Globular cluster · Ara
NGC 6397
Also known as: C86
mag 5.215′ across
About
NGC 6397 is a globular cluster of magnitude 5.2 in Ara, about 15′ across.
How to find it
- NGC 6397 is in the constellation Ara.
- Best evenings: around early August 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 26° 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
- EyesAt the limit of vision from a very dark site, like a faint fuzzy star.
- Binoculars (10×50)A fuzzy ball, brighter towards the middle.
- Telescope (6–8 inch)Resolves into a swarm of stars at medium power, with a dense core.
For a dark country sky with no Moon. From a city, faint galaxies and nebulae can disappear completely.
Facts
| Designations | NGC 6397, C86 |
|---|---|
| Type | Globular cluster |
| Magnitude | 5.2The smaller the number, the brighter. |
| Apparent size | 15′the full Moon is 31′ across |
| Surface brightness | ≈ 19.8 mag/arcsec²Estimate from the magnitude and size, per square arcsecond. |
| Constellation | Ara |
| Right ascension (J2000) | 17h 40m 41.4s |
| Declination (J2000) | −53° 40′ 25″ |
More in Ara
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 →