47 Tuc Cluster
Scientific overview
47 Tuc Cluster is a globular cluster in the constellation Tucana. It shines at apparent magnitude 4.09 and spans about 31.8 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 104
| Distance | 13,535 ly | SIMBAD · catalogued |
| Physical size (major axis) | 125.206597 ly | SIMBAD · derived |
| Radial velocity | -17.2 ± 0.1 km/s | SIMBAD · measured |
| Right ascension (ICRS) | 6.022329 deg | SIMBAD · measured |
| Declination (ICRS) | -72.081444 deg | SIMBAD · measured |
Full field-level provenance
- Distance: Centre de données astronomiques de Strasbourg (CDS) · SIMBAD · mesDistance · dist · 2015ApJ...812..149W · distance indicator: PM · catalogued value · source value 4.15 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
- 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 · 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). 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 Tucana
| Object | Type | Mag | Size (′) |
|---|---|---|---|
| Small Magellanic CloudNGC 292 | Barred spiral galaxy | 2.3 | 299.92 |
| NGC 362C 104 · NGC 362 | Globular cluster | 6.58 | 8.7 |
| NGC 330NGC 330 | Open cluster | 9.55 | 2.8 |
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.