An ultra deep 393h look at the galaxy pair M81/M82 - Amateurs reveal full Ha stream for the first time (version with HII)

The galaxy pair Messier 81/82 is a very popular target for astrophotographers as it is fairly easy to image and contains many interesting features, such as IFN (Integrated flux nebula) and faint background galaxies. Additionally, M81 and M82 have been violently gravitationally interacting for almost 1.5 billion years. This gravitational push and pull most likely caused huge amounts of supernovae in M82’s starburst region, which are believed to ultimately fuel M82’s bipolar Ha-outflow.

 

This bipolar outflow or Ha-stream was also the main focus of our big collaboration! Having been interested in the galaxy pair for a long time, We found several deep images of the region and was especially interested in the H-alpha cap of M82 (See image). What intrigued us about this cap is that there is not really a visible connection between the main outflows of M82 and its cap. However, in some of the deepest images, it is possible to ever so slightly make out a dim connection between the main Ha stream and the Ha cap.

 

Since there exists no clear image of this region, we wanted to produce an image deep enough to reveal this exact region, which ultimately resulted in the beginning of this amazing collaboration of Astrophotographers from all over the world. In order to reveal the missing piece, we knew we had to go DEEP. Starting in February we had 6 people in the group, but the number quickly rose to now 17 people: 1 Editor, 1 person who gave us his Bortle 1 data for MSGR, and 15 photographers.

 

By mid-April we had 173h 34min of broadband data and 243h 04min of Ha data which had us confident in realizing our goal. With 416h 38min of total integration gathered on the target, of which 393h 10min (or over 16 days) were effectively used, this also marks the longest integration time ever on M81/82, and the longest one-panel integration time on Astrobin!

 

Contributers:

Carl Björk

Thomas Bähnck

Oliver Carter

Sascha Frei

Jake Gentillon

Richard Hall

Tino Heuberger

Jason Jacks

Travis Lecture

Brian Meyers

Oskari Nikkinen

William Ostling

Prashant Ranganath

Tim Schaeffer

Mark Shelton

Felix Schöfbänker

Berengar von Ow

 

Special thanks to:

William, our editor and instructor on anything processing related and who also helped compose this text. He spent a staggering 40h+ hours processing the image you see here.

Carl, who was also a great help in anything technical related and who stacked all of our over 9000+ Broadband files and 3000+ Ha files, which took over 4TB of space and several days/weeks of processing.

Mark, who stacked all of our 3000+ Ha files which again took several days and gave us a second option for the Ha-stack

Prashant, who gave us his excellent Bortle 1 data that was used for MSGR

 

For a more technical overview of the editing, please refer to Will’s website: theastroenthusiast.com/collab-processing/

 

Finally, if you want to see our image in greater detail, feel free to go to Carl’s website, where the image is uploaded in full resolution ( 6000 x 4200 px), enabling you to explore the picture by yourself and being able to zoom in on every tiny detail! On his website you'll also find every piece of equipment used, such as filters, which weren't included in this post to keep things simple.

Link to his website: elveteek.ch/m82/

Done