7
May 10

Herschel's HIFI follows the trail of cosmic water

Source: ESA Science and Technology

Water is an extremely important molecule in the Universe, abundant in a large variety of cosmic environments — from our own blue planet and its neighbourhood, the Solar System, through interstellar clouds where new stars and planets are formed, and even beyond the Milky Way, in star-forming galaxies. Due to the large amount of water vapour present in the Earth's atmosphere, however, astronomical observations of water from ground-based facilities are virtually impossible, even from the driest and highest deserts; they need to be carried out with space observatories.

Herschel's HIFI instrument was especially designed to follow the water trail in the Universe over a wide range of scales, from the Solar System out to extragalactic sources. Early results, presented this week at the Herschel First Results Symposium, demonstrate how HIFI uses water to probe the physical and chemical conditions in different regions of the cosmos.(read more)

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7
May 10

Herschel unveils rare massive stars in the act of forming

Source: ESA Science and Technology


RCW 120 as seen by Herschel.
Credit: ESA, PACS & SPIRE Consortia, A. Zavagno

Massive stars are the rare birds of astrophysics. With a mass over eight times that of the Sun, these stars are much less common than their lower-mass counterparts. In addition, they are short-lived, consuming their nuclear fuel at a rapid rate before ending their life in spectacular manner as a supernova. Their scarcity means that observations of these rare giants can prove difficult to obtain, but characterising these elusive objects is essential for understanding the chemical and dynamical evolution of galaxies.

The mechanism leading to the formation of massive stars is still largely debated. Detecting these objects in their earliest phases is a highly challenging task, since they are embedded in dusty cocoons that hide them from view. However, the dust that absorbs their light re-emits it at infrared wavelengths, making an infrared observatory such as Herschel a unique tool for locating newborn massive stars in their natal nests.

New images from ESA's Herschel space observatory reveal high-mass protostars around two ionised regions in our Galaxy. The detection of these rare stars in an early phase of evolution is key to understanding the mysterious formation of massive stars.(read more)

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