Bubble Nebula
Scientific overview
Bubble Nebula is an H II region in the constellation Cassiopeia. It shines at apparent magnitude 11 and spans about 15 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 7635
| Distance | 8,806 ly | SIMBAD · catalogued |
| Physical size (major axis) | 38.424393 ly | SIMBAD · derived |
| Physical size (minor axis) | 20.49301 ly | SIMBAD · derived |
| Right ascension (ICRS) | 350.20125 deg | SIMBAD · measured |
| Declination (ICRS) | 61.201667 deg | SIMBAD · measured |
Full field-level provenance
- Distance: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · mesDistance · dist · 2025AJ....169..257Z · distance indicator: kin · catalogued value · source value 2.7 kpc · 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
- Physical size (minor 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
- Right ascension (ICRS): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · ra · 1989ApJS...71..469L · direct catalogue measurement · retrieved 2026-07-11
- Declination (ICRS): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · dec · 1989ApJS...71..469L · 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 Cassiopeia
| Object | Type | Mag | Size (′) |
|---|---|---|---|
| Owl ClusterC 13 · NGC 457 | Open cluster | 6.4 | 7.8 |
| IC 1805 | Cluster with nebulosity | 6.5 | 60 |
| IC 1848 | Cluster with nebulosity | 6.5 | 40 |
| NGC 129NGC 129 | Open cluster | 6.5 | 5.4 |
| NGC 654NGC 654 | Open cluster | 6.5 | 6.3 |
| NGC 1027NGC 1027 | Open cluster | 6.7 | 7.8 |
| NGC 7789NGC 7789 | Open cluster | 6.7 | 14.4 |
| M 52M 52 · NGC 7654 | Open cluster | 6.9 | 9.9 |
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.