Supernova Hunters Strike It Lucky
Much of astronomy is about being lucky – being in the right place at
the right time. This is exactly what happened recently for a group of
astronomers led by Alicia Soderberg of Princeton University.
On January 9th, 2008, using NASA’s Swift X-ray satellite,
they imaged a galaxy called NGC2770 which contained a slowly fading
supernova, known as SN 2007uy. Although this was a fairly routine
observation for the group to make, they discovered something special in
this particular image.
They spotted another supernova in the same galaxy which was as bright
as 100 billion Suns. This brightening of X-rays lasted around 4 minutes
and meant that the astronomers were aware of this new supernova,
SN2008D perhaps a month earlier than if they had only seen the
supernova’s glow in the optical waveband. By alerting colleagues, they
were able to point several ground-based telescopes (including the
Gemini North telescope on Mauna Kea, Hawaii) at the newly found
supernova.
SN2008D has been classed as a Type Ibc supernova, where a massive star
(around 10-20 times the mass of our Sun) collapses in on itself at the
end of its life. The resulting blast wave is emitted first in X-rays
and in the ultraviolet and then a few weeks later, the dying star
brightens dramatically in the optical.
Fellow researcher, Alex Filippenko said ‘As much energy is released in
one second by the death of a star as by all of the other stars you can
see in the visible Universe. Less than 1 percent of the stars in the
universe will die this way, in a supernova.’
NGC2770 is around 100 million light years away, in the constellation of
Lynx, and is a fairly regular spiral galaxy, apart from it experiencing
two supernovae in a matter of months !
Their work appears in the May 22 edition of the journal Nature.
NGC2770 has the co-ordinates
RA 09 09 33.79
Dec +33 07 25.2
which means that unfortunately, it isn’t visible to ground-based telescopes such as FT North until October.
