Messier 51

What a ride!

This photo tooke over 15 nights of data gathering to complete! With nights getting really short during summer here, I can only take around 2-3 hours of data per night mid summer. But the result was well worth the effort.

Take a look at the full resolution image and note the annotations that show galaxies down to a magnitude of 19.0. There are so many faint / distant galaxies in the background of the image, some of them with quite the high redshift!

Messier 51

M51 is a spiral galaxy, that has been interacting with its smaller neighbor NGC5195 for the past 100’s of millions of years. During this gravitational interaction a lot of star systems were ejected out of the galaxies. These are visible as grayish streams flowing outwards from the two galaxies. One of the arms from M51 can even be seen as connecting to the passing galaxy (NGC5195). Note that NGC5195 has actually been determined to be passing the behind M51 from our point of view.

The pair of galaxies is located roughly 30 million Lightyears from earth.

A pair of interacting galaxies

Messier 51 is probably one of the most studied pair of intergalactic galaxies in the science community. It’s (relativly speaking) close proximity to earth and head on orientation in space allows for very detailed imaging and detailed studies.

From simulations trying to simulate this interacting pair of galaxies the theory grew that this is actually not the first pass of the two galaxies but that they have actually interacted before, flew away from each other again, only for the two galaxies to fall towards each other again. Be aware that we are talking in the time frames of 100’s of million of years for those multiple interactions.

The core

The galaxy M51 features very prominent spiral arms. Fine dust lanes (dark / black) can be seen traveling along those arms towards the center / core of the galaxy. The blue colors indicate areas of stars formation (young stars) while the yellowish color hints at older stars with areas of less / no star formation.

What looks like red dots in the arms is actually ionised hydrogen, usually this hints at very active star formation regions.

Processing

For this photo I used a few new processing techniques. For the first time I used an AI aided tool to subtract the stars from the image in order to be able to process the non-stellar details and the stars on their own. This really helped with being able to work on the details of the galaxy with denoising and sharpening tools, without having to worry about the stars turning ugly.

Further, using the Spectrophometric Color Calibration tool was a first for me. It yielded really accurate colors that match the real colors of the galaxies and stars.