Spiral Galaxy M-99 (NGC 4254)

This is a 7 minute exposure with an ST-6 CCD camera taken thru Kopernik's 20-inch telescope. The field of view is about 5x7 arc minutes, with North at the top.

C. Messier: April 13th, 1781. "Nebula without a star, of very pale light, nevertheless a little clearer than the preceding, M-98. On the northern wing of Virgo and near the same star, 6 Coma Berenicis. The nebula is between two stars of 7 and 8 magnitude. M. Mechain saw it on March 15th 1781."

John Herschel: “A very remarkable object..... Bright, large, round, gradually brighter in the middle, resolvable: a three-branched spiral.”


Quote from Burnham's Celestial Handbook:

"The spiral pattern is very well defined, although somewhat asymmetric, with an unusually far-extending arm on the west side; the arms are beautifully marked by a series of bright star clouds and nebulous regions. This system has sometimes been called a 'three branch spiral', although there are only two major arms. The supposed third arm actually consists of a number of short segments which radiate out from one of the main arms of the northeast side. Thin dust lanes can be traced deep into the bright central mass, and there is a small, almost stellar nucleus.....one of the largest red shifts of any member of the Virgo Cloud."
 

Quote from The Deep Sky Field Guide to Uranometria 2000:

"Small, very bright nucleus in complex central lens with many dark lanes, two massive arms with many branches; similar to M-33....."

M-99 was discovered by Pierre Mechain in March 1781. This was the second galaxy that the Earl of Ross recognized as having a spiral structure.

• M-99, NGC 4254
• Magnitude: 10.1
• Constellation: Coma Berenices
• RA: 12h 18m 49.3s
• Dec: +14° 25' 07" (Epoch 2000)
• Size (mins): 5.4' x 4.7'
• Classification: SA(s)c


                        Spiral Galaxy, S-shaped

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George Normandin, KAS

August 15th, 2002