Open cluster · Crux
NGC 4103 The Longtail
mag 7.47.8′ across
About
NGC 4103 (The Longtail) is an open cluster of magnitude 7.4 in Crux, about 7.8′ across.
How to find it
- NGC 4103 is in the constellation Crux.
- Best evenings: around early May it is highest at about 9 pm (10 pm in summer time); a month earlier, two hours later.
- Where on Earth: it is seen well, at least 10° up, from south of 19° N.
When it rises and sets tonight, how high it climbs and how much the Moon gets in the way are worked out in your browser for your place.
What you will see
- EyesNot visible to the naked eye.
- Binoculars (10×50)A small knot of stars, partly resolved.
- Telescope (6–8 inch)A group of faint stars.
For a dark country sky with no Moon. From a city, faint galaxies and nebulae can disappear completely.
Facts
| Designations | NGC 4103 |
|---|---|
| Type | Open cluster |
| Magnitude | 7.4The smaller the number, the brighter. |
| Apparent size | 7.8′the full Moon is 31′ across |
| Constellation | Crux |
| Right ascension (J2000) | 12h 06m 39.6s |
| Declination (J2000) | −61° 15′ 00″ |
Sources and credits
Catalog data: OpenNGC by Mattia Verga, CC BY-SA 4.0, and d3-celestial by Olaf Frohn, BSD 3-Clause. All data sources →