Star profile
47 Hydrae
Hot blue starWhat is 47 Hydrae
47 Hydrae is a blue B-type star kindled along the long body of Hydra, the largest constellation in the sky. From 333 light-years away, its magnitude 5.2 hides a body far hotter and more luminous than the Sun, able to ionise the surrounding gas with its ultraviolet output. The light arriving tonight set out in the late 17th century, contemporary with Rømer's first precise measurements of the speed of light.
Where it is and when to see it
47 Hydrae lies in the southern celestial hemisphere. It is visible to the naked eye under a dark sky. Its best month of the year is April: 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 47 Hydrae
- Constellation
- Hydra
- Apparent magnitude
- 5.20
- Distance
- 332.9 light years
- Coordinates (J2000)
- RA 209.630° · Dec -24.972°
- Catalogue
- HIP 68269 · HD 121847
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
- HIP 563325.13
- 54 Hydrae5.15
- HIP 570475.20
- HIP 532525.23
- 56 Hydrae5.23