Spiral Galaxy
NGC 5055
Canes Venatici
13H 15.8m +42° 02'

Magnitude: 8.6
Size: 10' × 6'
Distance: 37 million light-years


Requires intermediate skills

Skill Level
Although the core of M63 is easy to capture, the faint outer regions require long exposures.

MayBest Month
Tackle this target in the month of May.

Recommended Equipment
M63 is large enough to fit in the field of a fast Newtonian.

An SCT is also appropriate if you want to reveal more of the detail in M63's tight arms, but you will need to increase your exposure length to capture the faint outer regions.

Image Stats
Meade 8" SN LXD75
Meade DSI Pro III
Meade RGB + IR filters

LRGB 324:48:120:64 minutes respectively. 4-minute subs; binned 2×2 for RGB.

Average to excellent transparency
April and May 2010
San Mateo, CA

See Also
M63 (February 2005)

Galaxies come in many shapes. The strangest are of course those galaxies that have been smashed and stretched by a close encounter with a neighboring galaxy. Arp 244 is a prime example of such a cosmic collision. The most beautiful are probably those like M51 that sport ordered and symmetric spiral arms. Somewhere in between is M63.

Unlike the obvious pattern of M51, it is almost impossible to trace the arms of M63. Rather than two large arms, M63 seems to have hundreds of little arm segments, each aligned in such a way as to suggest a spiral pattern. Look at the pattern closely: you will not be surprised to hear that M63 is often called the "Sunflower Galaxy."

Why is M63 different from M51? No one knows exactly. Spiral arms are formed by density waves that propagate through the disk of the galaxy as it spins. Such a mechanism is likely to be highly sensitive to initial conditions: the speed of rotation, the amount of gas in the disk, the distribution of dark matter, etc. Perhaps M63 had more gas and a faster rotation than M51. Perhaps it was the other way around. Either way, these differences make M63, M51 and every other spiral galaxy unique—another reason why I find them so fascinating.

Imaging Notes

M63 is a bright galaxy that rewards all capture attempts, no matter the skill level. Beginners will have no problems finding it high in the sky in April, May, and June, while advanced and intermediate imagers can concentrate on maximizing depth and resolution.

Though the core and disk of the galaxy are bright, there is a faint and ragged extended halo around M63. Increase the length of your sub-exposures as much as you can to capture these areas. In particular, make sure that the straight dust lane at the southern edge of the galaxy is visible against the faint glow of the extended halo.

More Images

M63 by Chuck Domarcki

Chuck Domaracki

Meade 10" LX-200ACF — CCD-Labs Q453 — 220 minutes color (20 minute exposures)

M63 by Tom Victor Kolkin

Tom Victor Kolkin

Meade 10" LX-200ACF @f/6.8 — Artemis 4021— LRGB 70:30:30:30 (5 minute subs)

M63 by Jerry Lodriguss

Jerry Lodriguss

Astro-Physics 130EDT — Canon EOS 20Da DSLR — 120 minutes color (7.5 minute exposures)

M63 by Jean-Jacques Rapp

Jean-Jacques Rapp

Takahashi TSA102 — DSI Pro II — 230 minutes luminance (10 minute subs)

M63 by Jim Thommes

Jim Thommes

Celestron C8 f/6.7 — Artemis285 — LRGB 77:21:21:21 (7- and 3-minute subs)

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