Star profile
Eta Hydrae
Variable starWhat is Eta Hydrae
A massive blue star, seven times the Sun and nearly three thousand times more luminous, runs along the long serpentine body of the Water Snake at 587 light-years' distance. Its surface burns above 18,000 degrees; its rotation of around a hundred kilometres per second imprints a faint variable beat that for years left astronomers debating its classification. It is one of those hot, youthful beacons — barely 32 million years old — that pick out, with sharp precision, the serpentine geometry of the largest constellation in the sky.
Where it is and when to see it
Eta Hydrae lies in the northern celestial hemisphere. It is visible to the naked eye under a dark sky. Its best month of the year is February: 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 Eta Hydrae
- Constellation
- Hydra
- Apparent magnitude
- 4.30
- Distance
- 586.7 light years
- Coordinates (J2000)
- RA 130.806° · Dec 3.399°
- Catalogue
- HIP 42799 · HD 74280
A symbolic commemorative gift: neither the signature nor the chosen name implies ownership of the star or recognition by the IAU.
Other stars in Hydra
Hydra has 121 stars in Stelvia's catalogue. Here are a few of them.
- AlphardAlpha Hydrae1.99
- Gamma Hydrae2.99
- Zeta Hydrae3.11
- ZhangUpsilon 1 Hydrae4.11
- Delta Hydrae4.14
- Beta Hydrae4.29
- 12 Hydrae4.32
- Rho Hydrae4.35