Protoplanetary Disk tagged posts

This artist’s impression of the water snowline around the young star V883 Orionis, as detected with ALMA. Credit: A. Angelich (NRAO/AUI/NSF)/ALMA (ESO/NAOJ/NRAO)

A violent outburst by the young star V883 Orionis has given astronomers their first view of a water “snowline” in a protoplanetary disk – the transition point around the star where the temperature and pressure are low enough for water ice to form. An abrupt increase in the brightness of the star “flash heated” the inner portion of the disk, pushing the water snowline out much farther than normal, enabling astronomers to image it with ALMA. Under normal conditions, the water snowline would be much too close to the protostar to observe directly, even with ALMA’s remarkable resolution.

Typically, heat from a young Sun-like star preve...

ALMA image of the planet-forming disk around the young, Sun-like star TW Hydrae. The inset image (upper right) zooms in on the gap nearest to the star, which is at the same distance as the Earth is from the Sun, suggesting an infant version of our home planet could be emerging from the dust and gas. The additional concentric light and dark features represent other planet-forming regions farther out in the disk. Credit: S. Andrews (Harvard-Smithsonian CfA), ALMA (ESO/NAOJ/NRAO)

New images reveal never-before-seen details in the planet-forming disk around a nearby Sun-like star, including a tantalizing gap at the same distance from the star as the Earth is from the Sun. The disks of dust and gas that surround young stars are the formation sites of planets...

ALMA image of HL Tau at left; VLA image, showing clump of dust, at right. Credit: Carrasco-Gonzalez, et al.; Bill Saxton, NRAO/AUI/NSF

New images of a young star made with Very Large Array (VLA) reveal what scientists think may be the very earliest stages in the formation of planets, 450 light-years from Earth. A previous 2014 ALMA image showed gaps in the disk, presumably caused by planet-like bodies sweeping out the dust along their orbits. This image, showing in real life what theorists had proposed for years, was surprising, however, because the star, called HL Tau, is only about a million years old – very young by stellar standards.

The ALMA image showed details of the system in the outer portions of the disk, but in the inner portions of the disk, nearest to the young star, the thick...