ALMA reveals an enigmatic gas clump around a young star


Astronomers using the Atacama Large Millimeter Array (ALMA) telescope in northern Chile have announced the discovery of an unexpected clump of carbon monoxide gas in the dusty disc around Beta Pictoris star. The strange thing is that such gas is expected to be rapidly broken by the central star’s light. Therefore, something — probably frequent collisions between small, icy bodies such as comets — must be causing the gas to be continuously replenished.

New observations from ALMA now show that the disc is permeated by carbon monoxide gas (white damp). Paradoxically, the presence of the carbon monoxide, which is so harmful to humans on Earth, indicates that the Beta Pictoris planetary system may eventually become a good habitat for life. The cometary bombardment that its planets are currently undergoing is likely to provide them with life-enabling water.

But there was another surprise in the ALMA observations, which did not just discover the carbon monoxide, but also mapped its location in the disc through ALMA’s unique ability to simultaneously measure both position and velocity: the gas is concentrated in a single compact clump. This concentration lies 13 billion kilometers from the star, which is about three times the distance of Neptune from the Sun. The nature of this clump is still a mystery.

In both cases astronomers have reasons to be optimistic that there are several more planets waiting to be found around Beta Pictoris.

Further observations are planned with ALMA, which is still ramping up to its full capabilities, to shed more light on this intriguing planetary system, and so help us to understand what the conditions were like during the formation of the Solar System.