Object of the Month – The Andromeda Galaxy

Each month I will focus on one object which is available in the Galaxy on Glass range. This month I have chosen the beautiful galaxy Andromeda

My image of the Andromeda Galaxy

What is it?

Andromeda is what we call a galaxy – a huge collection of stars, their planets, dust and gasses held together by gravity. Galaxies are also thought to have a black hole at their centre.

Our own Milky Way is also a galaxy.

Andromeda is classified as a spiral galaxy – you can see this from the image! The galaxy is estimated to comprise close to 1 trillion stars, or more precisely Solar Masses. This makes it many times larger than the Milky Way.

Galaxies clump together in space with Andromeda being the largest of a group of about 50 galaxies. Our Milky way is the second largest.

Andromeda is the closest spiral galaxy to us at about 2.5 million light years. We are rapidly moving toward each other and one day, not any time soon, we will combine to become one galaxy.

In this image you can also see two other galaxies which are locked to Andromeda through gravitational interactions.

The larger one of the two is classified as Messier 110 and is a dwarf elliptical galaxy with an estimated 10 billion stars. (Compare this with the Milky way with an estimated 100 Billion stars)

Galaxy M110

The smaller one, which appears closer to Andromeda, is classified as Messier 32 and is also a dwarf galaxy- it’s shape heavily distorted by the presence of its huge neighbour.

Messier 32 Galaxy

Imaging Andromeda

Unlike many of the objects I image, this is really quite bright, relatively speaking!

Nevertheless, 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 30 seconds to 150 seconds to build up the time required to capture the detail. The total was in the region of 20 hours.

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

The red, green and blue give it its colour. The luminance gives much more of the detail. The Hydrogen Alpha filter captures the star forming regions. I blended this data into the red channel.

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

‘Andromeda and Friends’ is available in the Chris Lintott Collection in limited editions. It can be purchased as Frameless acrylic or as framed and backlit – both look spectacular!