C
Gas from evaporating comets found around
young star
arbon monoxide gas has been spotted streaming away from a young star, implying that icy
comets are being vaporised in an asteroid belt encircling it. e carbon monoxide was spotted by an international team of researchers led by astronomers at the
University of Cambridge, who used the Atacama Large Millimeter/submillimeter Array (ALMA) in
Chile to observe the young star NO Lup, which is 400 light years away in the constellation of
Lupus, the Hare. e star is surrounded by a cold debris disc of rock and dust, made from material
left over from smash-ups between protoplanets during the planet-building phase.
ALMA saw the signature of carbon monoxide racing away from the disc at 22 kilometres per second
- fast enough to escape the gravity of the star system.
“Given how far away the gas was from the star, it was moving much faster than expected,” says
Joshua Lovell of the University of Cambridge. “ is had us puzzled for quite some time.”
It seems that something is causing volatile materials such as water, carbon dioxide and the observed
carbon monoxide to sublimate from the material in the disc. Although the mechanism behind this
remains a mystery, there is some evidence that a similar event took place in the history of our Solar
System. When NASA’s New Horizons spacecraft visited the Kuiper belt object known as Ultima
ule on 1 January 2019, it also found evidence that gases had sublimated away, 4.5 billion years
ago. e events taking place around NO Lup could therefore be a short-lived occurrence that sheds
light on our own Solar System’s early history.
e ndings are to be published in the Monthly Notices of the Royal Astronomical Society.
An artist’s impression of carbon monoxide gas streaming away from a dust disc encircling the young star NO Lup.
ViewGas from evaporating comets fo...
January 2021
Astronomy Now