectroscopically .
Web links
- Atlas in Jim Kaler's star catalog
Individual evidence
- ↑ a b c d e Gaia data release 2 ( Gaia DR2 ), April 2018
- ↑ a b c d 27 Tau. In: SIMBAD . Center de Données astronomiques de Strasbourg , accessed on July 21, 2018 .
- ↑ a b NSV 1345. In: VSX. AAVSO, accessed July 21, 2018 .
- ↑ a b c TR White, BJS Pope, V. Antoci, PI Pápics, C. Aerts, DR Gies, K. Gordon, D. Huber, GH Schaefer, S. Aigrain, S. Albrecht, T. Barclay, G. Barentsen , PG Beck, TR Bedding, M. Fredslund Andersen, F. Grundahl, SB Howell, MJ Ireland, SJ Murphy, MB Nielsen, V. Silva Aguirre, PG Tuthill: Beyond the Kepler / K2 bright limit: Variability in the seven brightest members of the Pleiades . In: Monthly Notices of the Royal Astronomical Society . 471, No. 3, 2017, pp. 2882–2901. arxiv : 1708.07462 . bibcode : 2017MNRAS.471.2882W . doi : 10.1093 / mnras / stx1050 .