star formation tagged posts

A NASA/ESA Hubble Space Telescope view of the spiral galaxy NGC 7714, which has been dramatically distorted in shape by a close interaction with another nearby galaxy. Minor, but frequent, disturbances such as this cause a burst of star formation, accounting for around half of all new stars being formed in the local Universe. Credit: NASA/ESA

Around half of the star formation in the local Universe arises from minor mergers between galaxies, according to data from the Sloan Digital Sky Survey. The patch of sky called Stripe 82 is observed repeatedly to produce high-quality images of spiral galaxies...

UGC 4879 is an irregular dwarf galaxy Credit: NASA/ESA

The drizzle of stars scattered across this image forms a galaxy known as UGC 4879. UGC 4879 is an irregular dwarf galaxy—as the name suggests, galaxies of this type are a little smaller and messier than their cosmic cousins, lacking the majestic swirl of a spiral or the coherence of an elliptical.

This galaxy is also very isolated. There are about 2.3 million light years between UGC 4879 and its closest neighbor, Leo A, which is about the same distance as that between the Andromeda Galaxy and the Milky Way. This galaxy’s isolation means that it has not interacted with any surrounding galaxies, making it an ideal laboratory for studying star formation uncomplicated by interactions with other galaxies...

The Spider Nebula lies about 10,000 light-years away from Earth and is a site of active star formation. Infrared wavelengths have been assigned visible colors. Light with a wavelength of 1.2 microns, detected by 2MASS, is shown in blue. The Spitzer wavelengths of 3.6 and 4.5 microns are green and red, respectively. Credit: NASA/JPL-Caltech/2MASS

A nebula known as “the Spider” glows fluorescent green in an infrared image from NASA’s Spitzer Space Telescope and the Two Micron All Sky Survey (2MASS). The Spider, officially named IC 417, lies near a much smaller object NGC 1931. Together, the two are called “The Spider and the Fly” nebulae. Nebulae are clouds of interstellar gas and dust where stars can form.

The Spider, ~10,000 light-years from Earth in the constellation Auriga, is clearly a ...

Credit: ESA/Hubble and NASA; Acknowledgement: Judy Schmidt

Despite being less famous than their elliptical and spiral galactic cousins, irregular dwarf galaxies, such as the one captured in this NASA/ESA Hubble Space Telescope image, are actually one of the most common types of galaxy in the universe. Known as UGC 4459, this dwarf galaxy is located 11 million light-years away in constellation of Ursa Major (The Great Bear), a constellation that is also home to the Pinwheel Galaxy (M101), the Owl Nebula (M97), Messier 81, Messier 82 and several other galaxies all part of the M81 group.

UGC 4459’s diffused and disorganized appearance is characteristic of an irregular dwarf galaxy...