M 3
Scientific overview
M 3 is a globular cluster in the constellation Canes Venatici. It shines at apparent magnitude 6.39 and spans about 16.2 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 · M 3
| Distance | 32,616 ly | SIMBAD · catalogued |
| Physical size (major axis) | 153.697573 ly | SIMBAD · derived |
| Radial velocity | -147.2 ± 0.2 km/s | SIMBAD · measured |
| Right ascension (ICRS) | 205.548417 deg | SIMBAD · measured |
| Declination (ICRS) | 28.377278 deg | SIMBAD · measured |
Full field-level provenance
- Distance: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · mesDistance · dist · 2008MNRAS.389.1924F · catalogued value · source value 0.01 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
- Radial velocity: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · rvz_radvel · 2018MNRAS.478.1520B · direct catalogue measurement · retrieved 2026-07-11
- Right ascension (ICRS): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · ra · 2010AJ....140.1830G · direct catalogue measurement · retrieved 2026-07-11
- Declination (ICRS): Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · basic · dec · 2010AJ....140.1830G · 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 Canes Venatici
| Object | Type | Mag | Size (′) |
|---|---|---|---|
| M 94M 94 · NGC 4736 | Barred spiral galaxy | 8.24 | 7.74 |
| Whirlpool GalaxyM 51 · NGC 5194 | Barred spiral galaxy | 8.36 | 13.71 |
| Sunflower GalaxyM 63 · NGC 5055 | Spiral galaxy | 8.61 | 11.83 |
| Whale GalaxyC 32 · NGC 4631 | Barred spiral galaxy | 9.24 | 14.45 |
| M 106M 106 · NGC 4258 | Spiral galaxy | 9.29 | 16.98 |
| NGC 5195NGC 5195 | Barred spiral galaxy | 9.58 | 5.5 |
| NGC 4449C 21 · NGC 4449 | Irregular galaxy | 9.64 | 4.66 |
| NGC 4490NGC 4490 | Barred spiral galaxy | 9.72 | 6.71 |
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.