First science results from the MOST mission

The science team for the Microvariability and Oscillations of STars
mission (which we fondly refer to as Canada's "Humble" space telescope
:-) have announced their first science results:

- In the 1 July 2004 issue of Nature
(http://www.nature.com/cgi-taf/dynapa...995/index.html),
the MOST science team report a negative detection result, after
searching for p-mode (pressure-mode) oscillations in Procyon ("No
stellar p-mode oscillations in space-based photometry of Procyon,"
Matthews et al.; see
http://www.publicaffairs.ubc.ca/medi...mr-04-064.html for
UBC's p[ress release.) This is a surprising and controversial result,
since previous observers have reported detection of p-mode
oscillations in Procyon, based on spectroscopic observations (which
are sensitive to radial motion of the star's surface as it
oscillates). MOST makes photometric observations (which are sensitive
to changes in brightness at the star's surface as it oscillates), with
a sensitivity of roughly 1 part per million; based on existing theory
relating the expected relative amplitude of p-mode spectroscopic and
photometric signatures, the MOST team had expected to see a positive
detection result for Procyon. This negative result may call into
question the previous positive detection report, and if so may lead to
a re-thinking of how Procyon-like stars oscillate in response to
turbulent processes at their surface; however, there are other
possible explanations as well. Stay tuned, as the astronomers check
out what's behind this!

- At the Canadian Astronomical Society's CASCA 2004 conference on 15
June, (http://www3.physics.umanitoba.ca/CASCA/english/), MOST PI
Jaymie Matthews announced the detection using MOST data of p-mode
oscillations in eta Bootis (see
http://www.astro.ubc.ca/MOST/milestones/June2004_2.html for UBC's
press release), similar to p-mode oscillations seen in our Sun. This
is the first *photometric* detection of p-mode oscillations in any
star other than our Sun (a spectroscopic p-mode oscillation detection
for eta Boo had been reported earlier), which confirms that stellar
p-mode oscillations *can* be detected photometrically (which should
help in deciding what weight to give to the Procyon negative
detection).

- Kieran A. Carroll (once-upon-a-time MOST systems engineer/project
manager)
Dynacon (MOST prime contractor)