"The Whale Galaxy is a barred spiral galaxy located at an approximate distance of 30 million light years in the constellation Canes Venatici. It has an apparent magnitude of 9.8 and appears almost edge-on. It has been nicknamed the Whale because of its elongated, slightly triangular shape that resembles the profile of the whale.
The galaxy is interacting with a smaller companion, the dwarf elliptical galaxy NGC 4627, which lies just to the north. NGC 4627 has an apparent magnitude of 13.1 and occupies an area of 2′.6 × 1′.8. The two galaxies were catalogued as Arp 281 in the Atlas of Peculiar Galaxies. The American astronomer Halton Arp, who produced the Atlas in 1966, listed the pair as an example of a galaxy pair or a “double galaxy.” The smaller galaxy is often referred to as the Pup." https://www.constellation-guide.com/whale-galaxy-ngc-4631/

"Hockey Stick Galaxy NGC 4656 is a distorted edge-on spiral galaxy located in the small northern constellation Canes Venatici, approximately 15.8 million light-years away.
The galaxy was discovered on March 20, 1787, by the British astronomer William Herschel.
This unusual shape of this galaxy is thought to be due to an interaction between NGC 4656 and a couple of near neighbors, the edge-on spiral galaxy NGC 4631 (otherwise known as the Whale Galaxy) and the small elliptical galaxy NGC 4627.
Galactic interactions can completely reshape a celestial object, shifting and warping its constituent gas, stars, and dust into bizarre and beautiful configurations." http://www.sci-news.com/astronomy/hubble-hockey-stick-galaxy-05085.html

For this project I used the only session done by Maurizio in May 8th 2021 in a mountain location close to Val'Dossola (Italy).  He only acquired the data with the L-Pro filter so I begin to process doing a normal bilinear stack.  I was surprised to get enough details in both galaxies despite it was only around 3,5 hours of data.

I rework the first process because it ended very pushed some how., Maurizio notice it and he was right!..This time obtained a soft image from both galaxies, but I also tried to do a stack in 2 drizzle and this time pay off.  The 2 drizzle give more faint details and I ended up blending four final images in one, with stacks done in DSS and Siril bilinear and 2 drizzle.

The galaxies was worked starless but getting back faint details after the use of Starnet V2 and StarXterminator.

The field where are this beautiful galaxies is plenty of a lot of little ones that enrich the view in that part of the sky.  Three hour of data are not enough for get the details that both contain, and for sure we will continue gathering data of this galaxies and  try to catch more Ha and detail.

ATLAS21dfy (AT2021biy): discovery of a transient in NGC 4631 (4 Mpc)
Searching information about this galaxies I found the marvellous work of Debra Ceravolo on Whale Galaxy, NGC 4631 with Supernova and reading it result that the session took by Maurizio was in the same period of time of her, May 2021,  so having a close look to the image, seems effectively we could catch the Supernova (or transient event) ATLAS 21dfy. In the Version part you can see the location and detail of the event in the image.

Here some links on regard the supernovae-transient event
https://www.wis-tns.org/astronotes/astronote/2021-33
https://www.wis-tns.org/object/2021biy#comment-wrapper-21191
SIMBAD
https://www.astronomerstelegram.org/?read=14360

Thank for coming to see our work.

Process end May 2022

https://twitter.com/AstroOtus/status/1532487092365938703