Galaxies · Constellation Leo

Messier 95 (NGC 3351)

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.

Right Ascension (J2000.0)10h 43m 57.70s
Declination (J2000.0)+11° 42′ 13.3″
Primary ClassificationArchetypal SB(r)b theta-shaped barred spiral galaxy (M96 / Leo I Group)
Best Observing SeasonSpring (February–June)

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.

Astrometric, Photometric, and Physical Parameters for Messier 95 (NGC 3351)
ParameterValueUncertaintyMethod & EpochQuality StatusSource Archive
Integrated visual magnitude (V)9.73 mag± 0.08 magIntegrated CCD aperture photometrydefinitiveRevised New General Catalogue and Index Catalogue (RNGC/IC)
Distance in light-years32600000 ly± 1100000 lyHST Key Project Classical Cepheids + TRGB (10.00 ± 0.33 Mpc)definitiveSH0ES Local Distance Ladder Hubble Constant
Apparent major axis7.4 arcmin± 0.3 arcminOptical isophotal dimensions (7.4′ × 5.0′)definitiveRevised New General Catalogue and Index Catalogue (RNGC/IC)
Heliocentric recession velocity778 km/s± 2 km/sH I 21-cm synthesis rotation velocitydefinitiveSIMBAD Astronomical Database (CDS)
Measurement Uncertainties & Competing Solutions: M95 served as a primary Hubble Space Telescope Key Project calibrator, where 49 Classical Cepheid variables combined with TRGB star counts fix its distance at 10.00 ± 0.33 Mpc (32.6 ± 1.1 Mly).

J2000 Equatorial Sky Chart & Culmination Altitude

The chart below plots Messier 95 (NGC 3351 Theta-Shaped Spiral) at RA 10h 43m 57.70s, Dec +11° 42′ 13.3″ 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.

J2000 Equatorial Sky Position (Leo) +90° 0° −90° 24h 12h RA 0h Peak Meridian Altitude 62° 40°N Lat 48° 30°S Lat RA: 10h 43m 57.70s Dec: +11° 42′ 13.3″ Epoch: J2000.0 · V = 9.73 mag First-party vector diagram derived from IAU / CDS SIMBAD / Gaia DR3 astrometry.

Astrophysical Context & Structure

Discovered by Pierre Méchain on March 20, 1781, alongside neighboring M96, Messier 95 (NGC 3351) is a prominent member of the Leo I (M96) Galaxy Group located 32.6 million light-years away under the belly of Leo. Spanning ~70,000 light-years across, M95 is one of the cleanest textbook examples in the sky of a theta-shaped (θ) SB(r)b barred spiral galaxy: a prominent golden stellar bar slices directly across a nearly circular inner star-forming ring, from which two tightly wound outer spiral arms emerge.

At the very center of M95, gravitational torques from the main stellar bar funnel cold molecular gas inward to an inner Lindblad resonance, igniting a dazzling 2,000-light-year-wide circumnuclear starburst ring resolved in breathtaking detail by both the Hubble Space Telescope and the James Webb Space Telescope (PHANGS-JWST survey).

In March 2012 a red supergiant star of ~8 solar masses in M95's outer ring exploded as the bright Type II-P supernova SN 2012aw, reaching magnitude 13.3 and allowing astronomers to directly identify the pre-explosion supergiant progenitor star in archival Hubble images.

Practical Visual Observing Guide

Minimum Instrument80–100 mm telescope (200 mm+ to resolve the central bar and θ-ring)
Recommended Magnification80×–160×
Best Evening SeasonSpring (February–June)
  • Located 42 arcminutes west of M96, roughly one-third of the way along a line from Regulus (α Leonis) to Chertan (θ Leonis).
  • A wide-field eyepiece (35×–50×) can fit M95 and M96 in the same field of view, with the M105/NGC 3384 pair just 50′ northeast of M96.
  • In a 200–300 mm telescope at 110×–160× under dark skies, M95's bright core is crossed by a distinct bar (oriented NW–SE at PA 44°) enclosed within a ghostly circular ring looking like the Greek letter theta (θ).

Catalog Cross-Identifications & Aliases

Common Aliases: M95 · NGC 3351 · UGC 5850 · PGC 32007

Cross-Catalog Identifiers for Messier 95 (NGC 3351)
Catalog AuthorityIdentifier
MESSIERM 95
NGCNGC 3351
SIMBADM 95
WIKIDATAQ14061
Related Object · Leo

Messier 96 (NGC 3368 Leo I Group Anchor)

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.

Related Object · Leo

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.

Related Object · Leo

Messier 65 (NGC 3623 Leo Triplet Spiral)

J2000 coordinates, distance (34.6 Mly), magnitude 9.31, tightly wound SA(rs)a arms, prominent eastern dust lane, and observing guide for Messier 65.

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