CITSO Blog: Textures and colours of an edge-on view

NGC 4565 (the Needle Galaxy) in Coma Berenices.

Imaged April 22-24 2011, 6+ hours total.

L=150 minutes (1x1), R=70m, G=70m, B=80m (2x2). Subs=10m.

Telescope=PlaneWave CDK17, Camera=SBIG STL-4020M, Mount=Paramount ME.
PlaneWave focal reducer (f/4.5). Baader filters.

Frames acquired with TheSky 6, MaxIm DL, and Focusmax.
Processed with PixInsight and CCDInspector.

We returned to our Cabin in the Sky on Easter weekend April 22-25 2011, a trip that we had been eagerly awaiting, since the long weekend would give us an extra day to enjoy our piece of big-sky country.

Although daytime temperatures were quite mild that weekend, I had a devil of a time breaking through the thick ice on the stairway to the observatory, what had been the bottom layer, now exposed, of the four feet of snow that had piled up through the winter.

I also had a devil of a time choosing my target for imaging that weekend, with the forecast promising only one full night of clear skies, and my mind fixated on two gorgeous galaxies: the "Whale", NGC 4631, and the "Needle", NGC 4565 (or what I like to call the flying saucer galaxy). I also expected that this might be my last chance to capture either galaxy, with my family's schedule leaving few opportunities for chasing after these spring-time treasures.

The prospect of capturing the rich dust lanes, prominent buldge, and contrasting colors of the edge-on Needle with my "new" gear had been playing in the back of my mind for a long time, especially after I made a quick test shot a year ago, soon after I commissioned the "Cabin in the Sky" in May 2010. And more than three years ago, I did a one-hour exposure of this spiral galaxy, and its irregular companion NGC 4562, using my 5" Takahashi TOA-130, from the heavily light-polluted street where we lived in Vancouver at that time; needless to say, that could only reveal the general outline of both galaxies. So how could I wait another year to try for this awesome system from this spot under deep and dark skies, and with this gear, the ultimate in wish fulfillment? The Whale will have to wait until next year.

I did end up with only one full night of clear skies, that Saturday, although I squeaked in about an hour on Friday night before clouds swept in. I managed 6 hours of exposure, less time that I would have liked, but such is life, since by this time of the year, NGC 4565 transits the meridian only about an hour after the end of astronomical twilight. I got 150 minutes in unbinned luminance, and a total of 210 minutes in red, green, and blue filters, all with 2x2 binning. The scope was at about f/4,5, thanks to the PlaneWave focal reducer, giving an unbinned pixel size of about 0.78", and a total frame size of about 26' to a side.

Image processsing was done with PixInsight. This is only the 3rd image for which I used PixInsight, and by "used", I mean flat out! Which is to say, a week of deep obsession over every parameter in each one of the many astoundingly powerful processing modules that I could bring to bear. PixInsight is truly a revolution in image processing! But that is a story for another blog ;).

CITSO Blog: Textures and colours of an edge-on view

NGC 4565 in Coma Berenices

Imaged April 22-24 2011

Click the image for the high resolution version!