Capricornus constellation
Capricornus (the Sea Goat) is a constellation in the southern sky, best seen in the evening in September. Its brightest star is Deneb Algedi (magnitude 2.87). Capricornus covers 414 square degrees and is the 40th-largest of the 88 constellations.
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How to find Capricornus, step by step
Follow Vega through Altair.
- On late summer evenings find Vega overhead and Altair to the south of it.
- Continue the line from Vega through Altair about as far again toward the southern horizon.
- You reach Algedi and Dabih, the horns of the sea goat; the faint stars of Capricornus form a large, flat triangle below them.
Detailed star map of Capricornus
Facts
| Latin name | Capricornus (genitive: Capricorni) |
|---|---|
| Abbreviation | Cap |
| Meaning | the Sea Goat |
| Area | 414 square degrees (40th of 88) |
| Location | right ascension 21.0 h, declination −18° |
| Visible from | latitudes 62° N to 90° S (whole constellation) |
| Best month | September (at about 9 pm) |
| Brightest star | Deneb Algedi |
| Stars brighter than magnitude 6 | 48 |
| Named stars (IAU) | 5 |
| Messier objects | M30 |
| Neighbors | Aquila, Aquarius, Microscopium, Piscis Austrinus, Sagittarius |
How to find Capricornus
From 40° N (the USA, southern Europe, Japan) look south in September evenings: at about 9 pm Capricornus stands highest, around 32° above the southern horizon. From 35° S (Australia, South Africa, Argentina) it is highest in the north, about 73° above the horizon. The months before and after (August and October) are also good: then it is up a couple of hours earlier or later.
Capricornus borders Aquila, Aquarius, Microscopium, Piscis Austrinus and Sagittarius.
Stars of Capricornus
Capricornus has 48 stars brighter than magnitude 6, the limit of the naked eye under a dark sky. These are the brightest:
| Star | Designation | Magnitude | Type | Distance |
|---|---|---|---|---|
| Deneb Algedi | δ Capricorni | 2.87 | Am | 44 ly |
| Dabih | β Capricorni | 3.08 | F8V+A0 | 555 ly |
| Algedi | α2 Capricorni | 3.57 | G8IIIb | 109 ly |
| Nashira | γ Capricorni | 3.68 | F0p | 171 ly |
| — | ζ Capricorni | 3.74 | G4Ib | — |
| — | θ Capricorni | 4.07 | A1V | — |
| — | ω Capricorni | 4.11 | M0-III-IIIbBa0.2 | — |
| — | ψ Capricorni | 4.14 | F4V | — |
| — | α1 Capricorni | 4.24 | G3Ib | — |
| — | ι Capricorni | 4.28 | G7IIIFe-1.5 | — |
| — | 24 Capricorni | 4.5 | M0.5III | — |
Deep-sky objects in Capricornus
Capricornus contains one object from Charles Messier's catalog:
- Messier 30 (M30): globular cluster, 7.1 mag
Printable Capricornus map and outline
A black and white version for printing and a plain outline of the Capricornus figure, useful for school projects, worksheets and learning to recognize the shape.
History
Capricornus is one of the 48 constellations listed by Ptolemy in the Almagest (2nd century AD). Its official boundary was drawn by Eugène Delporte for the International Astronomical Union in 1930.
Questions about Capricornus
What is the brightest star in Capricornus?
Deneb Algedi, at magnitude 2.87, about 44 light-years away.
When can you see Capricornus?
Capricornus is best seen in the evening in September. The whole constellation is visible from latitudes between 62° N and 90° S.
How many stars are in Capricornus?
48 stars in Capricornus are brighter than magnitude 6 and can be seen with the naked eye under a dark sky; 5 of them have official IAU names.
What does Capricornus mean?
Capricornus means “the Sea Goat” in Latin. Its abbreviation is Cap and the genitive, used in star names such as δ Capricorni, is Capricorni.
