About Vulcan South

What is Vulcan South?

Vulcan South is an extension of the Vulcan Camera Project to the South Pole. Vulcan South is a project to search for extrasolar planets using an observatory based at the South Pole. When a planet passes in front of it's parent star, as seen from the Earth, it blocks a fraction of the light from the star. By monitoring the brightness of a large number of stars we can detect these events, known as transits. If the dimming is truly caused by a planet, it will be repeatable with a consistent period, duration, and brightness change. From the brightness change, the planet's size can be calculated. From the period, the size of the orbit can be calculated and the planet's temperature estimated. The Vulcan South photometer will be deployed to the South Pole in January 2004 with observations starting after sunset in April.

What kinds of planets can we find?

Vulcan South is designed to look for giant Jupiter-sized planets that are orbiting very close to their stars. The planets we hope to see have orbital periods from 1 to 7 days. Surprisingly, many of these close-in giant planets are known to exist. The Extrasolar Planets Encyclopaedia contains an up-to-date list of the known extrasolar planets and is a great starting point for extrasolar planet information.

The search for Earth-like planets is best carried out from space, where the Earth's atmosphere and day/night cycle don't interfere. The Kepler Mission is currently being developed for just such a search.

Why the South Pole?

The South Pole offers several advantages for a transit search project. The main advantage is the long winter night, which allows us to observe stars continuously for several months. At a temperate latitude site the Sun keeps us from seeing 1/2 to 2/3 of all transits, since it is daylight much of the time. At the the South Pole we can detect periodic transits up to 3 times faster than the California-based Vulcan project.

The South Pole offers a unique land location where the stars never rise or set, minimizing the brightness change as we observe them through different amounts of atmosphere. The cold stable atmosphere also minimizes the changes in brightness that occur as the stars twinkle, known as scintillation noise. Both of these noise sources hinder precise brightness measurements.