Open cluster · Ophiuchus
IC 4665 Summer Beehive Cluster
mag 4.225′ across
About
IC 4665, the Summer Beehive Cluster, is an open cluster of magnitude 4.2 in Ophiuchus, about 25′ across.
How to find it
- IC 4665 is in the constellation Ophiuchus.
- 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 north of 74° 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 hazy patch or a knot of faint stars 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 4665 |
|---|---|
| Type | Open cluster |
| Magnitude | 4.2The smaller the number, the brighter. |
| Apparent size | 25′the full Moon is 31′ across |
| Constellation | Ophiuchus |
| Right ascension (J2000) | 17h 46m 27.2s |
| Declination (J2000) | +05° 38′ 55″ |
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 →