Chosen as Astronomy Magazine's Picture of the Day for April 11, 2017

In another wonderful example of what surprises lie beyond the camouflage of our night sky, the spiral galaxy M63 pops with some of the richest features in our sky.  Named the Sunflower Galaxy after its mottled yellow core's likeness to the center disc flower of the common sunflower, this 37 million light-year-distant galaxy displays countless dark dust lanes interspersed between its splendidly colored arms.  At a diameter 135,000 light years, this is a mammoth galactic flower, coming in roughly 30% larger than our own Milky Way.  Things this size usually boast an appetite, and we've nearly caught this cosmic blossom in the act!

Close viewing of this image on a bright monitor (or alternatively, viewing of the inverse process of the luminance channel) shows a faint loop around the galaxy, bulging outward from the top-left of the disc.  This feature, called a tidal loop, is a vestige of a galactic feast in which the Sunflower Galaxy pulled in a smaller dwarf satellite galaxy, a banquet that we've just missed on the universal clock, having occurred within the last 5 billion years.  These tidal tendrils, first identified in 1979, were only confirmed to be a remnant of M63 activity in 2011, and today we remain uncertain as to the current position or final destiny of the small galactic morsel that left this trail of evidence in its wake.

Having taken this photo myself in 2016, it's hard not to glean a sense of pioneering -- We are truly on the edge of exploration when peering into the universe!  "New lands" like these tidal plumes are incredibly dim.  Getting enough contrast in the exposures for features like this is difficult, as it is, even from the best and darkest skies, and is far more so in the presence of even moderate light pollution.  Every bit of the 20+ hours of exposure taken for this image were helpful in contributing detail to the tidal trails, but the fact we can do this is really a testament to the power and advantage long-exposure photographs have by collecting photons over minutes, hours, and in this case, nights.  Piece by piece, we continue to discover the story of the cosmos this way, and continue to understand how much more there is yet to find!