Reflection nebula · Eridanus
the Witch Head Nebula
Deep skyNGC 1909
Scientific overview
the Witch Head Nebula is a reflection nebula in the constellation Eridanus. It spans about 180 arcminutes of sky.
Location in the sky
Precision measurements
Distances and velocities from SIMBAD · NGC 1909
| Distance | 962.161321 ly | SIMBAD · catalogued |
| Physical size (major axis) | 50.378649 ly | SIMBAD · derived |
| Physical size (minor axis) | 16.792883 ly | SIMBAD · derived |
| Right ascension (ICRS) | 75.5 deg | SIMBAD · measured |
| Declination (ICRS) | -7.9 deg | SIMBAD · measured |
Full field-level provenance
- Distance: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · mesDistance · dist · 2020A&A...633A..51Z · distance indicator: plx · catalogued value · source value 295 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
- 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 · direct catalogue measurement · retrieved 2026-07-11
- Declination (ICRS): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · dec · 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 Eridanus
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.