RAVE survey ventures beyond our immediate home

A team of astronomers led by Maarten Breddels from the Kapteyn Astronomical Institute from the University of Groningen has determined the distances to tens of thousands of nearby stars in the RAVE (Radial velocity experiment) dataset, a survey that will eventually provide spectra for 1 million stars in the Milky Way. The public release of this catalogue, which also contains velocities for all stars, will allow astronomers across the globe to determine the local dynamics of our Galaxy.

It has been nearly twelve years since the European satellite HIPPARCOS released a catalogue containing the motions projected on the sky of stars in our immediate neighbourhood. Nearly six years later, the most complete view of our immediate neighbourhood and of its motion was obtained when the HIPPARCOS dataset was supplemented with velocities along the line-of-sight. Now, the RAVE survey (and thanks to the legacy of HIPPARCOS/TYCHO and other ground-based datasets) releases a new catalogue with full kinematical information for a much larger volume. While it is relatively easy to measure the location of a star on the sky, determining how far it is from us requires significant observational and modeling efforts. Only with this information is it possible to establish how fast stars move, and hence how much mass there is in the Galaxy for example.

The multi-dimensional stellar map we had thus far was largely restricted to our immediate neighbourhood, say one block from our home, the Solar System.  The map we have been able to construct with RAVE allows us to venture into the "city lights", roughly 10 to 20 blocks from home. As a young child we get to know the world by first exploring our home and the neighbours. As we grow older, we begin to explore the city, discover its lay-out, the dynamics, where cars travel fast or slow, the various neighbourhoods and where our own fits in. This is exactly what RAVE is allowing us to do, but on a much larger scale, that of our own Galaxy.

The article describing this work has been accepted for publication in Astronomy & Astrophysics. The catalogue containing full 6D phase-space information for 20,000 stars can be downloaded from http://www.astro.rug.nl/~rave and will be extended as the RAVE survey publishes future data releases.  More information, including a pre-print of the article and visualization material can be found in the same website.

The RAVE team is using the "six-degree field" multi-object spectrograph on the 1.2-m UK Schmidt Telescope at the Anglo-Australian Observatory, located at Siding Spring Observatory in New South Wales, Australia. RAVE (www.rave-survey.aip.de) includes members from Australia, Canada, France, Germany, Italy, The Netherlands, Slovenia, the United Kingdom and the United States.

Contact information

Maarten Breddels, Kapteyn Astronomical Institute, University of Groningen
Tel:  +31 (0)50 363 4080
E-mail

Prof. Dr. Amina Helmi, Kapteyn Astronomical Institute, University of Groningen
Tel: +31 (0)50 363 4045
E-mail