File:Eridanus_constellation_map.svg · Wikimedia Commons · See Wikimedia Commons
Achernar
Sign in to saveAchernar is the brightest star in the constellation of Eridanus and the ninth-brightest in the night sky. It has the Bayer designation Alpha Eridani, which is Latinized from α Eridani and abbreviated Alpha Eri or α Eri. The name Achernar applies to the primary component of a binary system. The two components are designated Alpha Eridani A (the primary) and B (the secondary), with the latter known informally as Achernar B. As determined by the Hipparcos astrometry satellite, this system is located at a distance of approximately from the Sun.
Achernar is the ninth-brightest star visible in Earth's night sky and the brightest star in the constellation Eridanus, formally designated as Alpha Eridani. It is actually a binary system with two components, with the primary star being the one commonly referred to as Achernar.
AI-generated from the Wikipedia summary — may contain errors.
Astronomical data · SIMBAD
- Object type
- Be*
- Spectral type
- B6Vpe
- Distance
- 139 light-years
- Redshift
- z = 0.000028253277987166925
- Coordinates
- RA 24.4285° · Dec -57.2368°
via SIMBAD · CDS Strasbourg
Wikidata facts
- Official name
- Achernar
- Distance from Earth
- 43
- Radius
- 7.3
- Mass
- 6.7
- Image
- Position Alpha Eri.png
Show 17 more facts
- Commons category
- Achernar
- spectral class
- B5
- catalog code
- ALS 16724
- stellar rotational velocity
- 260
- apparent magnitude
- 0.88
- effective temperature
- 20230
- surface gravity
- 4000
- right ascension
- 24.428522833
- declination
- -57.236752806
- parallax
- 22.68
- radial velocity
- 19.0
- luminosity
- 1076
- flattening
- 0.75
- right ascension component of proper motion
- 92
- declination component of proper motion
- -34
- age estimated by a dating method
- 37.3
- absolute magnitude
- -2.77
Sources (8)
via Wikidata · CC0
~7 min read
Article
8 sectionsContents
- Nomenclature
- Namesake
- Properties
- Co-moving companion
- Historical visibility
- Notes
- References
- Further reading
Achernar is the brightest star in the constellation of Eridanus and the ninth-brightest in the night sky. It has the Bayer designation Alpha Eridani, which is Latinized from α Eridani and abbreviated Alpha Eri or α Eri. The name Achernar applies to the primary component of a binary system. The two components are designated Alpha Eridani A (the primary) and B (the secondary), with the latter known informally as Achernar B. As determined by the Hipparcos astrometry satellite, this system is located at a distance of approximately from the Sun.
Of the ten brightest stars in the night-time sky by apparent magnitude, Alpha Eridani is the hottest and bluest in color because it is spectral type B. Achernar has an unusually rapid rotational velocity, causing it to become oblate in shape. The secondary is smaller, is spectral type A, and orbits Achernar at a distance of .