Rosette A
Nebula in Monoceros · 5,000 light-years
🔭 Explore Rosette A in the 3D map →View Rosette A images →| Type | Nebula |
|---|---|
| Constellation | Monoceros |
| Right ascension | 6h 30m 55s |
| Declination | +5° 03′ |
| Object distance | 5,000 light-years |
| Apparent size | 80′ (arc-minutes) |
| Approx. true diameter | 116.4 light-years across |
| Also known as | C49 · NGC 2237 |
Caldwell 49, popularly known as the Rosette A, is a nebula (NGC 2237) in Monoceros — a luminous cloud of interstellar gas and dust. It appears as number 49 in the Caldwell catalogue, Sir Patrick Moore's 1995 list of 109 bright deep-sky objects for amateur astronomers. It spans roughly 80 arc-minutes on the sky. It is one of the showpiece objects Sir Patrick Moore chose for his Caldwell list of bright targets the Messier catalogue left out.
Although it appears about 80′ wide on the sky, its real span is roughly 116.4 light-years — the difference is a measure of how far away it lies.
Observing Rosette A
Rosette A lies in the constellation Monoceros and is best placed in the evening sky around December. Its maximum altitude above the horizon depends on your latitude. Lying near the celestial equator, it can be seen from both hemispheres. Note that the listed magnitude is spread across the whole object — diffuse galaxies and nebulae are often harder to see than the number alone suggests, so dark, moonless skies help a great deal.
See Rosette A in Universe Finder
Open the interactive 3D map to fly to Rosette A and see it in context among the real stars around it. Launch the 3D view →
Sources
- Position, magnitude and angular size from the OpenNGC catalogue (Mattia Verga).
- Object identity cross-referenced with SIMBAD (CDS, Strasbourg).
- Image credits and the original observation source are linked with each photograph.
Related objects
- Orion Nebula — nebula
- Ring Nebula — nebula
- Eagle Nebula — nebula
- Carina Nebula — nebula
- Lagoon Nebula — nebula