2021 Michael A. Siniscalchi


What's New



Odds n Ends

    NGC 4631 & NGC 4656
     Barred Spiral Galaxies in Canes Venatici     
      NGC 4631 RA:12h 42m 50s  Dec: +32 33' 15"  Distance - 30 mly Size - 15.5'x7'
       NGC 4656 RA:12h 42m 59s  Dec: +31 57' 43" Distance - 23 mly  Size - 8.4'x6.6'

Click on image for larger size.

   The top galaxy in this image is NGC 4631 (also known as the Whale Galaxy or Caldwell 32) is a barred spiral galaxy in the constellation Canes Venatici. This galaxy's slightly distorted wedge shape gives it the appearance of a herring or a whale, hence its nickname. NGC 4631 also contains a central starburst, which is a region of intense star formation. The strong star formation is evident in the emission from ionized hydrogen and interstellar dust heated by the stars formed in the starburst.The most massive stars that form in star formation regions only burn hydrogen gas through fusion for a short period of time, after which they explode as supernovae. So many supernovae have exploded in the center of NGC 4631 that they are blowing gas out of the plane of the galaxy. This superwind can be seen in X-rays and in spectral line emission. The gas from this superwind has produced a giant, diffuse corona of hot, X-ray emitting gas around the whole galaxy
   NGC 4631 has a nearby companion dwarf elliptical galaxy, NGC 4627. NGC 4627 and NGC 4631 together were listed in the Atlas of Peculiar Galaxies as an example of a "double galaxy" or a galaxy pair

NGC 4656/57 is a highly warped barred spiral galaxy located in the constellation Canes Venatici and is sometimes informally called the Hockey Stick Galaxies or the Crowbar Galaxy. This unusual shape is thought to be due to an interaction between NGC 4656, NGC 4631, and NGC 4627.
Location & Date
Backyard, Abbott Observatory- Long Island, NY,  April 2021
TMB130SS F/7 APO, Moonlite focuser, Losmandy G11 Gemini
Image scale 1.54 arcsec/pixel
Baader  Ha L R G B  filters
CCD temp -15C
Ha 12x10m   Lum 45x5m  Red-12x10m Green -12x10m Blue-12x10m   Bin 1x1 for each 2 mosaic panel
Planning & Acquisition
Image planning - Sequence Generator Pro mosaic tool. This is a two panel mosaic.
Image acquisition - Sequence Generator Pro w/PinPoint & PHD2 (guiding)
CCDStack - calibration, debloom, deconvolution
Astro Pixel Processor - align, normalize, combine, stitch mosaic panels, RGB combine
Adobe Photoshop - Ha blending into red channel, Noise reduction, JPEG conversion
Topaz Sharpen AI and Gigapixel AI - finer detail processing
NGC4656 Hydrogen Alpha initial stretch
NGC4631 Hydrogen Alpha initial stretch