Globular cluster
NGC 6397 (NGC6397)
In Ara (Ara) • Magnitude 5.2 • 15 arcminutes
Open the free AstroPlanner with NGC 6397 pre-selected, scored against your telescope, location, and the live cloud forecast.
A nearby southern globular cluster in Ara.
NGC 6397 at a glance
| Catalog IDs | N 6397 |
| Type | Globular cluster |
| Constellation | Ara (Ara) |
| Right ascension | 17h 40m 42s |
| Declination | -53° 40' 25" |
| Apparent magnitude | 5.20 |
| Surface brightness | 19.8 mag/arcsec² |
| Angular size | 15.3 × 15.3 arcmin |
| Max altitude at 45°N | Below horizon |
| Best imaging months | May, Jun, Jul |
How to image NGC 6397
NGC 6397 sits in the constellation Ara at right ascension 17h 40m 42s and declination -53° 40' 25". To frame and integrate it well, AstroPlanner will compute the optimal moonless window for tonight from your location, the field-of-view fit against your sensor and focal length, the suggested total integration time given your aperture and sky Bortle class, and a cloud-aware schedule that drops it from the plan if your nearest cloud forecast spike overlaps the best altitude window.