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MilkyWay
MILKY WAY
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The Milky Way is the galaxy where
the Solar System (and the Earth) is located. It is
a barred spiral[4] galaxy of a Local Group of
galaxies within the Virgo Supercluster. The main
disk of the Milky Way Galaxy is about 80,000 to
100,000 light-years in diameter, about 250,000 to
300,000 light-years in circumference, and outside
the Galactic core, about 2,300–2,600 light-years
in thickness.[5] The galaxy is estimated to
contain 200[6] billion stars but this number might
reach 400 billion[7] if small-mass stars
predominate. As a guide to the relative physical
scale of the Milky Way, if the galaxy were reduced
to 130 km (80 mi) in diameter, the solar system
would be a mere 2 mm (0.08 inches) in width. The
Galactic Halo extends outward, but is limited in
size by the orbits of the two Milky Way
satellites, the Large and the Small Magellanic
Clouds, whose perigalacticon is at ~180,000
light-years.[8] New discoveries indicate that the
disk extends much farther than previously thought.
The term "milky" originates from
the hazy band of white light appearing across the
celestial sphere visible from Earth, which
comprises stars and other material lying within
the galactic plane. The galaxy appears brightest
in the direction of Sagittarius, towards the
galactic center. Relative to the celestial
equator, the Milky Way passes as far north as the
constellation of Cassiopeia and as far south as
the constellation of Crux, indicating the high
inclination of Earth's equatorial plane and the
plane of the ecliptic relative to the galactic
plane. The fact that the Milky Way divides the
night sky into two roughly equal hemispheres
indicates that the solar system lies close to the
galactic plane. The Milky Way's visual absolute
magnitude is −20.9[9]
The Milky Way is but one of
billions of galaxies in the observable universe
(between 1×1010 and 8×1010). The Greek philosopher
Democritus (450 BC–370 BC) was the first known
person to claim that the Milky Way consists of
distant stars.
(From Wikipedia, the free
encyclopaedia) |
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Public Viewing
Nights |
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Just to let
everyone know, public viewing nights are held
every first Friday of the month. Clear or cloudy
nights the public viewing night goes ahead.
Members man a number of telescopes of various
sizes and types, and for those nights where the
sky is cloudy, extended astronomical presentations
are presented in the MPAS Viewing Centre.
So please come
along and enjoy our nights sky.
How to
get Here
(Click Here)
In 2011 MPAS
will host VASTROC.
For more information, click
here...
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