Image Tour: Dwarf Galaxy NGC 4449

Produced by the Space Telescope Science Institute’s Office of Public Outreach in collaboration with NASA’s Universe of Learning partners: Caltech/IPAC, Center for Astrophysics | Harvard & Smithsonian, NASA Jet Propulsion Laboratory, and Sonoma State University

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 Text, Image Tour, N G C 4 4 4 9. 

Fast Facts. Location, Constellation Canes Venatici. Distance From Earth, 12.5 million light-years. Size, 19,000 light-years across. Telescope, Hubble Space Telescope. 

The galaxy N C G 4 4 4 9 is a dwarf galaxy. Dwarf galaxies are collections of several billion stars, a much smaller number than the hundreds of billions present in a galaxy like our Milky Way. 

N C G 4 4 4 9 is about 10 percent the size of the Milky Way. All across the galaxy we see evidence of an abundance of star formation. 

A bar appears at the bottom. Text, Tour Stops. Irregular Galaxy, Galaxy Core, Star Formation, Foreground Objects, Background Stars. A box highlights the first stop, Irregular Galaxy. 

N C G 4 4 4 9's chaotic shape classifies it as an irregular galaxy. This means it lacks the well-defined structure of the spiral or elliptical galaxies. Two photos appear and are labeled spiral galaxy N G C 5 4 5 7 and Elliptical Galaxy N G C 1 1 3 2, respectively. 

The box on the tour bar highlights the next stop, Galaxy Core. Text, The central region of N G C 4 4 4 9 contains a bright white knot of stars with a dark cloud to the left. This dark spot is an example of a dense cloud of gas that does not glow on its own and is seen in a shadow against the brighter background. 

In the top left corner, a white box highlights the section of the galaxy we see close up on the right. 

Text, Stars can form within these gas clouds. 

The box on the tour bar highlights the next stop, Star Formation. Four pink glowing areas are circled on the photo. 

Text, the bright pinkish regions shown here are sites where stars are being born. 

The radiation of hot young stars heats the surrounding gas until it glows. 

The pink emission from heated hydrogen gas is generally a telltale sign of active star formation. 

The box on the tour bar highlights the next stop, Foreground Objects. A bright star is circled in white. 

Text, We look out at distant galaxies through the stars of our Milky Way. The star's spiky appearance is caused by the telescope and indicates that the star is within our galaxy. 

The box on the tour bar highlights the next stop, Background Stars. A reddish galaxy is circled in white. 

Text, Many more distant galaxies exist beyond N GC 4 4 4 9. In the background of this image we see a faraway spiral galaxy. 

The text and circle fade, then the tour stops reappear in a bar across the bottom. Text, irregular galaxy, galaxy core, star formation, foreground objects, background stars.