Messier 63
Also known as NGC 5055 or Sunflower Galaxy, is a spiral galaxy in the northern constellation of Canes Venatici with approximately 400 billion stars. In the mid-19th century, Anglo-Irish astronomer Lord Rosse identified spiral structures within the galaxy, making this one of the first galaxies in which such structure was identified.
The shape or morphology of this galaxy has a classification of SAbc, indicating a spiral form with no central bar feature (SA) and moderate to loosely wound arms (bc). In the past it was considered a flocculent galaxy even if the spiral arms are clearly visible in optical images like our picture here. When observed in the near infrared, an even more evident symmetric, two-arm structure is seen - you can see it here in the IR Spitzer blend image, Revision D, that appears as a mouse-over of Final Revision C.
Radio observations at the 21-cm hydrogen line show the gaseous disk of M63 extends outward to a radius of 130,000 light-years, well past the bright optical disk. This gas shows a symmetrical form that is warped in a pronounced manner, starting at a radius of 33 kly. The form suggests a dark matter halo that is offset with respect to the inner region. The reason for the warp is unclear, but the position angle points toward the smaller companion galaxy, PGC45992 (top right of center in the wide-field image, Revision A) .
There is a great variability in the distance estimates from 16 to 34 Mly. M63 is part of the M51 Group (the 'Whirlpool Galaxy').
(source wikipedia, simbad)

PGC46386
The most recent distance estimation calls for a distance of 58 Mly.

PGC46093
It is an Active Galaxy Nucleus Candidate, 26.7 Mly away.

2MFGC10580
The short diagonal line seen on the lower right side of the galaxy's disk is actually a much more distant galaxy, oriented with its edge facing toward us.

Spitzer Observation: March 3rd, 2011, sig11-002
Blue shows infrared light with wavelengths of 3.6 microns, green represents 4.5-micron light and red, 8.0-micron light. The contribution from starlight measured at 3.6 microns has been subtracted from the 8.0-micron image to enhance the visibility of the dust features.
(from spitzer.caltech.edu)