Edge-On Lenticular (Spiral?) Galaxy in Draco

Click here for uncropped versions:  40%, uncropped (1610x1612) 65%, uncropped (2617x2620) 100%, uncropped (4026x4031)


NGC5866: This is a magnitude 10.7 lenticular (maybe; see next sentence) galaxy (essentially, a spiral galaxy without arms) in Draco, presenting to us edge-on. "Maybe" because of the prominent dust lane that bisects the galaxy, which is highly unusual for a lenticular galaxy; there is thought that NGC5866 actually is a spiral galaxy (which would explain the dust lane), that collided with another galaxy, resulting in this unusual shape (with the stars puffing out above and below the galactic plane). It is thought by many that NGC5866 also is M102, but that is uncertain. The prominent dust lane almost bisects the disc, with a very slight angle from the long axis of the galaxy. It is estimated to be approximately 44 million light years from earth, and approximately 60,000 light years in diameter (a little over half that of our Milky Way galaxy), with a mass about the same as our Milky Way. NGC5866 is part of a galaxy group which includes NGC5907.

This galaxy has a small apparent size due to its distance; I also have presented the photo in a few uncropped versions, which I like because of all the interesting things (mostly small background galaxies) any wife-field image shows.

A bizarre thing, to me, about this galaxy is that very, very few images (not even imagages taken with Spitzer and Hubble) show the halo that surrounds the galaxy, even though the structure is evident even on my integrated luminance image before any post-processing.

This is the second time I have imaged this target. I had imaged it seventeen years earlier from my yard. If you want to compare that image to this one (to see what much darker skies, better equipment, and (hopefully) more skill can do, click here.


Technical Information:

LRGB: 1080:240:180:240 (Luminance images were a blend of 20 thirty-minutes images and 32 fifteen-minute images; R and G images all fifteen minute unbinned images; B were twenty minute unbinned images).

Equipment: RC Optical Systems 14.5 inch Ritchey-Chretien carbon fiber truss telescope, with ion-milled optics and RCOS field flattener, at about f/9, and an SBIG STX-16803 with internal filter wheel (SBIG filter set), guided by an SBIG AO-X, all riding on a Bisque Paramount ME German Equatorial Mount.

Image Acquisition/Camera Control: Maxim DL, controlled with ACP Expert/Scheduler, working in concert with TheSky X.

Processing: All images calibrated (darks, bias and sky flats), aligned, and combined in Pixinsight. Color combine in Pixinsight. Some finish work (background neutralization, color calibration, gradient removal, Multiscale Linear Transform, lessening the dynamic range) done in Pixinsight; some finish work (Neat Image noise reduction, Smart Sharpening, LRGB combination, contrast and saturation adjustment) was done in Photoshop CC.

Location: Data acquired remotely from Sierra Remote Observatories, Auberry, California, USA.

Date: Images taken on many nights in June and July of 2020. Image posted July 22, 2020.

Date: Image scale of full-resolution image: 0.56 arcseconds per pixel.

Seeing: Generally excellent, with calibrated luminance images varying from 1.3 to 1.9 arcsecond FWHM

CCD Chip temperature: -25C

Copyright 2020 Mark de Regt

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