Media Release |
Jun. 30, 2004
CANADA’S FIRST SPACE TELESCOPE FINDS STELLAR “FLAT
LINER”
DISCOVERY OVERTURNS 20 YEARS OF PREVIOUS RESEARCH
MOST, Canada’s first space telescope, celebrates its
first birthday today, but its latest surprising results could
spoil the party for other astronomers whose earlier results
are now being questioned.
The MOST team used their tiny but powerful satellite as a
stellar stethoscope to take the pulse of one of the best-known
stars in the Galaxy, called Procyon (PRO-see-yon), and were
shocked to discover their cosmic patient is a “flat
liner”. The star shows none of the pulsations predicted
by over 20 years of earlier theory and observations from Earth.
The journal Nature will publish these unexpected findings
on July 1.
“The lack of a pulse doesn't mean the star Procyon
is dead,” explained MOST Mission Scientist Dr. Jaymie
Matthews of the University of British Columbia. “But
it does mean that some of our long-held theories about stars
like this need to be put on the critical list. And that future
space missions following in the path of MOST will have to
revise their target lists and observing strategies in light
of this null result.”
MOST, which stands for Microvariability and Oscillations
of STars, is a Canadian Space Agency mission. UBC is the main
contractor for the instrument and scientific operations of
the MOST mission.
MOST is not much bigger than a suitcase but is able to measure
the brightness variations of stars more precisely than any
other instrument on Earth or in space. It was launched one
year ago on June 30, aboard a modified Russian nuclear missile.
To mark the occasion, MOST scientists celebrated with a birthday
party complete with cake and dehydrated “space”
ice cream.
“MOST is only one year old, but it’s proving to
be a very precocious child,” said Roger Colley, a senior
official from the Canadian Space Agency. “In its first
six months of operation, MOST has already given us new perspectives
on the stars we thought we knew best, the ones in our own
Galactic backyard. In that way, it’s providing new insights
into the Sun, the star we need to understand better to predict
the future of our home planet.”
To interview Jaymie Matthews, please call him directly
at (w) 604.822.2696 or (h) 604.734.7602
Backgrounder
MOST and Procyon: Much ado about nothing –literally
The MOST Canadian space telescope was launched from northern
Russia, in June 2003, aboard a former Soviet ICBM (Intercontinental
Ballistic Missile) converted to peaceful use. Weighing only
54 kg, this suitcase-sized microsatellite is packed with a
small telescope and electronic camera to study stellar variability.
Its first prime target was Procyon, the eighth brightest star
in the night sky, similar to the Sun but more massive and
further along in life. Astronomers had concluded that Procyon
was the best candidate for the new technique of “asteroseismology”
– using surface vibrations to probe the inside of a
star, similar to how geophysicists use earthquake vibrations
to probe the Earth's core.
MOST monitored Procyon up to eight times per minute for 32
days, with lapses totalling only seven hours over that entire
time. Accumulating about 250,000 individual measurements,
MOST reached a level of light-measuring precision at least
10 times better than the best ever achieved before from Earth
or space. The MOST team was surprised to find that Procyon
was not vibrating, and soon showed that a more careful treatment
of stellar models indicated that it should indeed be stable.
The lack of waves detected on the surface of Procyon has ironically
generated waves in the worldwide community of stellar astronomers.
These results contradict theories and observational evidence
that had mounted over the last 20 years. Several planned international
space missions have been designed based on the firm belief
that stars like Procyon pulsate. The MOST findings mean target
lists and observing strategies for these satellites may have
to be seriously revamped.
Future targets for MOST include other stars representing the
Sun at various stages in its life, and stars known to have
giant planets. MOST is designed to be able to register the
tiny changes in brightness that will occur as a planet orbits
its parent star. The way in which the light changes will tell
astronomers about the atmospheric composition of these mysterious
worlds, and even if they have clouds.
“It’s like doing a weather report for a planet
outside our Solar System,” says Dr. Jaymie Matthews,
MOST Mission Scientist, of the University of British Columbia.
MOST (Microvariability & Oscillations of STars) is a Canadian
Space Agency mission. UBC is the main contractor for the instrument
and scientific operations of the MOST mission.
Dynacon Inc. of Mississauga, Ontario, is the prime contractor
for the satellite and its operation, with the University of
Toronto Institute for Aerospace Studies (UTIAS) as a major
subcontractor.
MOST is tracked and operated through a global network of
ground stations located at UTIAS, UBC and the University of
Vienna.
Other partners include the Harvard-Smithsonian Center for
Astrophysics, Université de Montréal, and St.
Mary’s University in Halifax.
For more information on MOST, visit: www.astro.ubc.ca/MOST/
For more information on the Canadian Space Agency, visit:
www.space.gc.ca/asc/eng/default.asp
For more information on Dyancon, visit: www.dynacon.ca
For more information on UTIAS, visit: www.utias-sfl.net
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