Artist’s impression of the HD 100546 system, containing a planet that is forming that could be boosting a transfer of material from the gas-rich outer part of the disc to the inner regions. Image Credit: David Cabezas Jimeno (SEA)
A team of astronomers have announced their discovery of a star that is still forming, giving unprecedented insight into a growing planetary system for the first time.
Parent star HD 100546 is just 325 lightyears away and was observed using the Very Large Telescope Interferometer (VLTI) in Chile.
Its discovery gave the team the opportunity to detect emission from the innermost part of the star’s gas disc for the first time.
Lead author Dr Ignacio Mendigutía from the School of Physics and Astronomy at the University of Leeds says:
“Nobody has ever been able to probe this close to a star that is still forming and which also has at least one planet so close in.”
HD 100546 is one thousandth of the age of our own Sun.
Its proto-planetary disc, in which planets will theoretically eventually form, is so big that if placed in the middle of our Solar System, its outer part would extend up to about ten times the orbit of Pluto.
“More interestingly, the disc exhibits a gap that is devoid of material,” Mendigutía says.
“This gap is very large, about 10 times the size of the space that separates the Sun from Earth.
The inner disc of gas could only survive for a few years before being trapped by the central star, so it must be continuously replenished somehow.
“We suggest that the gravitational influence of the still-forming planet – or possibly planets – in the gap could be boosting a transfer of material from the gas-rich outer part of the disc to the inner regions.”
Systems like this that have both a planet and a gap in the protoplanetary disc are rare, giving the team that discovered HD 100546 the opportunity for a unique insight into the early stages of planetary system development.