Titlebook: Hubble Revisited; New Images from the Daniel Fischer,Hilmar Duerbeck Book 1998 Springer-Verlag New York, Inc. 1998 Gravitation.Hubble Deep

小卷發(fā)

The First Servicing Missionbservation of pulsating stars in other galaxies — one of the key projects of the Hubble Space Telescope (and, much earlier, of its namesake, Edwin P. Hubble) — had to be postponed. Determining a more precise distance scale for the universe would have to wait.

Digitalis

A View into the Depths of Space and Time: The Hubble Deep Fieldvents occur or the opportunity for unique observations arises. At the end of 1995, Hubble’s discretionary time was used to observe one small area in the sky for 10 days. The main characteristic of the target area was that it contained “nothing” — no star, quasar, or conspicuous radio or infrared source.

情愛

The Search for Cosmic Numbers. is the Hubble constant, the measure for the rate at which the universe expands. The determination of this number is theoretically very simple. The redshift is plotted against the distance for a number of galaxies; this plot will show a linear relationship (the Hubble law), and the slope of that line gives the value for the Hubble constant.

Leaven

Gravitational Lenses: Hubble’s Telephoto Lensnobody believed that such “minimal” effects could ever be observed in the universe. What would happen if the gravitational lens were caused not by a star but by a massive galaxy or even a cluster of galaxies? This should enhance the effect considerably. Several decades passed before the first cases of gravitational lenses were observed.

inveigh

遠(yuǎn)足

The Second Servicing Missionw and better detectors. After all, the scientific instruments used for Hubble had been developed more than 10 years previously and were no longer quite state of the art. Work on the second-generation instruments had already started when Hubble was launched, and the new instruments would contain the technology of the early 1990s.

aerial

防銹

Telescopes in Orbit and New Telescopes on Mountaintopsge telescope in astronomy for several decades. It was a long and tedious process to top this great technological achievement: a Russian 6-meter telescope approximated the quality of its predecessor only much later and after a number of necessary improvements, and the jump to 8-meter-class telescopes did not occur until the beginning of the 1990s.

背書

無能的人

Stellar Nurserieshot; in others, dense and cold. When the interstellar matter is hot . dense, we can see glowing nebulae, called H-II (hydrogen-II) regions. Hydrogen, the simplest atomic element, consists of one proton in the nucleus and one electron. H-II is ionized hydrogen — hydrogen that has lost its electron and acquired a positive electrical charge.