Swift satellite images a galaxy ablaze with starbirth

February 26, 2008
Swift satellite images a galaxy ablaze with starbirth
Image credit: NASA/Swift Science Team/Stefan Immler

Combining 39 individual frames taken over 11 hours of exposure time, NASA astronomers have created this ultraviolet mosaic of the nearby "Triangulum Galaxy." "This is the most detailed ultraviolet image of an entire galaxy ever taken," says Stefan Immler of NASA's Goddard Space Flight Center in Greenbelt, Md. Immler used NASA's Swift satellite to take the images, and he then assembled them into a mosaic that seamlessly covers the entire galaxy.

The Triangulum Galaxy is also called M33 for being the 33rd object in Charles Messier's sky catalog. It is located about 2.9 million light-years from Earth in the constellation Triangulum. It is a member of our Local Group, the small cluster of galaxies that includes our Milky Way Galaxy and the Andromeda Galaxy (M31). Despite sharing our Milky Way's spiral shape, M33 has only about one-tenth the mass. M33's visible disk is about 50,000 light-years across, half the diameter of our galaxy.

Swift's Ultraviolet/Optical Telescope (UVOT) took the images through three separate ultraviolet filters from December 23, 2007 to January 4, 2008. The mosaic showcases UVOT's high spatial resolution. Individual star clusters and star-forming gas clouds are clearly resolved, even in the crowded nucleus of the galaxy. The image also includes Milky Way foreground stars and much more distant galaxies shining through M33.

Young, hot stars are prodigious producers of ultraviolet light, which heat up the surrounding gas clouds to such high temperatures that they radiate brightly in ultraviolet light. The image shows the giant star-forming region NGC 604 as a bright spot to the lower left of the galaxy's nucleus. With a diameter of 1,500 light-years (40 times that of the Orion Nebula), NGC 604 is the largest stellar nursery in the Local Group.

"The ultraviolet colors of star clusters tell us their ages and compositions," says Swift team member Stephen Holland of NASA Goddard. "With Swift's high spatial resolution, we can zero in on the clusters themselves and separate out nearby stars and gas clouds. This will enable us to trace the star-forming history of the entire galaxy."

"The entire galaxy is ablaze with starbirth," adds Immler. "Despite M33's small size, it has a much higher star-formation rate than either the Milky Way or Andromeda. All of this starbirth lights up the galaxy in the ultraviolet."

Larger image: www.nasa.gov/images/content/214434main_M33_UVOT.jpg

Source: Goddard Space Flight Center, by Robert Naeye

Explore further: Inferring the star formation rates of galaxies

Related Stories

Inferring the star formation rates of galaxies

November 23, 2015

Our Milky Way galaxy produces on average a few new stars every year across the entire system. Massive young stars emit large amounts of ultraviolet radiation which heats the local dust, and so the star formation process results ...

Launch of Astrosat first Indian astronomy satellite

September 28, 2015

The first Indian astronomy satellite Astrosat was launched on 28th September, 2015, by the Indian Space Research Organisation (ISRO) from Sriharikota, on a PSLV (Polar Satellite Launch Vehicle) rocket. Astrosat has unprecedented ...

The sun

September 28, 2015

The sun is the center of the Solar System and the source of all life and energy here on Earth. It accounts for more than 99.86% of the mass of the Solar System and it's gravity dominates all the planets and objects that orbit ...

Hubble sees a galaxy with a glowing heart

July 14, 2014

(Phys.org) —This view, captured by the NASA/ESA Hubble Space Telescope, shows a nearby spiral galaxy known as NGC 1433. At about 32 million light-years from Earth, it is a type of very active galaxy known as a Seyfert galaxy—a ...

Amazing Andromeda Galaxy

October 3, 2006

The many "personalities" of our great galactic neighbor, the Andromeda galaxy, are exposed in this new composite image from NASA's Galaxy Evolution Explorer and the Spitzer Space Telescope.

Recommended for you

Earth might have hairy dark matter

November 23, 2015

The solar system might be a lot hairier than we thought. A new study publishing this week in the Astrophysical Journal by Gary Prézeau of NASA's Jet Propulsion Laboratory, Pasadena, California, proposes the existence of ...

The hottest white dwarf in the Galaxy

November 25, 2015

Astronomers at the Universities of Tübingen and Potsdam have identified the hottest white dwarf ever discovered in our Galaxy. With a temperature of 250,000 degrees Celsius, this dying star at the outskirts of the Milky ...

Scientists detect stellar streams around Magellanic Clouds

November 23, 2015

(Phys.org)—Astronomers from the University of Cambridge, U.K., have detected a number of narrow streams and diffuse debris clouds around two nearby irregular dwarf galaxies called the Magellanic Clouds. The research also ...


Adjust slider to filter visible comments by rank

Display comments: newest first

5 / 5 (1) Feb 26, 2008
I can't wait until the James Webb Telescope goes into orbit in 2013. Hubble is scheduled for major upgrades this fall which will hold us over until then.
5 / 5 (1) Feb 26, 2008
JWST will image a different section of the spectrum that either Hubble or Swift. So it's not a replacement for either of them, it's a complementary telescope. Herschel will also be up this year (3.5 metre mirror) for sub-millimetre and far infrared stuff.


There are many different wavelengths to observe, and one telescope can't do them all. You need many different telescopes to see in every wavelength.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.