February 14, 2004
Extra Solar Planetary Transits

I've just read a very interesting paper by Steve Howell, "Photometric Search for Extra-Solar Planets".

He was nice enough to respond to my request for information about amateurs looking for transits:

As far as tranit observations, there are two kinds at present:

1) the ONE transiting planet HD209458 and

2) searching for transits around other stars, either those suspected to have planets (but not sure if transits occur) and a general search.

The first has been done by tons of people and the light curves are wonderful to obtain, I have observed a transit with an 8" Meade and ST8 CCD. The issue is are the data useful as well as fun. The answer is sort of but they are far too noisey for tests of theory or to try to pin down transit timings etc. You can look up HD209458 on the web and many places have an ephemeris you can use to calculate times of transit.

The second idea is to observe suspected stars with planets and see if a
transit occurs.

A few groups do this for every star listed as a possible planet candidate and
so far, no more have been found. A search all by yourself, is the final
choice. This is tough with most telescopes or any aperture as the number of
stars one has to search is nearly 1 million to find even a single candidate.

This promises to be a very interesting thread of thought... stay tuned.

Posted by Tom Munnecke at 06:01 PM
Paired Planetary Transits

It would seem to me that the search for interesting Extra Solar Planets would be those which would be able to see a transit of the earth or our solar system. That planet could have observed our transits, and have looked at our atmosphere, and possibly discovered our existence.


Having a "paired" relationship with such a planet could provide an interesting analysis... what if they have already discovered our transit, and are doing something from their planet to signal us? If so, what could that be? And if we discover a paired planet somewhere, what would our signal be?

Posted by Tom Munnecke at 05:56 PM