TASS sees a planet

["Gutzwiller, Michael" <mgutzwiller@lanvision.com>]

Last night the weather cooperated and I was able to take good data for
the predicted transit of the hot Jupiter orbiting HD209458.

The night was essentially photometric with little variation in the zero
point adjustment (one sigma of 0.009 magnitudes)

Preliminary plots in both V and I are available at

http://home.fuse.net/deepsky/209458.jpg

The error bars are at +-0.008 magnitudes (2 sigma).

I just barely caught the egress event, it may have happened a littler
earlier than predicted or my program may not have positioned the camera on
the field as soon as it should have.  I'll investigate that later.  The
numbers on the x axis are file numbers from the beginning of the night.
Each exposure was 90 seconds with theoretical errors of about 0.004
magnitudes in both V and I.  Each exposure was about 2.5 minutes apart.

The magnitudes were calculated by a newer version of the Star program.
There may be some room for improvement in the numbers though the
measurements are essentially a version of ensemble photometry.


Mike G.