Phil Fraering pgf@AUTO wrote in message ...
(Henry Spencer) writes:

Nobody knows what this means. Maybe the oscillations just aren't there.
Maybe they exist but are very short-lived, so they don't show up well.
Maybe the random noise in the brightness has different characteristics
than expected and it's swamping the oscillations. (Any of these means
that something is wrong with the Sun-based models used to predict the
observability of oscillations.) Maybe there is some subtle noise source
messing up the data (but what?).

Have they tried looking at other stars with apparent magnitudes comparable
to Procyon but known oscillations, to make sure the instrument is working
properly for objects of Procyon's brightness?

Yes, eta Bootis. See the UBC press release at
http://www.astro.ubc.ca/MOST/milestones/June2004_2.html for some
details. Eta Boo is a solar-type star, slightly more massive than, and
younger than, our Sun. Solar-type oscillations were detected. (Quick
phone call to the PI...) Yup, this is the first detection of p-mode
oscillations in a Solar-type star (other than the Sun) based on
photometric measurements; it tends to confirm an earlier report of
p-mode oscillations based on spectroscopic observations.

From http://www.astro.ubc.ca/MOST/targetstars.html, Procyon is
magnitude 0.38, and eta Boo is magnitude 2.68. Those are relative
magnitudes as seen from Earth, through a broad-band visible-light
filter. I don't know their absolute magnitudes off-hand, but Procyon
is of spectral class F5V, and eta Boo is G0IV; based on OBAFGKMN, they
must be close in size...

So, this tends to confirm that the instrument is working as intended.
Stay tuned for more investigation into what the heck is going on with
Procyon...

- Kieran A. Carroll
Dynacon