© 2021 Michael A. Siniscalchi
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.
Wikipedia
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.
NGC4656 Hydrogen Alpha initial stretch
NGC4631 Hydrogen Alpha initial stretch
