Star profile
Theta Circinus
Variable starWhat is Theta Circinus
Theta Circini is a hot blue Be-type star, a Gamma Cassiopeiae variable whose brightness oscillates between magnitudes 4.86 and 5.13 over very short cycles of six and a half hours. It shines from more than fifteen hundred light-years away in the southern Compasses, a constellation Lacaille fixed in the eighteenth century right next to the foot of Centaurus. Its true luminosity exceeds two thousand suns, but distance dims it until it barely registers to the unaided eye.
Where it is and when to see it
Theta Circinus lies in the southern celestial hemisphere. It is visible to the naked eye under a dark sky. Its best month of the year is May: 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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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 Theta Circinus
- Constellation
- Circinus
- Apparent magnitude
- 5.08
- Distance
- 1510.2 light years
- Coordinates (J2000)
- RA 224.183° · Dec -62.781°
- Catalogue
- HIP 73129 · HD 131492
A symbolic commemorative gift: neither the signature nor the chosen name implies ownership of the star or recognition by the IAU.
Other stars in Circinus
Circinus has 21 stars in Stelvia's catalogue. Here are a few of them.
- Alpha Circinus3.18
- Beta Circinus4.07
- Gamma Circinus4.48
- Epsilon Circinus4.85
- Delta Circinus5.04
- Eta Circinus5.16
- HIP 730365.18
- HIP 721315.36