Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.arcetri.astro.it/~palla/ANDREAIMMAGINI/ISM/Varie.txt Дата изменения: Tue Jan 30 14:35:23 2001 Дата индексирования: Sat Dec 22 07:41:25 2007 Кодировка: Поисковые слова: annular solar eclipse

EMBARGOED UNTIL: 1:00 P.M. (EST) DECEMBER 17, 1997

PHOTO NO.: STScI-PRC97-38b


HUBBLE'S PLANETARY NEBULA GALLERY


[Top left] - IC 3568 lies in the constellation Camelopardalis
at a distance of about 9,000 light-years, and has a diameter
of about 0.4 light-years (or about 800 times the diameter of
our solar system). It is an example of a round planetary nebula.
Note the bright inner shell and fainter, smooth, circular
outer envelope.

Credits: Howard Bond (Space Telescope Science Institute),
Robin Ciardullo (Pennsylvania State University) and NASA


[Top center] - NGC 6826's eye-like appearance is marred
by two sets of blood-red "fliers" that lie horizontally across
the image. The surrounding faint green "white" of the eye
is believed to be gas that made up almost half of the star's
mass for most of its life. The hot remnant star (in the center
of the green oval) drives a fast wind into older material,
forming a hot interior bubble which pushes the older gas
ahead of it to form a bright rim. (The star is one of the
brightest stars in any planetary.) NGC 6826 is 2,200 light-
years away in the constellation Cygnus. The Hubble telescope
observation was taken Jan. 27, 1996 with the Wide Field and
Planetary Camera 2.

Credits: Bruce Balick (University of Washington),
Jason Alexander (University of Washington), Arsen Hajian
(U.S. Naval Observatory), Yervant Terzian (Cornell
University), Mario Perinotto (University of Florence, Italy),
Patrizio Patriarchi (Arcetri Observatory, Italy) and NASA


[Top right ] - NGC 3918 is in the constellation Centaurus
and is about 3,000 light-years from us. Its diameter is about
0.3 light-year. It shows a roughly spherical outer envelope
but an elongated inner balloon inflated by a fast wind from
the hot central star, which is starting to break out of the
spherical envelope at the top and bottom of the image.

Credits: Howard Bond (Space Telescope Science Institute),
Robin Ciardullo (Pennsylvania State University) and NASA


[Bottom left] - Hubble 5 is a striking example of a "butterfly"
or bipolar (two-lobed) nebula. The heat generated by fast
winds causes each of the lobes to expand, much like a pair
of balloons with internal heaters. This observation was taken
Sept. 9, 1997 by the Hubble telescope's Wide Field and
Planetary Camera 2. Hubble 5 is 2,200 light-years away in
the constellation Sagittarius.

Credits: Bruce Balick (University of Washington),
Vincent Icke (Leiden University, The Netherlands),
Garrelt Mellema (Stockholm University), and NASA


[Bottom center ] - Like NGC 6826, NGC 7009 has a bright
central star at the center of a dark cavity bounded by a
football-shaped rim of dense, blue and red gas. The cavity
and its rim are trapped inside smoothly-distributed greenish
material in the shape of a barrel and comprised of the star's
former outer layers. At larger distances, and lying along
the long axis of the nebula, a pair of red "ansae", or
"handles" appears. Each ansa is joined to the tips of the
cavity by a long greenish jet of material. The handles are
clouds of low-density gas. NGC 7009 is 1,400 light-years
away in the constellation Aquarius. The Hubble telescope
observation was taken April 28, 1996 by the Wide Field
and Planetary Camera 2.

Credits: Bruce Balick (University of Washington),
Jason Alexander (University of Washington),
Arsen Hajian (U.S. Naval Observatory), Yervant Terzian
(Cornell University), Mario Perinotto (University of Florence,
Italy), Patrizio Patriarchi (Arcetri Observatory, Italy), NASA


[Bottom right ] - NGC 5307 also lies in Centaurus but is about
10,000 light-years away and has a diameter of approximately
0.6 light-year. It is an example of a planetary nebula with a
pinwheel or spiral structure; each blob of gas ejected from the
central star has a counterpart on the opposite side of the star.

Credits: Howard Bond (Space Telescope Science Institute),
Robin Ciardullo (Pennsylvania State University) and NASA