Messier 66

Messier 66

Messier 66
M66 as observed with the Spitzer Space Telescope as part of the SINGS. The image is a four-channel false-color composite, where blue indicates emission at 3.6 micrometers, green corresponds to 4.5 micrometers, and red to 5.8 and 8.0 micrometers. The contribution from starlight (measured at 3.6 micrometers) in this picture has been subtracted from the 5.8 and 8 micrometer images to enhance the visibility of the polycyclic aromatic hydrocarbon emissions.
Observation data (J2000 epoch)
Constellation Leo
Right ascension 11h 20m 15.0s[1]
Declination +12° 59′ 30″[1]
Redshift 0.002425 (727 ± 3 km/s)[1]
Distance 36 ± 5.0 Mly (11.0 ± 1.5 Mpc)
Type SAB(s)b[1]
Apparent dimensions (V) 9.1′ × 4.2′[1]
Apparent magnitude (V) 8.9[2]
Notable features Galaxy in the Leo Triplet
Other designations
NGC 3627, UGC 6346, PGC 34695, Arp 16[1]

Messier 66 (also known as NGC 3627) is an intermediate spiral galaxy about 36 million light-years away in the constellation Leo. It was discovered by Charles Messier in 1780. M66 is about 95 thousand light-years across[3] with striking dust lanes and bright star clusters along sweeping spiral arms.[4] M66 is part of the famous Leo Triplet, a small group of galaxies that also includes M65 and NGC 3628. Four supernovae have been observed in M66.[5]


The colour-composite image of the Spiral galaxy M 66 (or NGC 3627)
Zooming in on the Messier 66

Gravitational interaction from its past encounter with neighboring NGC 3628 has resulted in:

  • An extremely high central mass concentration;
  • A high molecular to atomic mass ratio;
  • A resolved noncorotating clump of H I material apparently removed from one of the spiral arms.

This third result shows up visually as an extremely prominent and unusual spiral arm and dust lane structures as originally noted in the Atlas of Peculiar Galaxies.[4]


  1. ^ a b c d e f "NASA/IPAC Extragalactic Database". Results for NGC 3627. Retrieved 2006-08-31. 
  2. ^ G. de Vaucouleurs; A. de Vaucouleurs; H. G. Corwin; R. J. Buta; et al. (1991). Third Reference Catalogue of Bright Galaxies. New York:  
  3. ^ 36.2 mly × tan( 9′.1 ) = ~96 kly. radius
  4. ^ a b M66 is a member of the famous Leo Triplet a close group of galaxies that includes M65 and NGC 3628 It has a distorted appearance due to gravitational interaction with NGC 3628 and a lesser extent M65, about 800 million years ago. Zhang, Xiaolei; Wright, Melvyn; Alexander, Paul (1993). "High-Resolution CO and H i Observations of the Interacting Galaxy NGC 3627".  
  5. ^ "List of Supernovae".  

External links

  • SEDS: Spiral Galaxy M66
  • Spiral Galaxy M66
  • Astronomy Picture of the Day – Unusual Spiral Galaxy M66 from Hubble – 2010 April 13
  • Merrifield, Mike;  
  • Messier 66 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images