Researchers on board NASA’s Stratospheric Observatory for Infrared
Astronomy, SOFIA, observed the collapse of portions of six interstellar
clouds on their way to becoming new stars that will be much larger than
our sun.
When a gas cloud collapses on itself, the cloud’s own gravity causes
it to contract and the contraction produces heat friction. Heat from the
contraction eventually causes the core to ignite hydrogen fusion
reactions creating a star.
Astronomers are excited about this SOFIA research because there have
been very few previous direct observations of collapse motion. These
SOFIA observations have enabled scientists to confirm theoretical models
about how interstellar clouds collapse to become stars and the pace at
which they collapse. Actually observing this collapse, called “infall,”
is extremely challenging because it happens relatively quickly in
astronomical terms.
“Detecting infall in protostars is very difficult to observe, but is
critical to confirm our overall understanding of star formation,” said
Universities Space Research Association’s Erick Young, SOFIA Science
Mission Operations director.
Using the observatory’s GREAT instrument, the German Receiver for
Astronomy at Terahertz Frequencies, scientists searched for this
developmental stage in nine embryonic stars, called protostars, by
measuring the motions of the material within them. They found that six
of the nine protostars were actively collapsing, adding substantially to
the previous list of less than a dozen protostars directly determined
to be in this infall stage.
For several weeks each year, the SOFIA team operates from
Christchurch, New Zealand, to study objects best observed from southern
latitudes, including the complete center of the Milky Way where many
star-forming regions are located. Heading south during the Southern
Hemisphere’s winter months, when the nights are long and
infrared-blocking water vapor is especially low, also creates prime
observing conditions.
“With the Southern Hemisphere deployments of SOFIA, the full inner
Milky Way comes into reach for star formation studies. This is crucial
for observations of the earliest phases of high-mass star formation,
since this is a relatively rapid and rare event,” said Friedrich
Wyrowski, astronomer at the Max-Planck Institute for Radio Astronomy in
Bonn, Germany.
The results were from observations made in the Southern Hemisphere in 2015, and were published in Astronomy and Astrophysics
earlier this year. SOFIA spent seven weeks during 2016 observing from
Christchurch. The scientific teams involved in the Southern Hemisphere
observations are analyzing the acquired data now.
SOFIA is a Boeing 747SP jetliner modified to carry a 100-inch
diameter telescope. It is a joint project of NASA and the German
Aerospace Center, DLR. NASA’s Ames Research Center in California’s
Silicon Valley manages the SOFIA program, science and mission operations
in cooperation with the Universities Space Research Association
headquartered in Columbia, Maryland, and the German SOFIA Institute
(DSI) at the University of Stuttgart. The aircraft is based at NASA’s
Armstrong Flight Research Center's Hangar 703, in Palmdale, California.
Point of Contact
Nicholas A. Veronico
Email: NVeronico@sofia.usra.edu
SOFIA Science Center NASA Ames Research Center, Moffett Field, California
Nicholas A. Veronico
Email: NVeronico@sofia.usra.edu
SOFIA Science Center NASA Ames Research Center, Moffett Field, California
Editor: Kassandra Bell
Source: NASA/SOFIA
