A fluffy disk around a baby star

Artist’s rendition of the "fluffy" layer associated with the protoplanetary disk of RY Tau, including jets coming from the star. 

Although typical young stars like RY Tau are often associated with jets, they are not visible in the HiCIAO observations at this time. 

Credit: NAOJ

An international team of astronomers that are members of the Strategic Exploration of Exoplanets and Disks with Subaru Telescope (SEEDS) Project has used Subaru Telescope's High Contrast Instrument for the Subaru Next Generation Adaptive Optics (HiCIAO) to observe a disk around the young star RY Tau (Tauri).

The team's analysis of the disk shows that a "fluffy" layer above it is responsible for the scattered light observed in the infrared image.

Detailed comparisons with computer simulations of scattered light from the disk reveal that this layer appears to be a remnant of material from an earlier phase of stellar and disk development, when dust and gas were falling onto the disk.

Since 2009, the five-year SEEDS Project has focused on direct imaging of exoplanets, i.e., planets orbiting stars outside of our Solar System, and disks around a targeted total of 500 stars.

Planet formation, an exciting and active area for astronomical research, has long fascinated many scientists.

Disks of dust and gas that rotate around young stars are of particular interest, because astronomers think that these are the sites where planets form—in these so-called "protoplanetary disks."

Since young stars and disks are born in molecular clouds, giant clouds of dust and gas, the role of dust becomes an important feature of understanding planet formation; it relates not only to the formation of rocky, Earth-like planets and the cores of giant Jupiter-like planets but also to that of moons, planetary rings, comets, and asteroids.

As a part of the SEEDS Project, the current team of researchers used HiCIAO mounted on the Subaru Telescope to observe a possible planet-forming disk around the young star RY Tau.

This star is about 460 light years away from Earth in the constellation Taurus and is around half a million years old.

The disk has a radius of about 70 AU (10 billion kilometers), which is a few times larger than the orbit of Neptune in our own Solar System.

More information: Takami, M. et al, 2013, High-Contrast Near-Infrared Imaging Polarimetry of the Protoplanetary Disk around RY Tau, Astrophysical Journal, Vol. 772, paper 145.