Alschain
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Triple star Alschain (β Aquilae) |
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| Alschain's position | |||
| Observation data epoch : J2000.0 |
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| AladinLite | |||
| Constellation | Eagle | ||
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Vis. Brightness (total) |
+3.7 mag | ||
| Astrometry | |||
| Radial velocity | (−39.8 ± 0.9) km / s | ||
| distance | 44.7 ly (13.7 pc ) |
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| Proper movement | |||
| Rec. Share: | +46.35 mas / a | ||
| Dec. portion: | −481.35 mas / a | ||
| Individual data | |||
| Names | A, B, C | ||
| Observation data: | |||
| Right ascension | A. | 19 h 55 m 18.79 s | |
| B. | 19 h 55 m 18.8 s | ||
| C. | 19 h 55 m 17.5 s | ||
| declination | A. | + 6 ° 24 ′ 24.3 ″ | |
| B. | + 6 ° 24 ′ 36 ″ | ||
| C. | + 6 ° 26 ′ 01 ″ | ||
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Apparent brightness |
A. | +3.71 m | |
| B. | +11.4 m | ||
| C. | +10.5 m | ||
| Typing: | |||
| Spectral class | A. | G8 IV | |
| B. | M3 V | ||
| C. | |||
| BV color index | A. | +0.86 | |
| B. | |||
| C. | |||
| UB color index | A. | +0.48 | |
| B. | |||
| C. | |||
| Astrometry: | |||
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Absolute visual brightness M vis |
A. | +3.03 mag | |
| B. | +10.7 mag | ||
| C. | +9.8 mag | ||
| Physical Properties: | |||
| Dimensions | A. | 1.3 M ☉ | |
| B. | 0.3 M ☉ | ||
| C. | M ☉ | ||
| radius | A. | 3 R ☉ | |
| B. | R ☉ | ||
| C. | R ☉ | ||
| Luminosity | A. | 6 L ☉ | |
| B. | 0.025 L ☉ | ||
| C. | L ☉ | ||
| Effective temperature | A. | 5300 K | |
| B. | 3400 K | ||
| C. | K | ||
| Designations and catalog entries | |||
| Bayer-Bez. | β Aquilae | ||
| Flamsteed-Bez. | 60 Aquilae | ||
| Bonn diam. | BD + 6 ° 4357 | ||
| Bright Star Cat. | HR 7602 | ||
| HD catalog | HD 188512 | ||
| SAO catalog | SAO 125235 | ||
| Tycho catalog | TYC 493-3355-1 | ||
| Hipparcos catalog | HIP 98036 | ||
| WDS catalog | WDS 19553 + 0624 | ||
| ADS catalog | ADS 13110 | ||
| Other names |
FY 771 | ||
Alschain or Alshain ( Arabic الشاهين, DMG aš-šāhīn , the (wandering) falcon ') is the name of the star Beta Aquilae (β Aquilae, β Aql for short) in the eagle constellation . Although Beta usually denotes the second brightest star in a constellation, Alschain is only the seventh brightest star in the eagle. It has an apparent magnitude of +3.71 mag and is an orange sub-giant of the spectral class G8. Its distance is 45 light years; so Alschain is a relatively close star. It has 1.3 times the solar mass and about three times the solar radius. The hydrogen-burning phase in its core is over and it will "soon" become a bright red giant . Slight fluctuations in brightness of Alschain with an amplitude of about 0.05 mag could be detected. He is also a multiple star . A red dwarf of the spectral class M3 and apparent magnitude of +11.4 mag orbits it at a distance of 12.8 " . This companion is faint and has only 0.3 solar masses, but will exist much longer than the main component. A third companion of the apparent Brightness of +10.5 mag orbits the central star at a distance of 175 ".