In the Perseus spiral arm of the Milky Way galaxy, opposite the galactic center, lies the nebula SH 2-235. As seen in visible light, SH 2-235 appears to be a small amber-colored dust cloud that spans about a tenth the size of the full moon. In infrared light, NASA's Wide-field Infrared Survey Explorer, or WISE, reveals SH 2-235 to be a huge star formation complex - more than 100 light-years across -- as seen in this new view. This image covers an area of the sky nearly five times as high and wide as the full moon (2.44 by 2.44 degrees). which is mostly light from warm dust.SH 2-235 is so named because it is a nebula found in the Sharpless Catalogue. In 1959, Stewart Sharpless from the United States Naval Observatory published a comprehensive catalogue of ionized, or charged, gas clouds, called HII regions, north of minus 27 degrees declination (declination specifies an object's location on the sky in the same way that latitude does on Earth). The Sharpless Catalogue includes many objects that are commonly known by other names, such as the great Orion nebula, or SH 2-281. However, in the case of SH 2-235, no other name exists to describe this particular region. which is mostly light from warm dust.SH 2-235 was created when two giant clouds collided. The dense material is heated by the star BD+35°1201, causing the cloud's dust to glow. SH 2-235 is part of a larger cloud complex that includes three other Sharpless HII regions (SH 231, 232, 233). This complex is interesting because it includes examples of several evolutionary stages of star development. For example, the bright orange objects on the lower right (south eastern) part of the nebula are a cluster of stars that are forming into massive stars out of cold clumps. This area is important for studying the early stages of massive star formation, which is still not well understood. which is mostly light from warm dust.Another mysterious object seen in this image is IRAS 05338+3447, the bright red object in the lower right corner. This object was seen by the Infrared Astronomical Satellite, or IRAS, as an indistinct bright spot. The WISE image shows the object much more clearly, but does not immediately reveal if it is associated with the larger star-forming region. There are also several red-colored stars in this image, which are likely young stellar objects. These are baby stars wrapped up in blankets of dust that glow brightly in infrared light which is mostly light from warm dust.Color in this image represents specific wavelengths of infrared light. Blue and cyan (blue-green) represent 3.4- and 4.6-micron wavelengths, which is primarily light emitted from hot stars. Green and red represent 12- and 22-micron wavelengths, which is mostly light from warm dust.NASA/JPL-Caltech/UCLA
Ninety-six hidden open star clusters were found in the disk of our Milky Way galaxy, astronomers said. The stars are not visible in the visible-light spectrum because they are masked by clouds of dust but the ESO's VISTRA infrared survey telescope is able to see through the massive amounts of dust.
Astronomers said that the majority of stars that are at least 50 percent larger than our sun sit within open clusters and not many of them have been detected due to massive amounts of dust and that a better read on them will facilitate insight into our galaxy.
Many of these types of clusters form in extremely dusty regions that diffuse and absorb most of the light young stars emit, researchers said.
"We found that most of the clusters are very small and only have about 10 to 20 stars. Compared to typical open clusters, these are very faint and compact objects - the dust in front of these clusters makes them appear 10,000 to 100 million times fainter in visible light. It's no wonder they were hidden," said Radostin Kurtev, a team member, in Thursday's image advisory from the ESO.
"We've just started to use more sophisticated automatic software to search for less concentrated and older clusters," lead author of the study Jura Borissova told MSNBC. "I am confident that many more are coming soon," she added.
The findings will be published in the journal Astronomy & Astrophysics.
