Image of the month: Island in Space Messier 33

About the Object

This object is a beautiful spiral galaxy known as the Triangulum galaxy as it appears in the direction of the constellation Triangulum. It is also catalogued as M33 and sometimes referred to as The Pinwheel, for obvious reasons!

This galaxy is part of our local group of galaxies which contains at least 40 ‘islands in space’. M33 is smaller than our own galaxy, the Milky Way with a mass of about one tenth.

M33 is about 3 million light years from Earth and probably influenced by the huge gravitational pull of its biggest neighbour, the Andromeda galaxy. As with all the galaxies in this group they are moving and will one day collide with each other forming new larger galaxies.

During certain times of the year M33 can be seen even from the UK with the naked eye as a fuzzy blob, but it is tough to spot.

Contained within this image you will see red areas. These are star forming regions or huge nebulae. On the upper right hand edge of the galaxy there is one such ‘blob’ which is such a large nebula that it has its own catalogue number NGC 604, despite being in another galaxy.

This is how you are seeing this object, as it was 3 million years ago, Earth time. It is interesting to think about what the Earth was like when these photons left M33 on their way to my camera to create this image you now have on your wall.

Imaging of Island in Space

To get the exquisite detail many hours of imaging is required through a range of filters. To build up to the hours required I take ‘sub frames’ or images of a shorter duration, which I can later stack together using astronomy software. In this case I used a range of exposures from 600 seconds to 1200 seconds to build up the time required to capture the detail.

I used 5 different filters, Luminance (actually this is no filter, just capturing white light), Red, Blue, Green and Hydrogen Alpha (Ha) narrowband filter.

The red, green and blue give it its colour. The luminance gives much more of the detail. The Ha filter captures the star forming regions of the nebulae within the galaxy. I then blend this Ha data with the red data to accentuate these and make them visible.

In addition to capturing the ‘light data’ at various wavelengths, many calibrations are required to create a good photograph.

There is so much to look at and enjoy in this fascinating and beautiful image. Every time I look at it I see something new. I hope you like it too and and if you would like to purchase it in one of the media then pop along to HERE   And don't forget the Autumn discount (ending 31st October 2024) of 15% - use the code GALAXY24 on check-out

Chris Baker