The white dwarf could blow up soon

Jan 5, 2010 06:50 GMT  ·  By
If it does not explode regularly, this white dwarf can accumulate enough mass from its companion to go supernova
   If it does not explode regularly, this white dwarf can accumulate enough mass from its companion to go supernova

Being the massive galaxy that it is, the Milky Way contains a little bit of everything. This includes highly explosive white dwarf stars that explode periodically at relatively stable intervals. Such a celestial body, which is long overdue for its next powerful eruption, lies closer to our planet than astronomers first estimated. According to experts, the Earth could be threatened by the effects of the massive supernova explosion, when it will finally take place millions of years from now, Space reports.

Recent investigations of the white dwarf, and also of its companion star have demonstrated that they lie only about 3,260 light-years away from our planet, which is a lot closer than anyone had originally estimated. The pair is located in the Compass Box, a Southern constellation also known as Pyxis. The system itself is known among astronomers as T Pyxidis. The new calculations were revealed in Washington DC yesterday, at the 215th meeting of the American Astronomical Society (AAS).

The thing about this white dwarf is that its next explosion into a supernova could release massive amounts of gamma radiation. These highly energetic photons have the ability to completely destroy the Earth's ozone layer, and also any other life form that may exist on the planet at the time of the explosion. The total energy output of the future supernova explosion will hit us with the equivalent of 1,000 solar flares, and all at the same time. One of the first side-effects that gamma-rays will produce will be the formation of massive amounts of nitrous oxide in our atmosphere, which, in essence, will completely halt the production of ozone.

According to Edward Sion, a Villanova University researcher and team member who worked on the study, we have nothing to fear at this point. Experts calculate that the white dwarf will blow up into a supernova in about ten million years. However, the researchers emphasize that this is a very short time frame at geological and astronomical scales. In addition, the white dwarf is known to be a relapsing nova, which means that it exhibits thermonuclear explosions once every 20 years or so. The last instances when such explosions were recorded took place in 1890, 1902, 1920, 1944 and 1967.

The team also mentioned that the star might, in fact, be larger than first thought. If this is verified by other investigations, then the white dwarf could already be on its path to reaching the Chandrasekhar Limit. This is the point where the core of a star collapses, and a large explosion ensues. This is known as a Type 1a supernova and is one of the most brutal events in the Universe. The energy released during these events is so massive that supernovae briefly outshine entire galaxies in the night sky. The time we have until the white dwarf reaches its Limit is directly related to the object's size, so we may be in for a surprise faster than ten million years.