Beta Corvi (β Corvi, abbreviated Beta Crv) is the second-brightest star in the southern constellation of Corvus. It is a blue‑white subgiant star of spectral type B6 IV and is commonly known by the traditional name Kraz.
Nomenclature
- Bayer designation: β Corvi
- Flamsteed designation: 24 Corvi
- Hipparcos catalogue: HIP 75216
- Henry Draper catalogue: HD 108103
Physical characteristics
- Apparent magnitude (V): +2.65, making it readily visible to the naked eye.
- Spectral class: B6 IV, indicating a blue-white star that has evolved off the main sequence into the subgiant phase.
- Effective temperature: approximately 13,600 K.
- Luminosity: ≈ 300 times that of the Sun.
- Radius: ≈ 3.8 solar radii.
- Mass: ≈ 4.5 solar masses.
Distance and motion
- Parallax (Hipparcos/Gaia): ≈ 19.99 mas, corresponding to a distance of about 164 light‑years (≈ 50 parsecs).
- Radial velocity: +8 km s⁻¹ (receding from the Solar System).
- Proper motion: +44.0 mas yr⁻¹ in right ascension, –43.9 mas yr⁻¹ in declination.
Astrophysical context
Beta Corvi lies near the border of the constellations Corvus and Crater. It is not a known variable star and shows no confirmed companions; however, some catalogues list it as a possible spectroscopic binary, although this remains unconfirmed.
Cultural and historical references
- The name “Kraz” is derived from an Arabic term meaning “the bell” or “the hooter”.
- In traditional Chinese astronomy, Beta Corvi is part of the asterism “The Star Cluster” (星團, Xīng Tuán).
Research and observation
Beta Corvi serves as a reference point for calibrating photometric systems due to its stable brightness and well‑characterized spectrum. It has been observed in various spectroscopic surveys aimed at studying the evolution of B‑type subgiants.
See also
- Alpha Corvi (Alchiba) – the brightest star in Corvus.
- List of brightest stars.
References
Data compiled from the Hipparcos and Gaia astrometric catalogues, the Henry Draper Catalogue, and peer‑reviewed astrophysical literature on stellar classification and parameters.
