Messier 99 or M99 (also designated NGC 4254) is a spiral galaxy in the constellation Coma Berenices. It has an apparent visual magnitude of 9.9 and its angular diameter is 5.4x4.8 arc-minutes. M99 lies at an estimated distance of 60 million light years. The Equinox 2000 coordinates are RA= 12h 18.9m, Dec= +14° 26´ which makes M99 best seen during the spring. The Messier Spring Star Chart shows the position of all Messier objects visible during that season.
The image above shows the uncropped view of galaxies M99 (left) and M98 (right) through the Takahashi E-180 Astrograph (North is up). M98 is located to the right of the bright star (6 Comae Berenices) while galaxy M99 is to the lower left. A 3x enlargement of this image centered on M98 appears to the right.
This nearly face-on spiral galaxy was discovered by P. Méchain in 1781. It is one of the brighter spiral galaxies of the Virgo Cluster of galaxies and is unusually asymmetric.
According to Stoyan et al. (2010), the distance of M99 is 52.7 million light years and its diameter is 83,000 light years. Its estimated mass is 100 billion solar masses.
Messier's Description of M99
April 13, 1781
`Nebula without star, of a very rare [pale, faint] light, nevertheless a little clearer than the preceding [M98], situated on the northern wing of the Virgin [Virgo], and near the same star, no. 6, of the hair of Berenice [Comae Berenices]. The nebula is between two stars of seventh and of eighth magnitude. M. Méchain saw it on March 15, 1781.'
- Object: M99
- Other Names: NGC 4254
- Object Type: spiral galaxy
- Object Data: Apparent Magnitude = 9.9, Angular Size = 5.4x4.8 arc-minutes
- Object Position (Equinox 2000): RA= 12h 18.9m, Dec= +14° 26´, Constellation = Coma Berenices
- Date/Time: 2011 Apr 02 at 05:33 UTC
- Location: Bifrost Astronomical Observatory, Portal, AZ
- Mount: Astro-Physics 1200GTO
- Telescope: Takahashi Epsilon 180 Hyperbolic Astrograph
- Camera: Canon EOS 550D (Rebel T2i) (modified with a Baader UV/IR filter)
- Field of View: 1.70° x 2.56° at 1.7 arc-sec/pixel (web version: 10.0 arc-sec/pixel)
- Exposure: 4 x 300s, f/2.8, ISO 800
- File Name: M98M99-01w.jpg
- Processing (Adobe Camera Raw): Graduated Filter, Vignetting Correction, Noise Reduction, White Balance, Curves
- Processing (Photoshop CS5): Average Images, Curves, Noise Reduction
- Original Image Size: 3454 × 5179 pixels (17.9 MP); 11.5" x 17.3" @ 300 dpi
- Rights: Copyright 2011 by Fred Espenak. All Rights Reserved. See: Image Licensing.