Star profile
31 Orionis
Variable starWhat is 31 Orionis
31 Orionis —also catalogued as CI Orionis for its variability— is a K5III orange giant set just north of the Hunter's belt. Astronomers detected slow oscillations hinting at a 141-day cycle, though the General Catalogue still treats it as a whisper awaiting confirmation. With a faint companion ten magnitudes dimmer 12.7 arcseconds away, it offers an intimate contrast: a mature ember beside a distant spark, both suspended in the same view of Orion.
Where it is and when to see it
31 Orionis lies in the southern celestial hemisphere. It is visible to the naked eye under a dark sky. Its best month of the year is December: 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 31 Orionis
- Constellation
- Orion
- Apparent magnitude
- 4.71
- Distance
- 508.1 light years
- Coordinates (J2000)
- RA 82.433° · Dec -1.092°
- Catalogue
- HIP 25737 · HD 36167
A symbolic commemorative gift: neither the signature nor the chosen name implies ownership of the star or recognition by the IAU.
Other stars in Orion
Orion has 128 stars in Stelvia's catalogue. Here are a few of them.
- RigelBeta Orionis0.18
- BetelgeuseAlpha Orionis0.45
- BellatrixGamma Orionis1.64
- Chi 2 Orionis4.64
- 11 Orionis4.65
- Omicron 1 Orionis4.71
- 22 Orionis4.72
- 56 Orionis4.76