NGC 2239
Scientific overview
NGC 2239 is a cluster with nebulosity in the constellation Monoceros. It shines at apparent magnitude 4.8 and spans about 9.3 arcminutes of sky.
Observation guide
Guidance follows standard observing practice, derived from the object's real magnitude and position. A dark, moonless sky always helps.
Location in the sky
Precision measurements
Distances and velocities from SIMBAD · NGC 2244
| Distance | 4,253 ly | SIMBAD · catalogued |
| Physical size (major axis) | 11.505686 ly | SIMBAD · derived |
| Radial velocity | 33.62 ± 0.7 km/s | SIMBAD · measured |
| Right ascension (ICRS) | 98.045 deg | SIMBAD · measured |
| Declination (ICRS) | 4.913889 deg | SIMBAD · measured |
Full field-level provenance
- Distance: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · mesDistance · dist · 2019MNRAS.486.5726D · distance indicator: paral · catalogued value · source value 1304 pc · retrieved 2026-07-11
- Physical size (major axis): Centre de données astronomiques de Strasbourg (CDS) · derived (OpenNGC angular size × SIMBAD distance) · physical size = angular size × distance (small-angle); angular size from OpenNGC, distance from SIMBAD mesDistance · derived · retrieved 2026-07-11
- Radial velocity: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · rvz_radvel · 2019A&A...623A..80C · direct catalogue measurement · retrieved 2026-07-11
- Right ascension (ICRS): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · ra · 2021A&A...647A..19T · direct catalogue measurement · retrieved 2026-07-11
- Declination (ICRS): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · dec · 2021A&A...647A..19T · direct catalogue measurement · retrieved 2026-07-11
Physical size is derived from the OpenNGC angular size and the catalogued distance (small-angle: size = angle × distance). This is a Galactic object: its Doppler shift is shown as a radial velocity, not a cosmological redshift. Fields a source did not provide are omitted, never invented.
Other objects in Monoceros
| Object | Type | Mag | Size (′) |
|---|---|---|---|
| Christmas Tree ClusterNGC 2264 | Cluster with nebulosity | 3.9 | 11.4 |
| NGC 2232NGC 2232 | Open cluster | 3.9 | 9.9 |
| M 50M 50 · NGC 2323 | Open cluster | 5.9 | 14.1 |
| Great Bird ClusterNGC 2301 | Open cluster | 6 | 10.2 |
| Rosette NebulaC 49 · NGC 2238 | H II region | 6 | 80 |
| NGC 2343NGC 2343 | Open cluster | 6.7 | 7.5 |
| NGC 2353NGC 2353 | Open cluster | 7.1 | 6.6 |
| NGC 2335NGC 2335 | Open cluster | 7.2 | 8.7 |
Sources
The primary and reference sources this topic draws on.
- OpenNGCOpenNGC (M. Verga) — NGC/IC, Messier, and Caldwell catalogue data
Openly-licensed deep-sky catalogue: object types, positions, magnitudes, sizes, morphology, and cross-identifiers.