Most-delayed shuttle launch?

OM wrote:
On 29 Dec 2005 18:55:24 -0600, "William C. Keel"
wrote:

Well, actually professional astronomer. I only play a writer
on the stage, or something!

...Then as a professional astronomer, I've got a really good question
for you: considering its proximity as our closest known stellar
neighbor, what research has been done with regards to planetary
detection on the Centauri semi-Trinary? You'd think as close as it is,
the planet hunters would have been all over it in hopes of finding
something within a marginally reasonable distance.


There's nothing bright enough or massive enough to have jumped out
at people yet. There was a report of a possible object near Proxima
from Hubble data, but it was from an image reconstructed from a
set of 1-dimensional spectra and went away (might have been an internal
reflection from such a bright star, or a background star soon left
behind by Proxima's proper motion). HST was also used for a bunch of
images of Alpha A and B on the off chance that there was a Jupiter-like
planet at the right distance to show up - no such luck (the odds weren't
overwhelming to begind with; such a detection would take a good bit
of luck in the planet's location). There have been simulations of the
stability of planetary orbits in the binary system; something like
Earth would (a bit surprisingly) be stable around A for the age of our
solar system, although Jupiter's orbit wouldn't.

Likewise, nothing notable from radial-velocity changes (although
people are doing lots of observations trying to do asteroseismology
for comparison with the Sun).

Note from one of the OMWorld pages: I recently had occasion to interview
George Carruthers (for the same article). I just learned that the
backup camera from Apollo 16 was modfied and taken up on Skylab 4
for Kohoutek imaging. He was unaware that you can now buy an astronaut
action figure (Commander Wolf Perry) with a toy version of the
S201 camera from Apollo 16.

Bill Keel

In article ,
William C. Keel wrote:
Likewise, nothing notable from radial-velocity changes (although
people are doing lots of observations trying to do asteroseismology
for comparison with the Sun).

It's worth remembering that you need *years* of Doppler observations to
confirm the presence of an extrasolar planet in an Earthlike orbit, simply
because you need to observe at least a couple of orbits just to be sure
that the changes really are cyclic. Might be worse for Alpha Centauri,
because you'd also need to disentangle a planetary-orbit cycle from the
one caused by A.C. being a double star.

(Of course, for asteroseismology, you really want to observe from orbit.
Alas, MOST can't observe Alpha Centauri -- it can stare only at stars in a
belt centered slightly above the celestial equator, and Alpha Centauri is
too far from the equator for that. And the other asteroseismology
satellites are still on the ground, so far.) (MOST can also do planet
detection, by looking for the changes in a system's total brightness as
the planet goes through phases, but even for a star near the center of
MOST's viewing belt, the longest observing run it can do is about six
weeks, so the planet needs to be in a pretty close orbit around the star.)
--
spsystems.net is temporarily off the air; | Henry Spencer
mail to henry at zoo.utoronto.ca instead. |

"Henry Spencer" wrote in message
...
It's worth remembering that you need *years* of Doppler observations to
confirm the presence of an extrasolar planet in an Earthlike orbit, simply
because you need to observe at least a couple of orbits just to be sure
that the changes really are cyclic.

THat's my biggest problem with the current "Global Warming" hysteria- we've
only been collecting good data for a very short period of time, a few
hundred years at most for a very few places. We simply don't have enough
data to make any conclusion at all, much less blame people for the problem.

Is it real?
Is it a problem?
What causes it?

Those who have an agenda have decided the answers are yes, yes, and it's
people, dummy! We can't possibly have sufficient data to even answer the
first question for several more decades. After all, Europe went through a
"little Ice Age" that lasted a couple of hundred years. We can't even name
all the factors involved in making weather, much less assign blame for them.

Increasing temperatures would be a serious problem, but there's no data to
support the conclusions being made by those with social agendas. Because of
the possible consequences, better efforts- that is, more money- needs to be
spent on study. That's not likely to happen, of course, because it won't
bring results fast enough to suit those with agendas. No real scientist
would be placing the blame on people, unless they are prepared to provide
measurement data for thousands of places over the last thousand years,
because that's what would be needed to show any real world-wide trend, and
that data doesn't exist. It's not enough to show that temperatures are
rising to place the blame on people. How about solar flux readings for that
period? What about historical data for other areas that suffered long-term
climate changes?

Science takes too long for crusaders.