NGC 5138
Scientific overview
NGC 5138 is an open cluster in the constellation Centaurus. It shines at apparent magnitude 5.33 and spans about 4.2 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 5138
| Distance | 5,959 ly | SIMBAD · catalogued |
| Physical size (major axis) | 7.280142 ly | SIMBAD · derived |
| Radial velocity | -9.6 ± 0.57 km/s | SIMBAD · measured |
| Right ascension (ICRS) | 201.829167 deg | SIMBAD · measured |
| Declination (ICRS) | -59.023333 deg | SIMBAD · measured |
Full field-level provenance
- Distance: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · mesDistance · dist · 2021A&A...651A.104P · distance indicator: paral · catalogued value · source value 1827 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 · 2017AstBu..72..257L · direct catalogue measurement · retrieved 2026-07-11
- Right ascension (ICRS): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · ra · 2020A&A...633A..99C · direct catalogue measurement · retrieved 2026-07-11
- Declination (ICRS): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · dec · 2020A&A...633A..99C · 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 Centaurus
| Object | Type | Mag | Size (′) |
|---|---|---|---|
| lam Cen Nebula | Cluster with nebulosity | 4.5 | 7.2 |
| Pearl ClusterC 97 · NGC 3766 | Open cluster | 5.3 | 6.9 |
| Omega CentauriC 80 · NGC 5139 | Globular cluster | 5.33 | 27 |
| NGC 5662NGC 5662 | Open cluster | 5.5 | 8.1 |
| NGC 5460NGC 5460 | Open cluster | 5.6 | 13.2 |
| NGC 5281NGC 5281 | Open cluster | 5.9 | 6.9 |
| NGC 5316NGC 5316 | Open cluster | 6 | 9.9 |
| NGC 5617NGC 5617 | Open cluster | 6.3 | 5.1 |
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.