Lée or Lee is a commune in the Pyrénées-Atlantiques department in south-western France.
Lüe is a commune in the Landes department in Aquitaine in south-western France.
LE or le may refer to:
Cy, CY, or cy may refer to:
Halley's Comet or Comet Halley (/ˈhæli/ or /ˈheɪli/), officially designated 1P/Halley, is a short-period comet visible from Earth every 75–76 years. Halley is the only known short-period comet that is clearly visible to the naked eye from Earth, and the only naked-eye comet that might appear twice in a human lifetime. Halley last appeared in the inner parts of the Solar System in 1986 and will next appear in mid-2061.
Halley's returns to the inner Solar System have been observed and recorded by astronomers since at least 240 BC. Clear records of the comet's appearances were made by Chinese, Babylonian, and medieval European chroniclers, but were not recognized as reappearances of the same object at the time. The comet's periodicity was first determined in 1705 by English astronomer Edmond Halley, after whom it is now named.
During its 1986 apparition, Halley's Comet became the first comet to be observed in detail by spacecraft, providing the first observational data on the structure of a comet nucleus and the mechanism of coma and tail formation. These observations supported a number of longstanding hypotheses about comet construction, particularly Fred Whipple's "dirty snowball" model, which correctly predicted that Halley would be composed of a mixture of volatile ices – such as water, carbon dioxide, and ammonia – and dust. The missions also provided data that substantially reformed and reconfigured these ideas; for instance, now it is understood that the surface of Halley is largely composed of dusty, non-volatile materials, and that only a small portion of it is icy.
The Great Comet of 1823, also designated C/1823 Y1 or Comet De Bréauté-Pons, was a bright comet visible during the last month of 1823 and the first few months of 1824.
It was independently discovered by Nell de Bréauté at Dieppe on December 29, by Jean-Louis Pons on the morning of December 30, and by Wilhelm von Biela at Prague on the same morning. It was already visible to the naked eye when discovered: Pons initially thought he was seeing smoke from a chimney rising over a hill, but continued observing when he noticed it did not change appearance. He was later to note that the comet was, puzzlingly, more easily visible to the naked eye than through a telescope.
The comet was particularly known at the time for exhibiting two tails, one pointing away from the Sun and the other (termed an "anomalous tail" by Harding and Olbers) pointing towards it.
Pons was also the last astronomer to detect the comet, on April 1 1824.