Download Slide 1 - Typepad

Spring 2012 Astronomy Course
Mississippi Valley Night Sky Conservation
The Sky Around Us
Program developed by
Mississippi Valley
Conservation Authority
Royal Astronomical Society
of Canada
Ottawa Astronomy Friends
Instructors:
Pat Browne
Stephen Collie
Rick Scholes
Earth Centered Universe
software for illustrations –
courtesy David Lane
Spring Galaxy hunt
WHERE
Locating Galaxies by star-hopping
Observing individual island Universes (poetic term)
Observing interacting galaxies
Observing clusters of galaxies (Virgo)
M51 Whirlpool
Galaxy
M51
WHEN
Are they Visible?
Spring time ! – due to our point of view on earth at this time of year
WHAT
Types of Galaxies
(Face on,
Edge on,
Elliptical,
Spiral,
Barred Spiral,
Irregular,
Peculiar)
WHERE: > 2 Million Light Years beyond the milky way
Famous Examples:
M64 – Blackeye Galaxy - Spiral
M51 – Whirlpool Galaxy - Interacting
Virgo Cluster of Galaxies – Our Local Group
M65,M66 (and NGC 3628) – The Leo Triplet, M65, face on, M66
Edge On)
M64
BlackEye
Calaxy M64
M65.M66
Leo
Triplet
Find a spiral galaxy M64 – The BlackEye
Galaxy
M51 Whirlpool
Galaxy
Locate the Right Angle of the constellation
Coma Berenices
Meridian
You will see a swam of stars in there,
Melotte 111 (Coma Star Cluster) Star Cluster
in Coma Berenices– this is an open cluster!
BlackEye
Calaxy M64
But we are after something much farther away
outside of the Milky WAY!
Locate the brightest star in Coma: Alpha
Comae
Alpha
Comae
M64 is ~½ way between the diagonal of
the Coma Constellation
In the middle there is a bright star 35
Comae about 1 deg SW of M64
M64 is brighter than 10 billion suns
(luminousity). However this depends on
our distance estimate. Estimates of 10
to 40 Million Light Years are used for
M64. Black band is dust which obscures
part of the nucleus of the galaxy.
35
Comae
Galaxies … Where…
Past the Milky Way… to other systems with billions of
stars…
As we dart away from our home galaxy at many times
the speed of light to get to the next cluster of
galaxies in the constellations of Virgo and Coma
Berenices, we travel some 50 million light years
As we reach the galaxies of Virgo and Coma
Berenices, we realize that our local group is
bound to this cluster –thousands of galaxies are
sharing the same part of space, sharing the same
destiny…
(Deep Sky Objects, David Levy, p 188)
Find an interacting galaxy M51 –
The Whilrpool Galaxy
Locate the handle of the
Big Dipper
(star is called Alkaid)
Locate the brightest star
in the constellation
Canes Venatici. This is
Alpha CVn,
(a famous double star
called Cor Coroli)
M51 is 1/3 the way to
Cor Coroli from Alkaid
(the handle of the big
dipper)
M65,M66 and NGC 3628
The Leo Triplet
System of Galaxies
Spirals: Face and Edge-ON
Find the three stars which make
up the hind quarter of Leo.The
lower right star is called Chort.
Travel down until you see a
dimmer star 73 Leonis. The
galaxies are just southwest…