Adhara
Double star Adhara |
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Observation dates equinox : J2000.0 , epoch : J2000.0 |
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AladinLite | |||||||||||||||||||||||||||||
Constellation | Big dog | ||||||||||||||||||||||||||||
Astrometry | |||||||||||||||||||||||||||||
Radial velocity | (+27.3 ± 0.9) km / s | ||||||||||||||||||||||||||||
parallax | (7.57 ± 0.57) mas | ||||||||||||||||||||||||||||
Individual data | |||||||||||||||||||||||||||||
Names | A; B. | ||||||||||||||||||||||||||||
Observation data: | |||||||||||||||||||||||||||||
Right ascension | A. | 6 h 58 m 37.5 s | |||||||||||||||||||||||||||
B. | 6 h 58 m 37.7 s | ||||||||||||||||||||||||||||
declination | A. | −28 ° 58 ′ 19.5 ″ | |||||||||||||||||||||||||||
B. | −28 ° 58 ′ 24 ″ | ||||||||||||||||||||||||||||
Apparent brightness | A. | 1.5 mag | |||||||||||||||||||||||||||
B. | |||||||||||||||||||||||||||||
Typing: | |||||||||||||||||||||||||||||
Spectral class | A. | B2 Iab: | |||||||||||||||||||||||||||
Physical Properties: | |||||||||||||||||||||||||||||
radius | A. | (10.7 ± 1.5) R ☉ | |||||||||||||||||||||||||||
B. | |||||||||||||||||||||||||||||
Other names and catalog entries |
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Adhara is the name of the star ε (epsilon) Canis Maioris in the constellation Big Dog . The name (from arab.عذارى, DMG ʿaḏārā ) means "(the) virgins". He is one of the bright giants .
Adhara is a binary star system 470 light years away. The main star has an apparent brightness of +1.5 m and belongs to the spectral class B2. The +7.5 m bright companion star (the absolute brightness is -5 M ) is located at an angular distance of 7.5 " at a position angle of 161 degrees from the main rating.
Despite the relatively large angular distance, the system can only in large telescopes into individual stars be resolved because the main star outshines the approximately 250 times weaker companion to a high degree.
4 to 5 million years ago, Adhara was less than 40 light years from Earth and one of the brightest stars in the night sky . With an apparent brightness of -4 m , the star shone as brightly as Venus .
See also
Web links
Individual evidence
- ↑ JMMC Stellar Diameters Catalog - JSDC (Lafrasse +, 2010) (calculated from the data values LDD and Plx)