Sombrero Galaxy (Messier 104 / NGC 4594)
Coordinates, TRGB distance (9.55 Mpc / 31.1 Mly), edge-on dust lane, 1-billion-M☉ central black hole, and observing guide for M104.
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) | 8 mag | ± 0.1 mag | Integrated CCD aperture photometry | definitive | Revised New General Catalogue and Index Catalogue (RNGC/IC) |
| Extragalactic distance | 9550000 pc | ± 310000 pc | HST Tip of the Red Giant Branch (TRGB, McQuinn et al. 2016: 9.55 ± 0.31 Mpc / 31.1 Mly) | definitive | SIMBAD Astronomical Database (CDS) |
| Apparent major axis | 8.7 arcmin | ± 0.3 arcmin | Optical isophotal dimensions (8.7′ × 3.5′) | definitive | Revised New General Catalogue and Index Catalogue (RNGC/IC) |
| Heliocentric recession velocity | 1091 km/s | ± 5 km/s | Slipher 1912 / modern optical absorption spectroscopy | definitive | SIMBAD Astronomical Database (CDS) |
J2000 Equatorial Sky Chart & Culmination Altitude
The chart below plots Sombrero Galaxy (Messier 104 / NGC 4594) at RA 12h 39m 59.43s, Dec -11° 37′ 23.0″ within Virgo, 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
The Sombrero Galaxy (Messier 104, NGC 4594) is a striking SA(s)a galaxy situated 9.55 ± 0.31 megaparsecs (31.1 million light-years) away on the southern border of Virgo and Corvus. Discovered by Pierre Méchain in May 1781 and handwritten by Charles Messier into his personal copy of the catalog (officially added as M104 by Camille Flammarion in 1921), M104 was the galaxy used by Vesto Slipher at Lowell Observatory in 1912–1914 to measure a +1,090 km/s Doppler redshift and rotational tilt—providing the first spectroscopic evidence of receding extragalactic systems.
Tilted just 6 degrees from edge-on, the Sombrero combines two distinct structural components: an enormous, nearly spherical stellar halo and bulge populated by ~2,000 globular clusters (resembling an elliptical galaxy), bisected by a razor-sharp, symmetric ring of cold molecular gas and dark interstellar dust.
In 2024 the James Webb Space Telescope's Mid-Infrared Instrument (MIRI) imaged M104 at 7.7 to 21 microns, causing the smooth optical stellar halo to vanish and revealing that the outer dust lane is actually a clumpy, bullseye-like ring surrounding a 1-billion-solar-mass low-luminosity active black hole.
Practical Visual Observing Guide
- Situated 11.5° west of Spica (α Virginis) and 5.5° northeast of Algorab (δ Corvi); star-hop through the telescopic asterisms nicknamed the 'Stargate' (STT 256) and 'Jaws' right to M104.
- Because M104 has a high surface brightness (magnitude 8.0 packed into 8.7 × 3.5 arcminutes), its glowing spindle is visible in 10×50 binoculars and any 60 mm refractor.
- In a 150–200 mm telescope at 120×–180×, the dark equatorial dust lane slicing just south of the blazing nucleus is unmistakable.
Catalog Cross-Identifications & Aliases
Common Aliases: M104 · NGC 4594
| Catalog Authority | Identifier |
|---|---|
| MESSIER | M 104 |
| NGC | NGC 4594 |
| SIMBAD | M 104 |
| WIKIDATA | Q14359 |
Related Objects, Comparisons & Guides
Messier 87 (Virgo A Giant Elliptical Galaxy)
Coordinates, distance (16.4 Mpc / 53.5 Mly), EHT 6.5-billion M☉ black hole M87*, relativistic jet, and observing guide for Messier 87.
Spica (Alpha Virginis Ellipsoidal Binary)
Coordinates, Hipparcos distance (250 ly), 4.01-day close B-star binary, precession discovery history, and observing guide for Spica.
Bode's Galaxy (Messier 81 / NGC 3031)
Coordinates, Cepheid/TRGB distance (3.63 Mpc / 11.8 Mly), magnitude 6.94, M81–M82 tidal pair, and observing guide for Bode's Galaxy in Ursa Major.
Andromeda Galaxy (Messier 31 / NGC 224)
Coordinates, Cepheid/TRGB distance (765 kpc / 2.50 Mly), magnitude 3.44, blueshift (−300 km/s), and observing guide for Andromeda (M31).
Spring Galaxy Season: Ursa Major to Virgo
Spring galaxy observing guide from Ursa Major (M81, M82, Whirlpool M51) across Coma/Virgo to giant elliptical M87, the Sombrero Galaxy (M104), and 3C 273.
Small-Telescope Messier Objects Tour (80–150mm)
Curated seasonal tour of flagship Messier clusters, nebulae, and galaxies optimized for 80 mm to 150 mm (3-inch to 6-inch) refractors and reflectors.
Surface Brightness & Extended Objects Guide
Why surface brightness (mag/arcsec²) governs nebula and galaxy visibility more than integrated magnitude, and how exit pupil controls eyepiece contrast.
Proper Motion, Radial Velocity & Redshift
How astronomers combine tangential proper motion (mas/yr), Doppler radial velocity (km/s), and cosmological redshift (z) to reconstruct 3D space motion.
Messier Catalog (M) Objects & Cross-Reference
Guide and cross-walk to Charles Messier's flagship deep-sky catalog (M1 to M104 in FastAstro), linking Messier numbers to NGC IDs, distances, and magnitudes.
NGC & Caldwell Deep-Sky Cross-Walk Catalog
Cross-reference guide to Dreyer's New General Catalogue (NGC) showpieces, including southern gems Omega Centauri, 47 Tucanae, Carina Nebula, and the Veil.
Scientific Sources & Dataset Provenance
- Revised New General Catalogue and Index Catalogue (RNGC/IC) (2024/2026 edition): Steinicke, W. 2010, Observing and Cataloguing Nebulae and Star Clusters (Cambridge Univ. Press); Verga, M. OpenNGC (CC-BY-SA 4.0 / data tables) — Wolfgang Steinicke / OpenNGC
- JWST / MAST Science Archive & Mission Documentation (Cycle 1–4 Public Releases (2022–2026)): Rigby, J., et al. 2023, PASP, 135, 048001 (The Science Performance of JWST as Characterized in Commissioning) — NASA / ESA / CSA / STScI
- 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