Dutch researchers in an international team of astronomers have discovered a star which will explode in the near future. The star is located in the constellation Cassiopeia. The researchers have published their findings in the February 2003 issue of the Astrophysical Journal.
An international team of astronomers studied the star Rho Cassiopeiae from 1993 to 2002. They did this using a spectrograph developed in Utrecht. To everyone’s surprise the star suddenly cooled from 7000oC to 4000oC in the year 2000. With this the star shot ejecta into space, which weighed ten thousand times the mass of earth. This is the largest eruption astronomers have ever seen in a single outburst of a cool hypergiant star.
According to the researchers the star could completely explode at any moment. Such an event has never previously been observed, which is why the researchers are continuing with their observations. However, the star probably exploded a long time ago; the light reaching us now has already been travelling for ten thousand years.
Rho Cassiopeiae is one of the brightest yellow hypergiants in the Milky Way. The star is about 10,000 light years away from Earth (the Sun is a few light minutes way) and is visible to the naked eye because it is half a million times brighter than the Sun.
The researchers used the William Herschel Telescope, which is one of the Isaac Newton Group of Telescopes (ING). The ING is a cooperative venture between The Netherlands Organisation for Scientific Research, the British Particle Physics and Astronomy Research Council and the Spanish Instituto de Astrofísica de Canarias. The group owns three telescopes: the 4.2 metre William Herschel Telescope, the 2.5 metre Isaac Newton Telescope and the 1.0 metre Jacobus Kapteyn Telescope. The telescopes are located on La Palma in the Roque de Los Muchachos Observatory.
