NGC 2244 — Open Cluster in Monoceros
About NGC 2244
Description
NGC 2244 is the bright open cluster at the center of the Rosette Nebula (C49) in Monoceros, about 5,200 light-years away. It contains about 16 hot, luminous OB-type stars arranged in a rectangular pattern, spanning about 24 arcminutes.
Observing Tips
An easy and attractive cluster even without the nebula. Binoculars show several bright stars in a distinctive rectangle. A telescope at 30-50x frames it nicely. To see the surrounding Rosette Nebula, add an OIII filter. Best in winter.
History
Discovered by John Flamsteed around 1690. The cluster is only about 2 million years old and its massive stars are responsible for illuminating and sculpting the Rosette Nebula.
Fun Facts
The most massive star in NGC 2244 is the O5 star HD 46223, which is about 50 times more massive than the Sun and 400,000 times as luminous. These stars will end their lives as supernovae within the next few million years.
Observe
1Properties
Position & Identifiers
2How easy to spot?
| Telescope | Bortle 3 | Bortle 4 | Bortle 5 |
|---|---|---|---|
| 80 mm refractor 80mm refr. | Easy | Easy | Easy |
| 150 mm Newton 150mm Newt. | Easy | Easy | Easy |
| Celestron C8 (203 mm SCT) C8 203mm | Easy | Easy | Easy |
Bortle 3 = rural · 4 = outer suburbs · 5 = suburbs
3Visibility
Set a location in User Settings to see visibility data.
4
Eyepiece View
5
Best Magnification
6Where this cluster sits in time
Open clusters span more than four orders of magnitude in age — from newborn OB associations to ancient, metal-rich survivors.
7
Colour-Magnitude Diagram
A cluster's colour-magnitude diagram reveals its age: the bluer the turn-off point where the main sequence bends into red giants, the younger the cluster.
Each point is a Gaia-DR3 member. Colour encodes spectral type; size reflects membership probability.
Explore
8
Classification Decoder
Nearby in the Sky
Other targets within a few degrees — pan your scope a little and keep exploring.
Visibility scores assume a 150 mm Newton at Bortle 4.
Explore Nightbase
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