Alfirk (β Cep)
Alfirk (β Cep) is a double star in the constellation Cepheus, magnitude 3.2.
The prototype of the Beta Cephei variable stars, with a faint companion. Its components (magnitudes 3.2 and 8.6) lie 13.5″ apart at PA 248° (measured 2024).
When and where to see it
It is best placed in the evening sky around September, when it crosses the meridian at about 10 pm local time (around midnight in August). It can be seen from everywhere north of 19°S and never sets north of 19°N.
At its highest it stands 69° up from 50°N, 54° up from 35°N, 19° up from the equator, below the horizon from 35°S.
Facts
- Type
- Double star
- Constellation
- Cepheus
- Designations
- β Cep, Beta Cephei, 8 Cep, 8 Cephei, STF 2806, HIP 106032
- Magnitude
- 3.2
- Position
- RA 21h 28.7m, Dec +70° 34′ (J2000)
Open AstroPilot to see when Alfirk (β Cep) is highest tonight from your location, how easy it is with your telescope or binoculars, and an eyepiece view.