Messier 5 (NGC 5904)
Coordinates, Gaia DR3 distance (7.48 kpc), magnitude 5.65, eccentric halo orbit, and observing guide for Messier 5 (NGC 5904) in Serpens Caput.
Provenance-Backed Scientific Measurements
Every measurement below preserves its unit, uncertainty interval, observational method, reference epoch, quality status, and primary catalog source. See Uncertainty & Provenance for how competing measurements are handled.
| Parameter | Value | Uncertainty | Method & Epoch | Quality Status | Source Archive |
|---|---|---|---|---|---|
| Integrated visual magnitude (V) | 5.65 mag | ± 0.04 mag | Integrated photoelectric & CCD photometry | definitive | Catalog of Parameters for Milky Way Globular Clusters |
| Heliocentric distance | 24400 ly | ± 300 ly | Gaia EDR3 parallax + dynamical velocity dispersion (7.48 ± 0.09 kpc) (J2016.0) | definitive | ESA Gaia Archive — Data Release 3 |
| Apparent tidal diameter | 23 arcmin | ± 1.5 arcmin | Outer surface-brightness profile fitting | high-confidence | Revised New General Catalogue and Index Catalogue (RNGC/IC) |
| Main-sequence turnoff age | 11.5 Gyr | ± 0.4 Gyr | HST ACS color-magnitude turnoff fitting | model-dependent | Catalog of Parameters for Milky Way Globular Clusters |
J2000 Equatorial Sky Chart & Culmination Altitude
The chart below plots Messier 5 (NGC 5904 Globular Cluster) at RA 15h 18m 33.22s, Dec +02° 04′ 51.7″ within Serpens (Caput), alongside peak meridian transit altitudes for 40°N and 30°S observers. Use the RA/Dec Coordinate Converter to compute exact culmination altitude for your latitude.
Astrophysical Context & Structure
Messier 5 (NGC 5904) is widely regarded by visual observers as the finest globular cluster in the northern hemisphere, rivaling or surpassing M13 in Hercules in both integrated brightness (magnitude 5.65) and outer halo richness. Discovered by German astronomer Gottfried Kirch and his wife Maria Margarethe on May 5, 1702, while observing a comet, and independently cataloged by Charles Messier in May 1764, M5 lies 24,400 light-years (7.48 ± 0.09 kiloparsecs) away in the western head of Serpens.
Spanning roughly 165 light-years in physical diameter with a dynamical mass of ~370,000 solar masses, M5 travels along a highly eccentric, plunging Galactic orbit that carries it from within 9,000 light-years of the Galactic center out to an apogalacticon beyond 110,000 light-years. Deep wide-field imaging with Gaia DR3 has detected a 50-degree-long trailing tidal stream of stars stripped from M5 during previous passages through the Milky Way's gravitational potential.
M5 is also a premier laboratory for variable and exotic stars, containing over 105 RR Lyrae variables, two bright W Virginis Type II Cepheids (V42 with a 25.7-day period and V84 with a 26.4-day period), and the dwarf nova cataclysmic variable V101. Its flattened outer isophotes reflect both internal rotation and tidal torque from the Milky Way disk.
Practical Visual Observing Guide
- Positioned just 22 arcminutes north-northwest of the 5.1-magnitude double star 5 Serpentis, about 8° southwest of Unukalhai (α Serpentis).
- Under dark skies (Bortle 1–3) M5 is a borderline naked-eye object and stands out in 7×50 binoculars as a bright, non-stellar pearl paired closely with 5 Serpentis.
- In a 100–200 mm telescope at 120×–200×, M5 explodes into curved, spider-like legs of 12.2-magnitude red and blue horizontal-branch stars radiating outward from a compressed, slightly oval Class V core.
Catalog Cross-Identifications & Aliases
Common Aliases: M5 · NGC 5904 · Rose Cluster
| Catalog Authority | Identifier |
|---|---|
| MESSIER | M 5 |
| NGC | NGC 5904 |
| SIMBAD | M 5 |
| WIKIDATA | Q11203 |
Related Objects, Comparisons & Guides
Messier 13 (Hercules Globular Cluster)
Coordinates, Gaia DR3 distance (7.42 kpc), visual magnitude 5.78, and Keystone finder guide for Messier 13 (NGC 6205) in Hercules.
Messier 3 (NGC 5272 Globular Cluster)
Coordinates, Gaia DR3 distance (10.18 kpc), magnitude 6.19, RR Lyrae variable benchmark data, and observing guide for Messier 3 in Canes Venatici.
Messier 10 (NGC 6254 Globular Cluster)
Coordinates, Gaia DR3 distance (5.07 kpc), magnitude 6.4, blue-straggler core data, and observing guide for Messier 10 (NGC 6254) in Ophiuchus.
Apparent vs Absolute Magnitude Explained
Understand the logarithmic Pogson astronomical magnitude scale, apparent visual magnitude (m), absolute magnitude (M at 10 parsecs), and bolometric corrections.
Trigonometric Parallax, Parsecs & Gaia DR3
How trigonometric parallax (d_pc = 1 / p_arcsec), the distance modulus equation, Hipparcos, and Gaia DR3 microarcsecond astrometry measure cosmic distances.
Scientific Sources & Dataset Provenance
- Catalog of Parameters for Milky Way Globular Clusters (2010 / 2021 Gaia EDR3 revision): Harris, W. E. 1996 (2010 ed.), AJ, 112, 1487; Vasiliev, E. & Baumgardt, H. 2021, MNRAS, 505, 5978 — McMaster University / Gaia EDR3 Cluster Survey
- ESA Gaia Archive — Data Release 3 (DR3 (2022-06-13)): Gaia Collaboration, Vallenari, A., et al. 2023, A&A, 674, A1 (Gaia Data Release 3) — European Space Agency / Gaia DPAC
- SIMBAD Astronomical Database (CDS) (2026-10 release): Wenger, M., et al. 2000, A&AS, 143, 9 (The SIMBAD astronomical database) — Centre de Données astronomiques de Strasbourg