Galaxies · Constellation Virgo

Messier 90 (NGC 4569 / Arp 76)

J2000 coordinates, distance (53.8 Mly), magnitude 9.52, −235 km/s blueshift, truncated H II disk, IC 3583 companion, and observing guide for Messier 90.

Right Ascension (J2000.0)12h 36m 49.80s
Declination (J2000.0)+13° 09′ 46.3″
Primary ClassificationGiant ram-pressure-stripped SAB(rs)ab spiral galaxy (blueshifted Virgo member)
Best Observing SeasonSpring (March–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 90 (NGC 4569 / Arp 76)
ParameterValueUncertaintyMethod & EpochQuality StatusSource Archive
Integrated visual magnitude (V)9.52 mag± 0.09 magIntegrated CCD aperture photometrydefinitiveRevised New General Catalogue and Index Catalogue (RNGC/IC)
Distance in light-years53800000 ly± 3900000 lyTip of the Red Giant Branch (TRGB) & Tully-Fisher relation (16.5 ± 1.2 Mpc)high-confidenceSIMBAD Astronomical Database (CDS)
Apparent major axis9.5 arcmin± 0.4 arcminOptical 25 mag/arcsec² isophotal dimensions (9.5′ × 4.4′)definitiveRevised New General Catalogue and Index Catalogue (RNGC/IC)
Heliocentric radial velocity-235 km/s± 4 km/sH I 21-cm and optical emission spectroscopy (blueshifted Virgo spiral)definitiveSIMBAD Astronomical Database (CDS)
Measurement Uncertainties & Competing Solutions: Because M90's orbital plunge through the Virgo Cluster gives it a heliocentric blueshift of −235 km/s, redshift-independent TRGB and infrared Tully-Fisher measurements are required, placing M90 at 16.5 ± 1.2 Mpc (53.8 ± 3.9 Mly).

J2000 Equatorial Sky Chart & Culmination Altitude

The chart below plots Messier 90 (NGC 4569 Ram-Stripped Spiral) at RA 12h 36m 49.80s, Dec +13° 09′ 46.3″ 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.

J2000 Equatorial Sky Position (Virgo) +90° 0° −90° 24h 12h RA 0h Peak Meridian Altitude 63° 40°N Lat 47° 30°S Lat RA: 12h 36m 49.80s Dec: +13° 09′ 46.3″ Epoch: J2000.0 · V = 9.52 mag First-party vector diagram derived from IAU / CDS SIMBAD / Gaia DR3 astrometry.

Astrophysical Context & Structure

Discovered by Charles Messier on March 18, 1781, Messier 90 (NGC 4569) is physically one of the largest spiral galaxies in the Virgo Cluster, with an optical disk spanning nearly 150,000 light-years at a distance of 53.8 million light-years. Like elliptical M86, M90 exhibits a striking heliocentric blueshift of −235 km/s—meaning it has already swung through the gravitational core of the Virgo Cluster and is hurtling toward us on the near side of the cluster at roughly 1,300 km/s relative to the cluster center.

That high-speed passage through the dense Virgo intracluster medium has transformed M90 into the most dramatic textbook case of ram-pressure stripping in a giant spiral galaxy. More than 90% of M90's cold neutral hydrogen gas has been swept out of its outer disk—truncating active H II star formation to the inner one-third of its stellar disk—while deep narrowband H-alpha imaging with the Canada-France-Hawaii Telescope (MegaCam) revealed spectacular 260,000-light-year-long ionized gas tails streaming behind the galaxy.

While the outer arms of M90 are fading into a smooth, passive lenticular state, gas funneled into its central 1,000 light-years fuels a fierce nuclear starburst of ~50,000 O- and B-type stars that drives a bipolar superbubble of ionized gas above the core. Halton Arp cataloged M90 together with its 13.3-magnitude irregular satellite IC 3583 (located 6′ north-northwest) as Arp 76.

Practical Visual Observing Guide

Minimum Instrument80–100 mm telescope
Recommended Magnification80×–160×
Best Evening SeasonSpring (March–June)
  • Located 1.7° east-northeast of M87 and 1.2° north of M58 in the heart of the Virgo Cluster.
  • In 100–150 mm telescopes at 60×–100×, M90 shows an unusually bright, star-like nuclear starburst core set inside a smooth, elongated 9′ × 4′ oval halo oriented NNE–SSW (PA 20°).
  • Under dark skies with a 250–300 mm telescope at 140×–180×, trace the brighter inner spiral lens and look 6′ NNW for the faint smudge of companion IC 3583.

Catalog Cross-Identifications & Aliases

Common Aliases: M90 · NGC 4569 · UGC 7786 · Arp 76

Cross-Catalog Identifiers for Messier 90 (NGC 4569 / Arp 76)
Catalog AuthorityIdentifier
MESSIERM 90
NGCNGC 4569
SIMBADM 90
WIKIDATAQ14051
Related Object · Virgo

Messier 86 (NGC 4406 Blueshifted Lenticular)

J2000 coordinates, SBF distance (55.4 Mly), magnitude 8.90, −244 km/s blueshift, ram-pressure X-ray plume, and observing guide for Messier 86 in Virgo.

Related Object · Coma Berenices

Messier 88 (NGC 4501 Symmetrical Spiral)

J2000 coordinates, Tully-Fisher distance (54.1 Mly), magnitude 9.60, multi-arm SA(rs)b spiral, ICM compression edge, and observing guide for Messier 88.

Reference Guide

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.

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
  • 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