Young star fires off extremely rapid water molecules
A team including Leiden astronomers has observed water molecules moving away from a young, sun-like star at a speed of more than 200,000 km per hour. This is 80 times as fast as a bullet fired from an AK-47 weapon.
This observation - made with a HIFI molecule hunter on board the European space telescope Herschel (ESA) - came as a surprise to the astronomers: the water molecules would normally be destroyed in the shockwaves that accompany the birth of a star.
The observations have shown that water probably reforms into hot, dense clouds of gas as an effect of the shockwaves. The conditions are so favourable that every second, 100 million times the amount of water is formed that is contained in the Amazon river! The observations shed new light on the most energetic phase in the formation of a large mass (stars with a mass smaller than our sun). Our sun also experienced this process in the first stage of its evolution. Temperatures of more than 10,000 celsius are reached in this process. Water is one of the molecules that ensure that the temperature cools down quickly so that the young star can continue to grow.
'The quality of the HIFI data is so high that these jets of water stand out immediately. We are now studying how long the phase lasts in which the young star is so active,' explains Lars Kristensen, leader of the research project.
The star that was studied, L1448-MM, is located in the constellation of Perseus at a distance of some 750 light years. The HIFI space instrument was developed and constructed by a consortium of institutes and universities in Europe, Canada and the United States, led by SRON Netherlands Institute for Space Research. The data comes from the Water in Star Forming Regions with Herschel (WISH) Key Programme, that is headed by Professor Ewine van Dishoeck of the Leiden Sterrewacht.
The resultats of the research were presented on 30 May at the IAU Symposium 280 in Toledo, that was attended by some 450 astrochemists. An article on the research will appear shortly in Astronomy & Astrophysics.
Fundamentals of Science research profile area
(1 June 2011)