M 46 Deep sky · Open cluster in Puppis · M 46 · NGC 2437
M 46
A rich open cluster in Puppis with a planetary nebula seemingly caught inside — though the nebula is a chance alignment, much nearer to us.
Save the chart (SVG) Tactile chart (A4 SVG)
- Type
- Open cluster
- Designations
- M 46 · NGC 2437
- Constellation
- Puppis
- Apparent magnitude
- 6.1
- Apparent size
- 20′
- Position (J2000)
- RA 07h 42m · Dec −14° 49′
The full Moon, about 31′ across, is 1.6 times as wide. The Sun comes no nearer to it than 36°, around late July, so it is never lost in the Sun’s glare, which reaches about 15° out.
When to see it
On the night of Wed 13 Jan 2027, when it is highest around midnight, on each city’s own clock:
| From | Rises | Highest | Sets |
|---|---|---|---|
| London GMT | 19:29 | 00:10 · 24° | 04:51 |
| New York EST | 18:58 | 00:05 · 34° | 05:11 |
| Singapore GMT+8 | 19:18 | 01:15 · 74° | 07:13 |
| Sydney GMT+11 | 18:26 | 01:06 · 71° | 07:46 |
Common questions
- Can I see it from 50° north?
- Yes. It rises and sets, and at its highest it stands 25° up in the south.
- Can I see it from 35° south?
- Yes. It rises and sets, and at its highest it stands 70° up in the north.
- When is the best time of year to see it?
- Around mid January, when it stands opposite the Sun and is highest at midnight. It comes round about two hours earlier each month, so by mid April it is highest in the early evening, and in mid October not until the hours before dawn.
- Naked eye, binoculars or telescope?
- The naked eye, from a dark country sky, which shows stars to about magnitude 7.0; from a city, binoculars.
Look for
It sits beside the brighter, looser M 47, and the pair fits in one binocular field east of Sirius. A telescope shows the small ring, NGC 2438, on its edge.
Look for
From 50° north it climbs to 25°; from 35° north it climbs to 40°; from the equator it climbs to 75°; from 35° south it climbs to 70°.
Look for
Magnitude 6.1 against the faintest star each can show: the eye under a city sky, 4.5 (1.6 short); the eye under a dark country sky, 7.0 (0.9 to spare); 50 mm binoculars under that dark sky, 11.0 (4.9 to spare); a 100 mm telescope there, 12.5 (6.4 to spare). Through 7×50 binoculars, whose field is about 7.1° across, it spans 5% of the field’s width; through a 100 mm telescope at 50×, a field about 1° across, it spans 33% of the field’s width.