KELT-South is a small scientific telescope that is designed to detect transiting extrasolar planets.  The telescope is owned and operated by Vanderbilt University and was based on the design of KELT-North, which was conceived and designed at The Ohio State University Department of Astronomy.  KELT-North was deployed in late 2005 in Arizona, and has been operating since then.  That telescope has been gathering data for several years, and we are looking forward to its first discovered planets.  The KELT-South telescope will serve as a counterpart to it's Northern twin, surveying the Southern sky for transiting planets over the next few years.

What does KELT stand for?

KELT is an acronym for Kilodegree Extremely Little Telescope.  The word kilodegree refers to the fact that the telescope observes thousands of square degrees on the sky while it is operating, compared to typical modern telescopes which observe area tens of thousands of times smaller.  It is also extremely little compared to most other telescopes, since most scientific telescope these days have their apertures measured in meters, while ours has a 4.5cm aperture.  We take pride in getting great science out of such a small instrument!

What exactly is KELT-S?

KELT-S is a single telescope housed in its own building in South Africa.  It is not a "telescope" in the modern, commnonly pictured sense, since it does not have an optical tube.  It consists of a very high-quality digital camera mounted with a lens.  The camera/lens combination sits on a mount which points the camera at a desired place in the sky.  The camera/lens/mount assembly is what we refer to on this wiki as "the telescope".

What is it for?

The main purpose of KELT-S is to detect transiting extrasolar planets.  An extrasolar planet is a planet that orbits a star other than our sun, and is therefore not part of our solar system; they are also sometime called exoplanets.  A large number of extrasolar planets have been discovered so far (314 as of Sept 2008!).  For a full list of extrasolar planets with constant updates and a ton of other information, check out the Extrasolar Planets Encyclpedia.

A small fraction of exatrasolar planets orbit their stars so that the plane of their orbit is edge-on from our line of sight.  That means that once each time the planet orbits, is eclipses its star, an event we call a transit.  With sensitive instruments, we here on Earth can see that eclipse and use it to find out a huge amount about the planets and its star.  Because transiting extrasolar planets are so useful for science, we want to find as many as we can.  KELT-S is a tool we built to help us find these special planets.

How does it work?

In order to find extrasolar planets, KELT-S take pictures of large parts of the sky night after night, over many months and even years.  Each picture contains tens of thousands of stars, and after a long time, we have a record of the precise brightness of each of those stars.  We then examine the brightness of each star in our pictures to see if we can find a time where the light from the star dims by just the right amount for the right amount of time, then returns to its normal brightness.  If we're lucky, some of those cases will be the planet transiting its star, blocking the light and making it appear to get a little dimmer.  However, there are a number of other things that can cause a similar dimming of a star, so we have to carefully analyze and re-observe those stars with other telescopes to find out if we're really seeing a planet in action.

Stay tuned for answers to more questions, including:

Why doesn't KELT-S look like other telescopes?

Is anyone else doing this too?

What good is all of this?

If you have questions about KELT-S that aren't answered here, email us and we will try to post the answer on this page.