Star profile
Sigma Geminorum
Variable starWhat is Sigma Geminorum
σ Geminorum is an inseparable pair 125 light-years away, in the Twins. Its visible component is an orange giant ten times the Sun's size, mottled with vast dark spots like our sunspots but on another scale. It rotates in tidal lock with an invisible companion every 19.6 days: an RS Canum Venaticorum variable whose face slowly shifts as it dances.
Where it is and when to see it
Sigma Geminorum lies in the northern celestial hemisphere. It is visible to the naked eye under a dark sky. Its best month of the year is January: 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 Sigma Geminorum
- Constellation
- Gemini
- Apparent magnitude
- 4.23
- Distance
- 125.1 light years
- Coordinates (J2000)
- RA 115.828° · Dec 28.884°
- Catalogue
- HIP 37629 · HD 62044
A symbolic commemorative gift: neither the signature nor the chosen name implies ownership of the star or recognition by the IAU.
Other stars in Gemini
Gemini has 74 stars in Stelvia's catalogue. Here are a few of them.
- PolluxBeta Geminorum1.16
- CastorAlpha Geminorum1.58
- AlhenaGamma Geminorum1.93
- Nu Geminorum4.13
- 1 Geminorum4.16
- Rho Geminorum4.16
- Tau Geminorum4.41
- 30 Geminorum4.49