(See descriiption below)
Protoplanetary Disk of Star HL Tauri
have captured the best image ever of planet formation around an infant
star as part of the testing and verification process for the Atacama
Large Millimeter/submillimeter Array’s (ALMA) new high-resolution
This revolutionary new image reveals in
astonishing detail the planet-forming disk surrounding HL Tau, a
Sun-like star located approximately 450 light-years from Earth in the
constellation Taurus. The diameter of the disk is about 25
ALMA uncovered never-before-seen features in this
system, including multiple concentric rings separated by clearly
defined gaps. These structures suggest that planet formation is already
well underway around this remarkably young star.
are almost certainly the result of young planet-like bodies that are
being formed in the disk. This is surprising since HL Tau is no more
than a million years old and such young stars are not expected to have
large planetary bodies capable of producing the structures we see in
this image," said ALMA Deputy Director Stuartt Corder.
stars are believed to form within clouds of gas and dust that collapse
under gravity. Over time, the surrounding dust particles stick
together, growing into sand, pebbles, and larger-size rocks, which
eventually settle into a thin protoplanetary disk where asteroids,
comets, and planets form. Once these planetary bodies acquire enough
mass, they dramatically reshape the structure of their natal disk,
fashioning rings and gaps as the planets sweep their orbits clear of
debris and shepherd dust and gas into tighter and more confined zones.
Star HL Tauri has a jet named HH 151 emitting at right angles to the disk.