No doubt, naked-eye views of the universe are spectacular, but there's much more going on out there than appears in visible light. That's why astronomers routinely observe with a variety of telescopes equipped to capture multiple wavelengths of light across the electromagnetic spectrum.
To showcase how these different wavelengths highlight particular features and processes in the lifecycle of stars, the European Space Agency trained their fleet of space telescopes on the Andromeda Galaxy, also known as M31, and compiled the observations into this video.
To get the star party started, the video shows where the Andromeda Galaxy is in an optical – visible light view – of the night sky and then zeros in on it with a microwave view from the Planck spacecraft. Microwaves are at the long-wavelength end of the spectrum and are sensitive to particles of extremely cold dust – just a few tens of degrees above absolute zero.
After a shift to a close-up optical shot of the galaxy, located about 2.5 million light years away, we are treated to an infrared view observed by the Herschel space telescope, which highlights slightly warmer dust. This dust traces locations in the spiral arms of Andromeda where new stars are being born today, the ESA notes in a media advisory.
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 through space. ESA has used this telescope to monitor the core of Andromeda since 2002, revealing many variable stars, some which have exploded as novae.
The ultraviolet views display light from extremely massive, young stars that have a relatively short life span: They exhaust their nuclear fuel and explode as supernovae typically within a few tens of millions of years after they are born. Ultraviolet light is usually absorbed by dust and re-emitted as infrared. That means the areas where ultraviolet light is directly seen are relatively clear, dust free regions of Andromeda.
For more on the Andromeda Galaxy, check out these stories below.
- Andromeda's once and future stars
- The galaxy next door
- Andromeda is a cannibal and heading our way
- NASA captures amazing view of Andromeda
- Andromeda involved in galactic collision
John Roach is a contributing writer for msnbc.com. Connect with the Cosmic Log community by hitting the "like" button on the Cosmic Log Facebook page or following msnbc.com's science editor, Alan Boyle, on Twitter (@b0yle).
