A Few Representative Projects
An Extrasolar Planet Search
We search for PLANETS near Proxima Centauri and Barnard's Star by detecting
wiggles in their motion. Why would Proxima Cen wiggle? It and any associated
planet would orbit a common center of mass. No, we have not found any planets,
yet. Here
is some information about Proxima Centauri and a
status report on our search.
Often in astronomy one looks for one thing and finds another. The FGS are
also very good photometers. Proxima Centauri turned out to be a periodic
variable star. The announcement paper was based
on less than half the data sets we have now. The period may have changed
to 82 days from the originally announced 41 days. Finally, here is an example
of the periodograms
which we use in our search. The only frequency for which there is any power
in both x and y is near 0.013 /day. We remain skeptical that it is an astronomical
effect.
Hatzes, Kuerster, and Cochran are obtaining high precision (+/- 100 m/s)
radial velocity measures of Proxima Cen from ESO. We should know if the
planet exists or not by comparing periodicities seen in the astrometry with
any found in the radial velocity results. So far, the eight epochs obtained
over 2 years are not inconsistent with a variation with a period near 90
days. More data are required to rule out noise as the producer of this variation.
Here is some information about Barnard's
Star . We are in the middle of our series of observations of this
object. They will continue through 1995-6 (Cycle 5). Thus far, neither astrometric
nor radial velocity measurements have yielded a planet.
Cleaning Up the Hyades Color-Magnitude Diagram
Here is a color picture of a typical
star cluster (M35). The color-magnitude
(or Hertzsprung-Russell) diagram shows the main-sequence to have width.
Some of this width is due to unresolved binary stars. We are inspecting
many members of the Hyades star cluster in an effort to tighten up the HR
diagram. The Hyades are a cornerstone of the cosmic distance scale.
The Parallax of delta Cephei
Jupiter Relativity Experiment
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