YOUNG STARS SCULPT GAS WITH POWERFUL OUTFLOWS
A dramatic structure of arched, ragged filaments
decorates this Hubble Space Telescope view of one
of the most dynamic and intricately detailed star-forming
regions in space. A ridge of material gently cradles
a star cluster in its center. The cluster, known
as NGC 346 is located 210,000 light-years away in
the Small Magellanic Cloud (SMC), a satellite galaxy
of our Milky Way.
A torrent of radiation from the cluster's hot stars
eats into denser areas creating a fantasy sculpture
of dust and gas. The dark, intricately beaded edge
of the ridge, seen in silhouette by Hubble, is particularly
dramatic. It contains several small dust globules
that point back towards the central cluster, like
windsocks caught in a gale.
Energetic outflows and radiation from hot young
stars are eroding the dense outer portions of the
star-forming region, formally known as N66, exposing
new stellar nurseries. The diffuse fringes of the
nebula prevent the energetic outflows from streaming
directly away from the cluster, leaving instead
a trail of filaments marking the swirling path of
the outflows.
The NGC 346 cluster, at the center of this Hubble
image, is resolved into at least three sub-clusters
and collectively contains dozens of hot, high-mass
stars, more than half of the known high-mass stars
in the entire SMC galaxy. A myriad of smaller, compact
clusters is also visible throughout the region.
Some of these mini-clusters appear to be embedded
in dust and nebulosity, and are sites of recent
or ongoing star formation. Much of the starlight
from these clusters is muted by local dust concentrations
that are the remnants of the original molecular
cloud that collapsed to form N66. This image of
NGC 346 and its surrounding star formation region
was taken with Hubble's Advanced Camera for Surveys
in July 2004. The image appears in black and white
to show the dramatic structure of this pure Hubble
filter - Halpha (pronounced H alpha) -
which constrains light that is only emitted from
doubly ionized hydrogen. In star forming regions,
this filter is particularly useful in showing detail
and structure from gas and dust.
See color images
of NGC 346 and its environment.
Credit: NASA, ESA, and The Hubble Heritage Team
(STScI/AURA)
Acknowledgment: A. Nota (STScI/ESA) |
