The Telescope

n addition to taking detailed pictures of celestial objects, Hubble's versatile and efficient Space Telescope Imaging Spectrograph (STIS) acted like a prism to separate light from the cosmos into its component colors. This provided a wavelength "fingerprint" of the object being observed, which told us about its temperature, chemical composition, density, and motion. Spectrographic observations also reveal changes in celestial objects as the universe evolves. STIS spanned ultraviolet, visible, and near-infrared wavelengths. STIS stopped functioning in 2004 due to a power supply failure, and is currently in "safe mode" -- switched off but protected. It could be repaired during a future servicing mission.

The Great Black Hole Hunter

Astronomers were able to use STIS to hunt for black holes. The light emitted by stars and gas orbiting the center of a galaxy appears redder when moving away from us (redshift), and bluer when coming toward us (blueshift). STIS looked for redshifted material on one side of the suspected black hole and blueshifted material on the other, indicating that this material is orbiting an object at very high speeds.

STIS could sample 500 points along a celestial object simultaneously. This means that many regions in a planet's atmosphere or many stars within a galaxy could be recorded in one exposure, vastly improving Hubble's speed and efficiency.

STIS, which was built by Ball Aerospace, was installed in the Hubble Space Telescope during the 1997 Second Servicing Mission.

TOP