Star Treks: the untold story (Forwarded)

Anglo-Australian Observatory
PO Box 296
Epping NSW 1710 Australia

Media assistance:
Helen Sim
+61-(0)2-9372-4251 (office)

Researcher contacts:

Dr Quentin Parker
Macquarie University and Anglo-Australian Observatory
(Head of RAVE Data Management Team)
+61-2-4800-4840 (AAO office, Sydney)
+61-2-9850-8910 (Macquarie University, Sydney)

Professor Fred Watson
Anglo-Australian Observatory
(RAVE Project Manager)
fgw @ aaocbn.aao.gov.au

Professor Joss Hawthorn
Anglo-Australian Observatory
(RAVE team member)
Currently at the Local Group Cosmology meeting at the Aspen Center for
Physics, Aspen, Colorado, USA.
Tel +1-(970)-925-2585

Professor Ken Freeman
Research School of Astronomy and Astrophysics, The Australian National
University
(RAVE Science Coordinator)
Currently holidaying in Western Australia
kcf @ mso.anu.edu.au

EMBARGOED until 0100 AEST 11 February 2006

Star Treks: the untold story

Some people are born, live and die in the one village. Others cross the
world to new homes. Stars do the same. Our Galaxy is a melting-pot of
stars from different places.

A team of Australian astronomers and their overseas colleagues have
today [Saturday 11 Feb. AEST] released data on 25 000 stars to the rest
of the astronomical community -- data that will help sort the travellers
from the stay-at-homes, and unravel the history of the Galaxy.

"Some stars were formed in our Galaxy. Others were originally in small
galaxies that have been swallowed by ours. By measuring their chemistry,
and tracing their speeds and directions, we can learn which stars came
from where," said Dr Quentin Parker of Macquarie University and the
Anglo-Australian Observatory, and head of the RAVE Data Management Team.

"It's like tracing how people have migrated all over the world, using
genetic markers."

The research program, called RAVE (Radial Velocity Experiment) has
collected the chemical compositions and velocities (speeds) of about 90
000 stars to date -- the 25 000 being released today and another 65 000
still being rigorously checked.

Even these first 25 000 measurements are more than all the stellar
velocities measured in the previous century.

Ultimately the astronomers plan to build a database of a million
individual stars.

To do this over just a few years they need to measure lots of stars
simultaneously. And for that they've turned to the Anglo-Australian
Observatory's 1.2-m UK Schmidt telescope at Siding Spring Observatory in
central New South Wales, Australia.

"The Schmidt is a really wide-eyed telescope. It can see a patch of sky
six degrees across -- that's like 12 full moons lined up in a row," said
Professor Fred Watson, RAVE Project Manager and Astronomer-in-Charge at
the Anglo-Australian Telescope.

The telescope is coupled with the AAO's 'six-degree field' (6dF)
spectrograph, which analyses the stars' light. The 6dF system can
capture the spectra of up to 150 stars simultaneously. From the spectra
the astronomers determine the stars' velocities, chemical composition,
temperature and gravitational strength.

The system can measure up to 700 stars a night.

The data release is being announced at the Local Group Cosmology meeting
in Aspen, Colorado, by the leader of the RAVE collaboration, Professor
Matthias Steinmetz of the Astrophysical Institute Potsdam in Germany.

The RAVE team comprises 55 researchers from 10 countries (Australia,
Canada, France, Germany, Italy, The Netherlands, Slovenia, Switzerland,
the UK and the USA).

Main RAVE webpage,
http://www.rave-survey.aip.de/rave/

Images and captions,
http://www.aao.gov.au/press/rave_data_release/