Star profile
21 Cassiopeiae
Variable starWhat is 21 Cassiopeiae
21 Cassiopeiae is a white A-type variable 303 light-years away, set into the starry W of Cassiopeia —one of the easiest figures to spot in the northern sky. Its brightness wavers slightly, marked by internal pulsations. The constellation, lying across the Milky Way, offers any observer a dense backdrop of stars and clusters.
Where it is and when to see it
21 Cassiopeiae lies in the northern celestial hemisphere. It is visible to the naked eye under a dark sky. Its best month of the year is November: the Sun sits at the opposite point of the sky and the star culminates around midnight. How high it climbs above the horizon depends on the latitude you watch from.
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The signature wall
Stelvia's sky works like a signature wall: anyone can leave their name and a message on a real star, and that signature goes up on the map for everyone to read. Signing is free.
A signature without a lock can be replaced by someone else's. The lock makes the signature permanent and lets you choose a symbolic name for the star, always shown next to the star's catalogue identifier. How the lock works
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A public signature from a real person. The chosen name is a symbolic denomination within Stelvia, with no official standing or IAU recognition: the sky is not for sale and belongs to no one.
Astronomical data for 21 Cassiopeiae
- Constellation
- Cassiopeia
- Apparent magnitude
- 5.64
- Distance
- 303.4 light years
- Coordinates (J2000)
- RA 11.413° · Dec 74.988°
- Catalogue
- HIP 3572 · HD 4161
A symbolic commemorative gift: neither the signature nor the chosen name implies ownership of the star or recognition by the IAU.
Other stars in Cassiopeia
Cassiopeia has 93 stars in Stelvia's catalogue. Here are a few of them.
- CihGamma Cassiopeiae2.15
- SchedarAlpha Cassiopeiae2.24
- CaphBeta Cassiopeiae2.28
- HIP 24975.59
- 53 Cassiopeiae5.59
- HIP 83625.63
- HIP 34785.66
- 2 Cassiopeiae5.68