M 95 & 96 with Celestron 80mm APO Refractor Click on photo to return to 'Galaxies' Home
M96 NGC3368 M95 NGC3351
Dreyer description: Very bright, very large, little extended, very abruptly very much brighter middle, Dreyer description: Bright, large, round, pretty gradually
resolvable, but mottled; = M96. much brighter middle nucleus; = M95.
Magnitude: 9.9 Magnitude: 10.7
RA: 10h 46m 45.2s Dec: +11°49'16" (Epoch 2000) RA: 10h 43m 58.0s Dec: +11°42'15" (Epoch 2000)
Rise: 20:11 Transit: 02:57 Set: 09:38 Rise: 20:09 Transit: 02:54 Set: 09:35
Size: 7.5' x 5.2' Size: 7.4' x 5.0'
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 ~nrt/"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.
Discovered by Pierre Méchain in 1781.
Messier 96 (M96, NGC 3368) is a conspicuous spiral galaxy in constellation Leo.
M96 is the brightest member of the Leo I group of galaxies, which is therefore also called the M96 group, and also includes M95, M105 as well as a number of fainter galaxies.
Pierre Méchain discovered M96, together with M95, on March 20, 1781. Consequently, Charles Messier included it in his catalog on March 24, 1781. It was among the first spirals that have been discovered, and listed by Lord Rosse as one of 14 "spiral nebulae" discovered to 1850.
Its distance was determined to be about 41 million light years (after corrections for the distance scale which are implied by the results of ESA's Hipparcos satellite) by ~nrt/"Nial R. Tanvir with the Hubble Space Telescope by observing Cepheid variables. Interpolated with the HST result of 35.5 million light years for its neighbor M95, we adopt a value of 38 million light years here for the whole group.
At this distance, the apparent diameter of its brighter central region, 6 arc minutes, corresponds to a linear dimension of 66,000 light years. However, as can be seen e.g. in the Digital Sky Survey image, or the Hubble Atlas of Galaxies, this galaxy has faint extensions, an outer ring of filaments (spiral arm fragments), which are connected to the bright visible part near the northwest end of the major axis. This ring has a diameter of at least about 9 arc minutes in the DSS image, corresponding to about 100,000 light years.
The apparent visual brightness of 9.2 magnitudes corresponds to an absolute magnitude of -21.1.
According to J.D. Wray's Color Atlas of Galaxies, the bright inner disk is composed of a smooth yellow stellar population of old stars, which ends slightly beyond a ring of blue knots. These knots are probably clusters of young, hot stars. As visible in our image, this galaxy contains a significant amount of dust, which is apparently more concentrated on the left side in our image. It is common that dust appears with greater contrast on the near side of a galaxy than on the far side, so this asymmetry indicates that the near side of M96 is on the left in our image.
TELESCOPE: 80 mm Celestron APO F/8
CAMERA: 'SBIG' ST-8XE & CFW8 color filter wheel
CAMERA TEMP: Temp. = -18 C
Processing: MaxIm; calibrate, DeBloom (Ron Wodaski), color combine, CCDstack align, Photoshop CS2