Meade Image Processing Uživatelský manuál stáhnout pdf (Strana 8)

but not dark blue; grey toward the horizon; and the setting Sun is yellow but it does not

vanish behind clouds long before setting. Some moving clouds are not a problem, these

usually dissolve before dark. One in five nights is such in Mississippi.

The majority of nights is, however, useless. At sunset, the sky is grey, even if the Sun is

(sort of) visible; there is obvious haze. After dark a few stars peek out faintly but faint stars

do not show. Such weather is quite disappointing, because it gives the impression that some

success is possible, but any real work becomes painfully difficult.

And, of course, there are those nights, half the time, when the sky is cloudy, or it is

raining.

Another aspect of astronomical observations is lunation. When the Moon is bright, its

light makes it all but impossible to observe faint objects. Starting from a day or two before

first quarter, for two weeks the Moon is too bright; and think of it, that takes out half of the

time.

When we add together all these constraints, and take out the nights when there is a

campus event such as a game, it is obvious that the most precious commodity for an

astronomer in Mississippi is a clear night. We cannot afford to skip a good night because we

are tired, or because it falls on a weekend or a night we’d rather spend with a friend. We must

use the first chance we have because we may not get another one.

1 2 3 4 5 6 7 8 9 10 11 12 13 ... 28 29

Žádné komentáře

Meade Image Processing Uživatelský manuál Strana 8