Open cluster in Cancer
Beehive Cluster (M44)
The Beehive, and one of the few things here with a practical use: the Greeks watched it to forecast weather, on the reasoning that haze thick enough to hide something this large meant rain was coming. Galileo turned a telescope on it in 1609 and counted more than forty stars where everyone before him had seen a smudge.
It is around six hundred million years old and shares both an age and a direction of travel with the Hyades, which means the two were almost certainly born together and have been separating ever since. About a thousand stars, of which the eye picks up perhaps a dozen and a pair of binoculars fifty.
- Catalogue
- M44
- Type
- Open cluster
- Constellation
- Cancer
- Distance
- 610 light-years
- Apparent magnitude
- 3.1
- Surface brightness
- 21.6 mag/□″
- Apparent size
- 95′
- Right ascension
- 8h 40m
- Declination
- +19.98°
- Found by
- Known since antiquity
Magnitude 3.1 for the cluster as a whole, though that is a sum rather than a thing you see: what reaches you is a scatter of separate stars, and whether you catch it depends on how bright the brightest of them are. Why surface brightness is the number that matters.
Could you see it?
Bright enough for any sky there is, including the middle of a city. One of the few things on this list of which that is true.
| Sky | Eye | 10×50 | 80mm | 130mm | 200mm |
|---|---|---|---|---|---|
| Bortle 1 21.9 mag/□″ | Easy | Easy | Easy | Easy | Easy |
| Bortle 2 21.7 mag/□″ | Easy | Easy | Easy | Easy | Easy |
| Bortle 3 21.4 mag/□″ | Easy | Easy | Easy | Easy | Easy |
| Bortle 4 20.9 mag/□″ | Easy | Easy | Easy | Easy | Easy |
| Bortle 5 20.3 mag/□″ | Easy | Easy | Easy | Easy | Easy |
| Bortle 6 19.3 mag/□″ | Easy | Easy | Easy | Easy | Easy |
| Bortle 7 18.6 mag/□″ | Easy | Easy | Easy | Easy | Easy |
| Bortle 8 18.1 mag/□″ | Easy | Easy | Easy | Easy | Easy |
| Bortle 9 17.8 mag/□″ | Easy | Easy | Easy | Easy | Easy |
At the eyepiece
Too big for most telescopes and perfect for binoculars, where forty or so stars sit in a loose triangular sprawl. Naked-eye it is an obvious patch of haze — which is why every culture with a clear sky noticed it, and why they used it to judge the weather.
When, and from where
Highest in the middle of the night in January. Passes overhead at 20°N and rises from everywhere except the far south — below 70°S it never clears the horizon.
| Latitude | Highest it gets | |
|---|---|---|
| 60°N Oslo, Anchorage | 50° | |
| 51°N London, Calgary | 59° | |
| 40°N New York, Madrid | 70° | |
| 30°N Cairo, Houston | 80° | |
| 0°N the equator | 70° | |
| 33°S Sydney, Cape Town | 37° |
Nearby in the sky
The whole catalogue →Nothing else in the catalogue is especially close; the nearest is 8.5° apart, which is a separate trip rather than a nudge of the tube. Everything below is measured from M44 itself, not from the middle of Cancer.
- M67 Open cluster 8.5° apart Cancer · magnitude 6.1 · binoculars from Bortle 9 or darker
- M48 Open cluster 27° apart Hydra · magnitude 5.8 · binoculars from Bortle 9 or darker
- M95 Galaxy 31° apart Leo · magnitude 9.7 · binoculars from Bortle 4 or darker
- M105 Galaxy 31° apart Leo · magnitude 9.3 · binoculars from Bortle 5 or darker
One of 110. Positions J2000; the sky is the final authority.