IC 4996
Scientific overview
IC 4996 is an open cluster in the constellation Cygnus. It shines at apparent magnitude 7.3 and spans about 6 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 · IC 4996
| Distance | 6,928 ly | SIMBAD · catalogued |
| Physical size (major axis) | 12.090876 ly | SIMBAD · derived |
| Radial velocity | 78.51 ± 0.3 km/s | SIMBAD · measured |
| Right ascension (ICRS) | 304.135 deg | SIMBAD · measured |
| Declination (ICRS) | 37.648889 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 2124 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 Cygnus
| Object | Type | Mag | Size (′) |
|---|---|---|---|
| North America NebulaC 20 · NGC 7000 | H II region | 4 | 120 |
| M 39M 39 · NGC 7092 | Open cluster | 4.6 | 19.5 |
| NGC 6871NGC 6871 | Open cluster | 5.2 | 9.3 |
| M 29M 29 · NGC 6913 | Open cluster | 6.6 | 3.6 |
| NGC 6811NGC 6811 | Open cluster | 6.8 | 7.2 |
| Eastern VeilC 33 · NGC 6992 | Supernova remnant | 7 | 60 |
| Eastern VeilNGC 6995 | Supernova remnant | 7 | 12 |
| NGC 7063NGC 7063 | Open cluster | 7 | 6.3 |
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.