OSB archive
OSB archive

Neutrinos show Sun's dark side

Pete Wilton

If particles of dark matter are accumulating inside the Sun then we could use neutrinos to detect them.

A short article in this week’s Science, by Joseph Silk from Oxford University’s Department of Physics and Ilidio Lopes of the Instituto Superior Técnico, Portugal, suggests how this might be done.

They propose that the presence of dark matter in the Sun’s interior would cause a small but potentially significant drop in its central temperature. They calculate that in some scenarios an isothermal core – a region of constant temperature – should form, and this core could be picked up by neutrino detectors such as Canada’s Sudbury Neutrino Observatory [SNO].

“The existence of a dark matter isothermal core in the Sun would produce a unique signature written in the energies of solar neutrinos,” Joseph tells me.

“We calculate that the existence of dark matter in the Sun’s core could lead to a 4 per cent decrease in its central temperature and a 3 per cent increase in the central density of the Sun.”

Dark matter inside the Sun would decrease its central temperature by providing an additional way for redistributing the heat inside the solar core. The models developed by Joseph and Ilidio Lopes show that it should be possible to distinguish changes in the core produced by dark matter from those produced by other effects.

Professor Joseph Silk is based at Oxford University’s Department of Physics.