Categories: galaxiesObservatories

The Many Colors and Wavelengths of the Andromeda Galaxy

Andromeda is a beautiful galaxy to see with your own eyes, but in this video, ESA’s fleet of space telescopes — XMM Newton, Herschel, Planck and several ground-based telescopes — has captured M31, in different wavelengths, most of which are invisible to the eye. Each wavelength shows a different aspect of the galaxy’s nature, as well as providing a look at the lifecycle of the stars that make up Andromeda.

Visible light, as seen by optical ground-based telescopes and our eyes, reveals the various stars that shine in the Andromeda Galaxy, yet it is just one small part of the full spectrum of electromagnetic radiation.

Starting at the long wavelength end, the Planck spacecraft collects microwaves. These show up particles of incredibly cold dust, at just a few tens of degrees above absolute zero. Slightly higher temperature dust is revealed by the shorter, infrared wavelengths observed by the Herschel space telescope. This dust traces locations in the spiral arms of the Andromeda Galaxy where new stars are being born today.

The XMM-Newton telescope detects wavelengths shorter than visible light, collecting ultraviolet and X-rays. These show older stars, many nearing the end of their lives and others that have already exploded, sending shockwaves rolling through space. By monitoring the core of Andromeda since 2002, XMM-Newton has revealed many variable stars, some of which have undergone large stellar detonations known as novae.

Ultraviolet wavelengths also display the light from extremely massive stars. These are young stars that will not live long. They exhaust their nuclear fuel and explode as supernovae typically within a few tens of millions of years after they are born. The ultraviolet light is usually absorbed by dust and re-emitted as infrared, so the areas where ultraviolet light is seen directly correspond to relatively clear, dust-free parts of Andromeda.

By putting all of these observations together, and seeing Andromeda in its many different colours, astronomers are able to follow the life cycle of the stars.

You can also see Andromeda and the rest of the Universe in the various wavelengths using the Chromoscope, which is immensely fun to play around with.

Source: ESA

Nancy Atkinson

Nancy has been with Universe Today since 2004. She is the author of a new book on the Apollo program, "Eight Years to the Moon," which shares the stories of 60 engineers and scientists who worked behind the scenes to make landing on the Moon possible. Her first book, "Incredible Stories from Space: A Behind-the-Scenes Look at the Missions Changing Our View of the Cosmos" tells the stories of those who work on NASA's robotic missions to explore the Solar System and beyond.

Recent Posts

NASA Simulation Shows What Happens When Stars Get Too Close to Black Holes

What happens to a star when it strays too close to a monster black hole?…

6 hours ago

The Parker Solar Probe is getting pelted by hypervelocity dust. Could they damage spacecraft?

There’s a pretty significant disadvantage to going really fast - if you get hit with…

9 hours ago

The Decadal Survey is out! What new Missions and Telescopes are in the Works?

It’s that time again.  Once every ten years, the American astronomy community joins forces through…

9 hours ago

This is a Classic Example of a Reflection Nebula, Where the Reflected Light From Young Hot Stars Illuminates a Protostellar Cloud of Gas and Dust

The interplay of energy and matter creates beautiful sights. Here on Earth, we enjoy rainbows,…

9 hours ago

A Gravitational Lens Shows the Same Galaxy Three Times

Images from the Hubble Space Telescope are often mind-bending in both their beauty and wealth…

15 hours ago

NASA Launches DART, to Learn how to Defend the Earth From a Future Asteroid Impact

NASA's Double Asteroid Redirection Test (DART) just launched and will intercept a Near-Earth Asteroid (NEA)…

1 day ago