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Messier 95 NGC 3351
Imaged by Martin S. Ferlito copyright
Information provided by seds.org
Discovered by Pierre Méchain in 1781.
Messier 95 (M95, NGC 3351) is a beautiful barred spiral galaxy situated in
constellation Leo, and one of the fainter Messier Objects.
Pierre Méchain discovered M95, together with M96, March 20, 1781.
Consequently, Charles Messier included it in his catalog on March 24, 1781.M95 is a barred spiral of type SBb, or SB(r)ab according to de Vaucouleurs'
classification, with nearly circular arms. Alan Sandage, in the
Hubble Atlas
of Galaxies, calls it a "typical ringed galaxy". Its overall
appearance is quite similar to M91 except that M95 has more pronounced spiral
structure.
M95 is a member of the Leo I or M96 group, which also contains M96, M105 and
a number of fainter galaxies.
Barred spiral galaxy M95 was one of the galaxies in
the key project of the Hubble Space Telescope for the determination of the
Hubble constant: the HST was employed to look for Cepheid variables and thereby
determine this galaxy's distance. A preliminary result has been obtained and
published in 1996-97 by the HST H0 Key Project Team (paper VII, 1997). Their
result, corrected for the semi-recent adjustment of the Cepheid brightness zero
point by ESA's Hipparcos astrometrical satellite, is a distance of 35.5+-3.1
million light years. This is in semi-good agreement with the value of about 41
million light years (after correction for Hipparcos results) which had been
obtained earlier by Nial R. Tanvir for its neighbor M96, and implies a distance
of all the galaxies in the Leo I group of about 38 million light years.