Royal Astronomical Society | 2015 Feb 27
Brazilian astronomers have made a remarkable discovery: a cluster of stars forming on the very edge of the Galaxy. ...
Negative WISE W1 images of the newly found clusters Camargo 438 (left) and Camargo 439 (right).
The clusters are about 16,000 light years away, so the images are about 24 light years across.
The black dots in the images are individual stars. (Credit: D. Camargo/NASA/WISE)
The Milky Way, the Galaxy we live in, has a barred spiral shape, with arms of stars, gas and dust winding out from a central bar. Viewed from the side, the Galaxy would appear relatively flat, with most of the material in a disc and the central regions.
Stars form inside massive and dense clumps of gas in so-called giant molecular clouds (GMCs) that are mainly located in the inner part of the galactic disc. With many clumps in a single GMC, most (if not all) stars are born together in clusters.
Denilso’s team looked at data from NASA’s orbiting Wide-Field Infrared Survey Explorer (WISE) observatory. They not only found GMCs thousands of light years above and below the galactic disc, but that one of them unexpectedly contained two clusters of stars. This is the first time astronomers have found stars being born in such a remote location.
The new clusters, named Camargo 438 and 439, are within the molecular cloud HRK 81.4-77.8. This cloud is thought to be about 2 million years old and is around 16000 light years beneath the galactic disk, an enormous distance away from the usual regions of star formation, in the direction of the constellation of Cetus. ...
Discovery of two embedded clusters with WISE in the high Galactic latitude cloud HRK 81.4-77.8 - Denilso Camargo et al
- Monthly Notices of the RAS 448(2) 1930 (2015 Apr 01) DOI: 10.1093/mnras/stv092
arXiv.org > astro-ph > arXiv:1501.03707 > 15 Jan 2015