Capricornus
Cap · genitive Capricorni · southern sky
At a glance
- Catalogued stars
- 82
- Visible to the eye
- 82 stars
- Brightest star
- Deneb Algedi (2.85)
- Best seen
- August
- Declination span
- -26.9° to -12.5°
- Nearest star
- HD 192310 · 29.1 ly
Visible from everywhere south of about 63°N.
When and where to look for Capricornus
Capricornus crosses the meridian — its highest point in the sky — at local midnight around August, which makes the months from July to September the easiest time to find it in the evening. It spans declinations -26.9° to -12.5°, so visible from everywhere south of about 63°N.
The quickest way to find it is to open the live AR sky map and point your phone at the sky — if Capricornus is above your horizon right now, its figure is drawn in the position it genuinely occupies above you.
Brightest stars in Capricornus
| Star | Mag | Type | Distance |
|---|---|---|---|
| Deneb Algedi49Del Cap | 2.85 | A5mF2 (IV) | 38.7 ly |
| Dabih9Bet Cap | 3.05 | A5:n | 326.8 ly |
| Algedi6Alp2Cap | 3.58 | G6/G8III | 105.8 ly |
| Nashira40Gam Cap | 3.69 | A7III:mp... | 157 ly |
| 34Zet Cap | 3.77 | G4Ibp... | 385.5 ly |
| 23The Cap | 4.08 | A1V | 162.2 ly |
Magnitude runs backwards: lower numbers are brighter, and anything below about 6.5 is beyond the naked eye under a dark sky.
What Capricornus is made of
The catalogue lists 82 stars within Capricornus, of which 82 are magnitude 6.5 or brighter — the limit of what an unaided eye picks up under a genuinely dark sky. The rest need binoculars or a telescope.
Spectral make-up
Spectral class is a temperature ordering, running from O at around 30,000 K down to M below 3,500 K. A constellation is a direction, not a group, so this is simply what happens to lie along that line of sight.
The closest catalogued star in this direction is HD 192310 at 29.1 light years. The most distant is HD 191639 at roughly 2,330 light years — stars that appear side by side here are nothing of the sort.