Mirfak
Star Mirfak (α Persei) |
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Finding Mirfak in the sky | |||||||||||||||||||
AladinLite | |||||||||||||||||||
Observation dates equinox : J2000.0 , epoch : J2000.0 |
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Constellation | Perseus | ||||||||||||||||||
Right ascension | 03 h 24 m 19.37 s | ||||||||||||||||||
declination | + 49 ° 51 ′ 40.3 ″ | ||||||||||||||||||
Apparent brightness | 1.79 likes | ||||||||||||||||||
Typing | |||||||||||||||||||
B − V color index | +0.48 | ||||||||||||||||||
U − B color index | +0.37 | ||||||||||||||||||
R − I index | +0.33 | ||||||||||||||||||
Spectral class | F5 Ib | ||||||||||||||||||
Astrometry | |||||||||||||||||||
Radial velocity | (−2.0 ± 0.1) km / s | ||||||||||||||||||
parallax | (6.44 ± 0.17) mas | ||||||||||||||||||
distance | (506 ± 13) ly (155.3 ± 4.1) pc |
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Visual absolute brightness M vis | approx. −4.2 mag | ||||||||||||||||||
Proper movement | |||||||||||||||||||
Rec. Share: | (+23.75 ± 0.16) mas / a | ||||||||||||||||||
Dec. portion: | (−26.23 ± 0.15) mas / a | ||||||||||||||||||
Physical Properties | |||||||||||||||||||
Dimensions | 11 M ☉ | ||||||||||||||||||
radius | 56 R ☉ | ||||||||||||||||||
Effective temperature | 6600 K | ||||||||||||||||||
Other names and catalog entries |
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annotation | |||||||||||||||||||
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Mirfak ( α Persei , Alpha Persei ) lies in the center of the constellation Perseus and is its brightest star. Its apparent magnitude is around 1.8, making it one of the 50 brightest stars in the night sky . Mirfak is a yellow supergiant ; its mass is around eleven times that of the sun, its diameter around 56 times that of the sun.
You can easily find Alpha Persei in the sky if you extend the second line of the letter W , which is formed by the constellation Cassiopeia , about five times beyond the star Delta Cassiopeiae - it forms the first angle of the W. Mirfak is part of the five star series . In addition to Mirfak , another proper name is Algenib , which can lead to confusion with the star of the same name in the constellation Pegasus . Both names are of Arabic origin. Mirfak , also written Mirphak , comes from the Arabicالمرفق الثريا / al-mirfaq aṯ-ṯurayyā / 'Elbow of the Pleiades '. Algenib , also Algeneb , Elgenab , Gęnib , Chenib or Alchemb , is derived fromالجنب / al-ǧanb orالجانب / al-ǧānib / 'the flank'.
The IAU Working Group on Star Names (WGSN) established the proper name Mirfak as the standardized proper name for this star on July 20, 2016 .
Web links
- Jim Kaler, Stars , Mirfak
Individual evidence
- ↑ a b c Hipparcos catalog (ESA 1997)
- ↑ a b c Bright Star Catalog
- ↑ Pulkovo radial velocities for 35493 HIP stars
- ↑ a b c Hipparcos, the New Reduction (van Leeuwen, 2007)
- ↑ Bulletin of the IAU Working Group on Star Names, No. 1, July 2016. (PDF) Retrieved November 9, 2016 (English, 184 KiB).