Астронет: Астрономическая картинка дня NGC 4414: сказочная спиральная галактика http://variable-stars.ru/db/msg/1163142/eng |
Credit & Copyright: W. Freedman
(Carnigie Obs.)
, L. Frattare
(STScI)
et al.,
& the Hubble Heritage Team (AURA/ STScI/ NASA)
Explanation:
How far away is this galaxy?
Cosmologists the world over have been working hard to find out.
Spiral galaxy
NGC 4414 contains many
Cepheid variable stars
that oscillate in a way that allows
astronomers to estimate their distance.
From analyzing distances to galaxies like this,
some astronomers have
recently announced
that they have again refined their estimate of the
expansion rate of the universe.
The running debate over this
rate is not yet over, however,
as another group of astronomers has
recently announced a distance that corresponds to a smaller universe expansion rate from a
completely new method.
NGC 4414 shows many classic
spiral galaxy features,
including thick
dust lanes,
a central region rich in old red stars,
and winding spiral arms glowing with young blue stars.
Even classic spirals contain new surprises, though, as an
unusual blue variable object has recently been found in
NGC 4414.
& the Hubble Heritage Team (AURA/ STScI/ NASA)
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official: Jay Norris.
Specific
rights apply.
A service of:
LHEA at
NASA /
GSFC
& Michigan Tech. U.