National Astronomy Meeting Press Release
8 July 2013
Super-Freezer Supernove 1987A is a dust factory RAS Press Release Author information
Surprisingly low temperatures detected in the remnant of the supernova 1987A
may explain the mystery of why space is so abundant with dust grains and
molecules. The results will be presented by Dr Mikako Matsuura at the
National Astronomy Meeting 2013 in St Andrews on Friday 5 July.
In 1987, an explosion of a massive star was detected in our neighbouring
galaxy, the Large Magellanic Cloud, just 170,000 light years away. This
supernova, dubbed 1987A, released approximately thousand million times more
energy than that emitted by the Sun in one year. Twenty five years later,
an international team of astronomers has used the Herschel Space Observatory
and Atacama Millimeter and Submillimeter Array (ALMA) to study the supernova
remnant. They found a vast reservoir of unexpectedly cold molecules and
"The powerful explosion we saw in 1987 scattered elements made by star into
space in the form of a very hot plasma. The gas has now cooled down to
temperatures between -250 to -170 degrees Celsius. That’s surprisingly
cold, comparable to the icy surface of Pluto at the edge of our Solar
System. The gas has formed molecules and some has even condensed into solid
grains of dust. The supernova has now become a super freezer!" said Dr
The Herschel observations show that the supernova produced dust and solid
material equal to about 250 000 times the mass of the Earth, or three
quarters of the mass of the Sun. To date, scientists have believed that
supernova remnants contain only very energetic atomic gas, detectable at
optical X-ray wavelengths; the new observations show that this is not the
case. The discovery of such a large mass of dust should help us to
understand how supernovae slowly spread and fill galaxies with gas, dust and
small rocky particles, some of which may eventually end up in the next
generation of stars and planets.
"We were surprised by the amount of dust and molecular gas in the reservoir
created by the supernova 1987A. The ALMA and Herschel observations show that
the reservoir contains carbon monoxide molecules equalling one tenth of the
mass of the Sun. Herschel shows that the dust mass was even larger - about
half the solar mass!" said Dr Matsuura.
"We don't get many opportunities to study supernova. These events are very
rare and the majority was found in very distant galaxies. Even with
relatively close ones, like 1987A, it’s difficult – although they are very
bright at the time of the explosion, the light from the supernovae fades
very quickly making it very difficult to observe them a few years after the
explosion," said Dr Matsuura. "Carl Sagan once said that: ‘We are all made
of star-stuff’. These results will help us understand how that material
The international team includes: Mikako Matsuura and M.J. Barlow of
University College London, Maarten Baes of Universiteit Gent, Eli Dwek of
NASA Goddard, Margaret Meixner of the Space Telescope Science Institute, J.
Kamenetzky and R. McCray of the University of Colorado at Boulder and
R. Indebetouw of the University of Virginia.
ALMA, an international astronomy facility, is a partnership of Europe, North
America and East Asia in cooperation with the Republic of Chile. ALMA
construction and operations are led on behalf of Europe by ESO, on behalf of
North America by the National Radio Astronomy Observatory (NRAO), and on
behalf of East Asia by the National Astronomical Observatory of Japan
(NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and
management of the construction, commissioning and operation of ALMA.
Herschel is an ESA space observatory with science instruments provided by
European-led Principal Investigator consortia and with important
participation from NASA.
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