Open cluster · Serpens
IC 4756 Graff's Cluster
mag 4.624′ across
About
IC 4756, the Graff's Cluster, is an open cluster of magnitude 4.6 in Serpens, about 24′ across.
How to find it
- IC 4756 is in the constellation Serpens.
- Best evenings: around mid-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 north of 75° S.
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
- EyesA faint smudge at the limit of vision, only from a dark site.
- Binoculars (10×50)A rich scattering of stars — binoculars often give the best view.
- Telescope (6–8 inch)Dozens of stars, many sharp and some coloured.
For a dark country sky with no Moon. From a city, faint galaxies and nebulae can disappear completely.
Facts
| Designations | IC 4756 |
|---|---|
| Type | Open cluster |
| Magnitude | 4.6The smaller the number, the brighter. |
| Apparent size | 24′the full Moon is 31′ across |
| Constellation | Serpens |
| Right ascension (J2000) | 18h 38m 51.5s |
| Declination (J2000) | +05° 27′ 44″ |
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 →