Messier 96 (NGC 3368)
J2000 coordinates, HST Cepheid distance (34.9 Mly), magnitude 9.25, asymmetric dusty spiral arms, double bar, and observing guide for Messier 96 in Leo.
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) | 9.25 mag | ± 0.08 mag | Integrated CCD aperture photometry | definitive | Revised New General Catalogue and Index Catalogue (RNGC/IC) |
| Distance in light-years | 34900000 ly | ± 1200000 ly | HST Cepheid period-luminosity relation + SN 1998bu Type Ia calibration (10.7 ± 0.37 Mpc) | definitive | SH0ES Local Distance Ladder Hubble Constant |
| Apparent major axis | 7.6 arcmin | ± 0.3 arcmin | Optical isophotal dimensions including outer tidal loop (7.6′ × 5.2′) | definitive | Revised New General Catalogue and Index Catalogue (RNGC/IC) |
| Heliocentric recession velocity | 897 km/s | ± 3 km/s | H I 21-cm synthesis rotation velocity | definitive | SIMBAD Astronomical Database (CDS) |
J2000 Equatorial Sky Chart & Culmination Altitude
The chart below plots Messier 96 (NGC 3368 Leo I Group Anchor) at RA 10h 46m 45.74s, Dec +11° 49′ 11.8″ within Leo, 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
Discovered by Pierre Méchain on March 20, 1781, Messier 96 (NGC 3368) is the brightest and most massive spiral galaxy in the Leo I (M96) Group, shining at visual magnitude 9.25 from a distance of 34.9 million light-years. While its bright inner disk spans ~66,000 light-years across, deep exposures reveal a lopsided, low-surface-brightness outer ring of stars and dust filaments stretching more than 100,000 light-years across—with the galaxy's luminous core noticeably offset from the geometric center of its outer disk.
That striking asymmetry is the signature of gravitational interactions within the Leo I Group: M96 is linked by a giant intergalactic ring of cold neutral hydrogen (the 'Leo Ring', spanning over 650,000 light-years) to the neighboring M105 / NGC 3384 pair just 50 arcminutes to its north-northeast, likely forged by a past head-on galaxy collision roughly 1.2 billion years ago.
Near-infrared imaging shows that M96 possesses a nested 'bar-within-a-bar' nuclear structure channeling gas toward a ~7.5-million-solar-mass central black hole. In May 1998 M96 hosted the famous Type Ia supernova SN 1998bu, which peaked at magnitude 11.8 and produced a long-lasting dust-scattered light echo resolved by the Hubble Space Telescope.
Practical Visual Observing Guide
- Sits in the center of the Leo I Galaxy Group, 42′ east of M95 and 50′ south-southwest of the M105 / NGC 3384 / NGC 3389 trio.
- At magnitude 9.25 with a compact, bright inner disk (3′ × 2′), M96 is the easiest member of the M95/M96/M105 group to spot in 70–100 mm telescopes.
- In a 200–250 mm telescope at 120×–160×, M96 shows a bright, slightly oval core surrounded by an asymmetric, mottled halo; look 5′ north-northwest of the core for the faint background spiral galaxy 2MFGC 8391 seen right through M96's outer arm in deep images.
Catalog Cross-Identifications & Aliases
Common Aliases: M96 · NGC 3368 · UGC 5882 · PGC 32192
| Catalog Authority | Identifier |
|---|---|
| MESSIER | M 96 |
| NGC | NGC 3368 |
| SIMBAD | M 96 |
| WIKIDATA | Q14065 |
Related Objects, Comparisons & Guides
Messier 95 (NGC 3351 Theta-Shaped Spiral)
J2000 coordinates, HST Cepheid distance (32.6 Mly), magnitude 9.73, textbook SB(r)b bar and ring, circumnuclear knots, and observing guide for Messier 95.
Messier 105 (NGC 3379 Leo I Elliptical)
J2000 coordinates, SBF/TRGB distance (34.2 Mly), magnitude 9.28, E1 standard luminosity profile, Leo I trio, and observing guide for Messier 105.
Messier 66 (NGC 3627 Asymmetric Spiral)
J2000 coordinates, Cepheid/TRGB distance (31.3 Mly), magnitude 8.92, tidally warped arms, five supernovae, and observing guide for Messier 66 in Leo.
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.
Angular Size, Separation & Field of View
How angular diameter (degrees, arcminutes, arcseconds), spherical angular separation, and small-angle physical diameter relate to telescope field of view.
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
- SH0ES Local Distance Ladder Hubble Constant (2022 Baseline Cepheid + SN Ia): Riess, A. G., et al. 2022, ApJL, 934, L7 (A Comprehensive Measurement of the Local Value of the Hubble Constant) — SH0ES Collaboration (HST / JWST)
- 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