M64 - Spiral Galaxy in Coma Berenices

M64_LRGB_AP155


Click on the image for a close-up!

M64 - Spiral Galaxy in Coma Berenices
Mag 8.5 RA 12:56.7 Dec +21 41
9.3 x 5.4 arcminutes
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From SEDS.ORG:

Discovered 1779 by Edward Pigott.

M64 is the famous Black Eye galaxy, sometimes also called the "Sleeping Beauty galaxy". The conspicuous dark structure is a prominent dust feature obscuring the stars behind. This feature also enables one to determine, or at least estimate, which of the galaxy's sides is nearer and which more remote; in case of M64, it seems that the southern side is nearer to us.

The dust feature is well visible even in smaller telescopes. M64 was recently shown to have two counterrotating systems of stars and gas in its disk: The inner part of about 3,000 light years radius is rubbing along the inner edge of the outer disk, which rotates opposite and extends up to at least 40,000 light years, at about 300 km/sec. This rubbing process is probably the reason for the observed vigorous star formation process, which is currently under way, and can be observed as the blue knots imbedded in the peculiar dust lane on one side of the nucleus. It is speculated that this peculiar disk and dust lane may be caused by material from a former companion which has been accreted but has yet to settle into the mean orbital plane of the disk.

M64 was discovered by Edward Pigott on March 23, 1779, just 12 days before Johann Elert Bode found it independently on April 4, 1779. Roughly a year later, Charles Messier independently rediscovered it on March 1, 1780 and cataloged it as M64. However, Pigott's discovery got published only when read before the Royal Society in London on January 11, 1781, while Bode's was published during 1779 and Messier's in late summer, 1780. Pigott's discovery was more or less ignored and recovered only by Bryn Jones in April 2002!

The dark dust feature was discovered by William Herschel who observed M64 twice in 1785 and 1789, and already compared it to a "Black Eye."

The distance of this galaxy seems to be not very well determined. A new press release from the Space Telescope Science Institute (STScI PRC 99-10) gives the distance of M64 as 19 million light years, a value we adopt here for now.

Adopting this distance, the apparent extension of M64 of 9.3 arc minutes corresponds to a linear diameter of about 51,000 light years, and its visual magnitude of 8.5 to an absolute magnitude of -20.3 (uncorrected for absorption which is low at the galaxy's high galactic latitude).

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ST-10XME and CFW8a Astrodon LRGB
AP155EDF F/7
Self-guided on AP900 GTO  
Luminance 18 x 5 min = 90 min
RGB 3 x 10 min per channel = 30 min / channel
Acquisition, Darks, Flats in CCDSoft5
Aligned and combined in Maxim
Colour combines, Levels and Curves in PS CS2
Luminance layered in twice at 50% with saturation boost
Gradient removal using Russ Croman's Photoshop Plug-in GradientXTerminator
Colour noise reduction using Reduce Noise filter in PS CS2

The moon rose during the second set of luminance frames but the gradient removal seemed to address any concerns

Click on the image to see a crop of the galaxy alone.

Flesherton, Ontario
March 29 2008

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