For the first time, a team of astronomers has peered into the 'amniotic sac' of a planet-hosting star. In the research paper, the team described the surprising findings in their observations of the parent star, which is called HD 100546.
Lead author Ignacio Mendigutia, from the University of Leeds, said that 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. Mendigutia added that they have been able to detect for the first time the emission from the innermost part of the disk of gas that surrounds the central star, noting that unexpectedly, this emission is similar to that of 'barren' young stars that do not show any signs of active planet formation.
To observe this distant system, the astronomers used the Very Large Telescope Interferometer (VLTI), which is based in an observatory in Chile. The VLTI combines the observing power of four 8.2m-wide telescopes and can make images as sharp as that of a single telescope that is 130m in diameter.
Co-author Rene Oudmaijer concluded that with their observations of the inner disk of gas in the HD 100546 system, they are beginning to understand the earliest life of planet-hosting stars on a scale that is comparable to the Solar System. HD 100546 is a young star (only a thousandth of the age of the Sun) surrounded by a disk-shaped structure of gas and dust, called a 'proto-planetary disk', in which planets can form.
Such disks are common around young stars, but the one around HD 100546 is very peculiar: if the star were placed at the centre of our Solar System, the outer part of the disk would extend up to around ten times the orbit of Pluto. The study is published in the journal Monthly Notices of the Royal Astronomical Society