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
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.