ESO Science Release | ALMA | 2015 Dec 16
New evidence for young planets in discs around young stars
[img3="Credit: ALMA (ESO/NAOJ/NRAO)/M. Kornmesser"]http://cdn.eso.org/images/screen/eso1549a.jpg[/img3][hr][/hr]Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have found the clearest indications yet that planets with masses several times that of Jupiter have recently formed in the discs of gas and dust around four young stars. Measurements of the gas around the stars also provide additional clues about the properties of those planets.
Planets are found around nearly every star, but astronomers still do not fully understand how — and under what conditions — they form. To answer such questions, they study the rotating discs of gas and dust present around young stars from which planets are built. But these discs are small and far from Earth, and the power of ALMA was needed for them to reveal their secrets.
A special class of discs, called transitional discs, have a surprising absence of dust in their centres, in the region around the star. Two main ideas have been put forward to explain these mysterious gaps. Firstly, the strong stellar winds and intense radiation could have blown away or destroyed the encircling material [1]. Alternatively, massive young planets in the process of formation could have cleared the material as they orbit the star [2].
The unparalleled sensitivity and image sharpness of ALMA have now allowed the team of astronomers, led by Nienke van der Marel from the Leiden Observatory in the Netherlands to map the distribution of gas and dust in four of these transitional discs better than ever before [3]. This in turn has allowed them to choose between the two options as the cause of the gaps for the first time. ...
Giant Planets Carving Paths around Four Young Stars
National Radio Astronomy Observatory | ALMA | 2015 Dec 16
Resolved gas cavities in transitional disks inferred from CO isotopologues with ALMA - Nienke van der Marel et al
- Astronomy & Astrophysics 585:A58 (Jan 2016) DOI: 10.1051/0004-6361/201526988
arXiv.org > astro-ph > arXiv:1511.07149 > 23 Nov 2015 (v1), 02 Dec 2015 (v2)
http://asterisk.apod.com/viewtopic.php?p=251436#p251436