Rosette Baby Boom

April 12, 2010 14:48 by scibuff

The latest image of the Rosette Nebula taken by the Herschel Space Observatory reveals previously unseen stars with up to ten times the mass of our Sun. The image is a combination of three different wavelength from the infrared part of spectrum: at 70 microns (blue), 160 microns (green) and 250 microns (red. The raw data was acquired by Herschel’s Photoconductor Array Camera and Spectrometer (PACS) and the Spectral and Photometric Imaging Receiver (SPIRE).

The Rosette molecular cloud, seen by Herschel

Infrared image of the Rosette molecular cloud in a three-colour composite made with observations from Herschel’s Photoconductor Array Camera and Spectrometer (PACS) and the Spectral and Photometric Imaging Receiver (SPIRE) - Credit: ESA/PACS & SPIRE Consortium/HOBYS Key Programme Consortia

The Rosette Nebula is located about 5,200 light years from Earth and is associated with a larger cloud that contains enough dust and gas to make the equivalent of 10,000 Sun-like stars. The Herschel image shows half of the nebula and most of the Rosette cloud. The massive stars powering the nebula lie to the right of the image but are invisible at these wavelengths. Each color represents a different temperature of dust, from –263ºC (only 10ºC above absolute zero) in the red emission to –233ºC in the blue.

The small spots near the center and in the redder regions of the image are lower mass protostars, similar in mass to the Sun. The bright smudges are dusty cocoons hiding massive protostars. These will eventually become stars containing around ten times the mass of the Sun and will significantly influence the formation of the next generation of stars.  The understanding of the formation of high-mass stars in our Galaxy is important because they feed so much light and other forms of energy into their parent cloud they can often trigger the formation of the next generation of stars.

Source: ESA

Filaments of cold dust stretching through our Galaxy

March 17, 2010 13:06 by scibuff

Giant filaments of cold dust stretching through our Galaxy are revealed in a new image from ESA’s Planck satellite. Analysing these structures could help to determine the forces that shape our Galaxy and trigger star formation.

Planck sees tapestry of cold dust

The image spans about 50° of the sky. It is a three-colour combination constructed from Planck’s two highest frequency channels (557 and 857 GHz, corresponding to wavelengths of 540 and 350 micrometres), and an image at the shorter wavelength of 100 micrometres made by the IRAS satellite. This combination visualises dust temperature very effectively: red corresponds to temperatures as cold as 10° above absolute zero, and white to those of a few tens of degrees. Overall, the image shows local dust structures within 500 light-years of the Sun - Credit: ESA/HFI Consortium/IRAS

The image shows the filamentary structure of dust in the solar neighborhood – within about 500 light-years of the Sun. The local filaments are connected to the Milky Way, which is the pink horizontal feature near the bottom of the image.

What makes these structures have these particular shapes is not well understood,” says Jan Tauber, ESA Project Scientist for Planck. The denser parts are called molecular clouds while the more diffuse parts are ‘cirrus’. They consist of both dust and gas, although the gas does not show up directly in this image.

There are many forces at work in the Galaxy to help shape the molecular clouds and cirrus into these filamentary patterns. For example, on large scales the Galaxy rotates, creating spiral patterns of stars, dust, and gas. Gravity exerts an important influence, pulling on the dust and gas. Radiation and particle jets from stars push the dust and gas around, and magnetic fields also play a role, although to what extent is presently unclear.

Bright spots in the image are dense clumps of matter where star formation may take place. As the clumps shrink, they become denser and better at shielding their interiors from light and other radiation. This allows them to cool more easily and collapse faster.

ESA’s Herschel space telescope can be used to study such regions in detail, but only Planck can find them all over the sky. Launched together in May 2009, Planck and Herschel are both studying the coolest components of the Universe. Planck looks at large structures, while Herschel can make detailed observations of smaller structures, such as nearby star-forming regions.

Source: ESA

For latest updates from the Herschel/Planck mission follow ESAHerschel and HerschelPlanck on twitter.

Herschel reveals unseen stellar nursery

December 16, 2009 15:16 by scibuff

Thanks to the superior sensitivity at the longest wavelength of infrared part of the electromagnetic spectrum, the Herschel Space Observatory unveiled a previously unseen stellar nursery, located within a dark could 1000 light years away in the constellation Aquila (the Eagle). No other infrared satellite could see the interior of this cloud through its dust shroud before.

A previously unseen stellar nursery in constellation Aquila - Credit: ESA and the SPIRE & PACS consortia, P. André (CEA Saclay) for the Gould’s Belt Key Programme Consortia

A previously unseen stellar nursery in constellation Aquila - Credit: ESA and the SPIRE & PACS consortia, P. André (CEA Saclay) for the Gould’s Belt Key Programme Consortia

The image (click here for high-resolution version) was taken on 24 October 2009 using two of Herschel’s instruments: the Photodetector Array Camera and Spectrometer (PACS) and the Spectral and Photometric Imaging Receiver (SPIRE). The two bright regions are areas where large newborn stars are causing hydrogen gas to shine.

Some 700 newly-forming stars are estimated to be crowded into these colourful filaments of dust. The complex is part of a mysterious ring of stars called Gould’s Belt. Embedded within the dusty filaments are 700 condensations of dust and gas that will eventually become stars. Astronomers estimate that about 100 are protostars, celestial objects in the final stages of formation. Each one just needs to ignite nuclear fusion in its core to become a true star. The other 600 objects are insufficiently developed to be considered protostars, but these too will eventually become another generation of stars.

This cloud is part of Gould’s Belt, a giant ring of stars that circles the night sky – the Solar System just happens to lie near the center of the belt. For more than a hundred years, astronomers have puzzled over the origin of this ring, which is tilted to the Milky Way by 20º. The first to notice this unexpected alignment, in the mid-19th century, was England’s John Herschel, the son of William, after whom ESA’s Herschel telescope is named. But it was Boston-born Benjamin Gould who brought the ring to wider attention in 1874.

Source: ESA