Click here for a large wide-field image of M-94.
Quote from the Deep Sky Field Guide to Uranometria 2000:
Extremely bright nucleus in bright
inner ring, very many smooth arms in lens 6.0x4.7 arc minutes.
Charles Messier (March 24th, 1781):
“Nebula without star above Charles' Heart. On the same parallel as the
star beta. It is brilliant in the center and the nebulosity is a little
diffuse. It resembles the nebula which is below Lepus, No.
79, but is finer and brighter. M. Mechain made its discovery on Mar.
Quote by William Parsons, Earl of Rosse (April 13th, 1855): “A dark ring round the nucleus; then bright ring exterior to this. The annulus however is not perfect, but broken up and patchy, and the object will probably turn out to be a spiral. Much faint outlying nebulosity.”
M 94 is a face-on Spiral Galaxy in the Constellation of Canes Venatici. The range of surface brightness between the nuclear region and the outer regions is very great. The intense very small nucleus is devoid of spiral structure. Tightly wound spiral arms begin tangent to this amorphous central region and wind out through a region of lower surface brightness of lens shape. A third region, filled with spiral arms, begins at the outer boundary of the second zone. As between the first and second zones, a sharp discontinuity of surface brightness exists between the second and third zones. The surface brightness of the third zone appears to go to zero rather suddenly. An annular zone devoid of luminosity then begins. This zone of near zero surface brightness continues until the inner boundary of a faint external ring is reached at 260 sec of arc radius from the nucleus. Unfortunately, this ring is too dim to show in the Kopernik image above.
M-94 has an Active Galactic Nucleus that the Hubble Space Telescope shows to be a double source. This has led to recent suggestions that M-94 is a merger of two galaxies.
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George Normandin, KAS
May 10th, 2001