Galaxies · Constellation Ursa Major

Vacuum Cleaner Galaxy (Messier 109 / NGC 3992)

J2000 coordinates, Tully-Fisher distance (67.2 Mly), magnitude 9.80, grand SB(rs)bc barred spiral, Phecda glare tips, and observing guide for M109.

Right Ascension (J2000.0)11h 57m 35.98s
Declination (J2000.0)+53° 22′ 28.3″
Primary ClassificationGrand-design SB(rs)bc barred spiral galaxy (dominant Ursa Major Cloud member)
Best Observing SeasonLate Winter to Spring (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 Vacuum Cleaner Galaxy (Messier 109 / NGC 3992)
ParameterValueUncertaintyMethod & EpochQuality StatusSource Archive
Integrated visual magnitude (V)9.8 mag± 0.1 magIntegrated CCD aperture photometrydefinitiveRevised New General Catalogue and Index Catalogue (RNGC/IC)
Distance in light-years67200000 ly± 4900000 lyBaryonic Tully-Fisher relation & Type Ia SN 1956A standardization (20.6 ± 1.5 Mpc)high-confidenceSIMBAD Astronomical Database (CDS)
Apparent major axis7.6 arcmin± 0.3 arcminOptical isophotal dimensions (7.6′ × 4.7′)definitiveRevised New General Catalogue and Index Catalogue (RNGC/IC)
Heliocentric recession velocity1048 km/s± 2 km/sWSRT H I 21-cm synthesis rotation curvedefinitiveSIMBAD Astronomical Database (CDS)
Measurement Uncertainties & Competing Solutions: Baryonic Tully-Fisher relations and Type Ia supernova (SN 1956A) light-curve standardization yield 20.6 ± 1.5 Mpc (67.2 ± 4.9 Mly), with ~7% uncertainty from cosmic flow velocities across the Ursa Major Filament.

J2000 Equatorial Sky Chart & Culmination Altitude

The chart below plots Vacuum Cleaner Galaxy (M109 / NGC 3992) at RA 11h 57m 35.98s, Dec +53° 22′ 28.3″ within Ursa Major, 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 (Ursa Major) +90° 0° −90° 24h 12h RA 0h Peak Meridian Altitude 77° 40°N Lat 7° 30°S Lat RA: 11h 57m 35.98s Dec: +53° 22′ 28.3″ Epoch: J2000.0 · V = 9.8 mag First-party vector diagram derived from IAU / CDS SIMBAD / Gaia DR3 astrometry.

Astrophysical Context & Structure

Observed by Pierre Méchain on March 12, 1781, and officially added to the Messier catalog by Owen Gingerich in 1953, Messier 109 (NGC 3992, sometimes nicknamed the Vacuum Cleaner Galaxy for its prominent central bar and curved suction-hose arms) is the most distant object in the Ursa Major Cloud and one of the most distant galaxies in the Messier catalog at ~67.2 million light-years. Spanning roughly 145,000 light-years across its SB(rs)bc disk, M109 is physically larger than the Andromeda Galaxy and serves as the gravitational anchor of the M109 Group of more than 50 galaxies.

Westerbork Synthesis Radio Telescope 21-centimeter H I maps show a classic dynamical signature of a strong galactic bar: the inner stellar bar has swept out a conspicuous central hole in the cold neutral hydrogen gas, piling atomic gas into the surrounding inner ring and spiral arms while low-level gas inflows feed a LINER active nucleus.

Three faint dwarf companion galaxies—UGC 6923, UGC 6940, and UGC 6969—orbit in the immediate vicinity of M109 and show synchronized H I velocity fields with the main galaxy. In March 1956 a white dwarf in M109's eastern spiral arm exploded as the bright Type Ia supernova SN 1956A, peaking at photographic magnitude 12.3.

Practical Visual Observing Guide

Minimum Instrument80–100 mm telescope (200 mm+ to resolve central bar)
Recommended Magnification100×–160× (keep 2.4-mag Phecda outside the eyepiece field)
Best Evening SeasonLate Winter to Spring (February–June)
  • One of the easiest galaxies in the entire sky to point to: sit just 40 arcminutes (two-thirds of a degree) southeast of the brilliant 2.4-magnitude star Phecda (γ Ursae Majoris) at the bottom-left corner of the Big Dipper's bowl!
  • Because Phecda's dazzling glare floods wide-field eyepieces, use 100×–150× magnification to push Phecda just outside the field of view so M109's 7.6′ × 4.7′ halo stands out against a dark background.
  • In a 250–350 mm telescope under dark skies, you can clearly trace the bright central bar (oriented NE–SW) and the oval inner ring.

Catalog Cross-Identifications & Aliases

Common Aliases: M109 · NGC 3992 · UGC 6937 · Vacuum Cleaner Galaxy

Cross-Catalog Identifiers for Vacuum Cleaner Galaxy (Messier 109 / NGC 3992)
Catalog AuthorityIdentifier
MESSIERM 109
NGCNGC 3992
SIMBADM 109
WIKIDATAQ14365
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Surfboard Galaxy (Messier 108 / NGC 3556)

J2000 coordinates, Tully-Fisher distance (45.9 Mly), magnitude 10.00, mottled edge-on disk, H I supershells, and observing guide for Messier 108.

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J2000 coordinates, Cepheid/TRGB distance (21.6 Mly), magnitude 7.86, giant H II regions, SN 2011fe & SN 2023ixf, and observing guide for M101.

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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.

Reference Guide

Bortle Dark-Sky Scale & Sky Brightness Guide

Reference guide to the 9-class Bortle Dark-Sky Scale, zenith Sky Quality Meter (SQM) readings in mag/arcsec², naked-eye limiting magnitude, and light pollution.

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