The Infrared Universe
In the 1980's, astronomers using IRAS data discovered about two dozen stars
which had infrared-emitting dust surrounding them, extending hundreds of
astronomical units from the stars. This discovery inspired astronomers
to make more detailed observations of these stars. What they found around
these stars were flat, disk-shaped, areas of dust in which planets have formed
or could be forming.
These findings have led the way to one of the most exciting
new areas of research in astronomy - the search for planets around other stars.
Among the stars studied were Beta Pictoris, HL Tauri, Vega, Epsilon Eridani
and Alpha Piscis Austrinus.
The discovery of these disks provided the first significant evidence
that other solar systems might exist.
Credit Left Image: J.-L. Beuzit et al. (Grenoble Obs.), ESO
Credit Right Image: G. Schneider (Steward Observatory, U. Arizona), B.Smith (U. Hawaii), NIC
The above left image is an
infrared image of Beta Pictoris taken at the European Southern Observatory
The presence of a warp in this disk indicates the existence of a Jupiter-sized
planet around this star. There is also evidence for the existence of comets
around Beta Pictoris.
With the exception of Beta Pictoris, these disks of material are not seen by
visible light telescopes.
The visible light from a planet or disk of material is hidden by the
brightness of the star that it orbits.
In the infrared, where planets have their peak brightness,
the brightness of the star is reduced, making it possible to detect a
planet in the infrared. To aid in the detection of planets, infrared
astronomers use occulting disks to mask out the light from a star allowing
for a better view of possible planets. The above right image is
an infrared view of a disk around the star HR 4796A taken with the
Hubble's NICMOS camera. In this image you can clearly see where the light
from the star (which is about 1000 times brighter than the disk) is blocked
so we can better see the ring of material around the star.
Exciting new infrared space missions such as the
Spitzer Space Telescope
and the future TPF
(The Terrestrial Planet Finder) as well as
ground-based missions such as the
Keck Interferometer will concentrate
their efforts on the discovery and study of extrasolar planets.
Infrared Universe Index |
Star Formation |
Extrasolar Planets |
Our Galaxy |
Other Galaxies |
Between the Stars |
Missing Mass - Brown Dwarfs? |
The Early Universe