in Cambridge, Massachusetts, the Smithsonian Astrophysical
Observatory (SAO) is joined with the Harvard College
Observatory to form the Harvard-Smithsonian Center
for Astrophysics (CfA), where more than 300 scientists
are engaged in a broad program of research in astronomy,
astrophysics, Earth and space sciences, and science
education. The Smithsonian Institution also continued
to support national aerospace activities through research
and education activities at the National Air and Space
Museum in Washington, D.C.
halfway across the universe to analyze light from exploded
stars that died long ago, SAO astronomers and their Harvard
colleagues have inferred that the cosmos will expand forever.
Using the Hubble Space Telescope, these scientists have
found that there is too little matter in the universe to
halt its expansion. As a result, the universe should continue
to balloon outward infinitely.
of astronomers, including scientists at SAO, discovered
a disk of gas and dust around a nearby star that may be
formingor may have already formedplanets. The
protoplanetary disk, about three times the diameter of Pluto's
orbit around the Sun, surrounds a star roughly 220 light-years
from Earth. The discovery was made with a NASA-funded instrument
on a telescope in Chile at about the same time as an independent
discovery was made by a second team using NASA's Infrared
Telescope Facility in Hawaii.
from the CfA and the University of Arizona used the Hubble
Space Telescope to study approximately two dozen examples
of "gravitational lensing" in a project dubbed "CASTLeS"
(which stands for the CfA-Arizona Space Telescope Lens Survey).
Gravitational lensing is a phenomenon predicted by Einstein's
Theory of General Relativity in which light rays emanating
from a distant background object (such as a quasar) are
bent by the gravitational field of a foreground object (such
as a massive black hole or galaxy), thus distorting the
appearance of the background object. The results will be
used to learn more about the properties of distant galaxies
and to determine the Hubble Constantthat is, the rate
at which the universe is expanding. To illustrate gravitational
lensing in a more familiar setting, the team started with
a digitized photograph of the Smithsonian's Castle and then
used computer software originally written for analyzing
astronomical gravitational lenses to distort the image as
if a black hole with the mass of the planet Saturn lay between
the viewer and the Castle.