NGC 3621
Scientific overview
NGC 3621 is a barred spiral galaxy in the constellation Hydra. It shines at apparent magnitude 9.55 and spans about 9.79 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 and redshift from NED · NGC 3621
| Distance | 1.6895e+7 ly | SIMBAD · catalogued |
| Physical size (major axis) | 48,113 ly | SIMBAD · derived |
| Physical size (minor axis) | 19,806 ly | SIMBAD · derived |
| Redshift (z) | 0.002403 ± 1.3343e-6 | NED · catalogued |
| Radial velocity | 729.8 km/s | SIMBAD · measured |
| Right ascension (ICRS) | 169.567917 deg | SIMBAD · measured |
| Declination (ICRS) | -32.8126 deg | SIMBAD · measured |
Full field-level provenance
- Distance: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · mesDistance · dist · 2022MNRAS.511.6160K · distance indicator: T-F · catalogued value · source value 5.18 Mpc · 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
- Redshift (z): NASA/IPAC Extragalactic Database · NED · ObjectLookup · Redshift · 2018MNRAS.480.1973K · catalogued value · NED quality SUN · retrieved 2026-07-11
- Radial velocity: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · rvz_radvel · 2004MNRAS.350.1195M · direct catalogue measurement · retrieved 2026-07-11
- Right ascension (ICRS): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · ra · 2006AJ....131.1163S · direct catalogue measurement · retrieved 2026-07-11
- Declination (ICRS): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · dec · 2006AJ....131.1163S · 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). Redshift is the object's measured redshift — a negative value is a blueshift (the galaxy is approaching, its motion dominated by local rather than cosmic expansion). Fields a source did not provide are omitted, never invented.
Other objects in Hydra
| Object | Type | Mag | Size (′) |
|---|---|---|---|
| M 48M 48 · NGC 2548 | Open cluster | 5.8 | 28.2 |
| Southern Pinwheel GalaxyM 83 · NGC 5236 | Spiral galaxy | 7.21 | 13.61 |
| Jupiter's Ghost NebulaC 59 · NGC 3242 | Planetary nebula | 7.7 | 0.42 |
| M 68M 68 · NGC 4590 | Globular cluster | 7.96 | 6.6 |
| NGC 3923NGC 3923 | Elliptical galaxy | 9.6 | 6.89 |
| NGC 3585NGC 3585 | Elliptical galaxy | 9.69 | 6.61 |
| NGC 5694C 66 · NGC 5694 | Globular cluster | 10.89 | 3.3 |
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.