Star profile
21 Herculis
What is 21 Herculis
21 Herculis shines about 366 light-years away within the great summer hero. A-type, white and hot, it keeps the clean, youthful look of its spectral class. Compared with the Sun, its light arrives slightly bluer and more intense per unit of surface. One more small torch along the long body of Hercules stretched across the sky.
Where it is and when to see it
21 Herculis lies in the northern 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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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 21 Herculis
- Constellation
- Hercules
- Apparent magnitude
- 5.83
- Distance
- 366.5 light years
- Coordinates (J2000)
- RA 246.045° · Dec 6.948°
- Catalogue
- HIP 80351 · HD 147869
A symbolic commemorative gift: neither the signature nor the chosen name implies ownership of the star or recognition by the IAU.
Other stars in Hercules
Hercules has 136 stars in Stelvia's catalogue. Here are a few of them.
- KornephorosBeta Herculis2.78
- RasalgethiAlpha 1 Herculis2.78
- Zeta Herculis2.81
- 100 Herculis5.79
- HIP 911185.79
- HIP 903425.81
- HIP 812895.83
- 77 Herculis5.83