Transcript 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
Nebulae in clusters and around our Galaxy
WHERE
Locating Nebulae in Clusters
Observing nebulousity around individual stars
WHEN
Are they Visible?
WHAT
Types of Nebulae
Open Clusters and their Nebulae
WHERE: > 500 light years
(M42 is located at a distance of 1344 ± 20 light years and is the
closest region of massive star formation to Earth.)
This is much further out than…
Nearest and Brightest stars 5-15 light years
Consider: Lecture 1,II – Stars on the
celestial sphere < 500 light years
Famous Examples:
Pleiades
M42 trapezium
(Astronomers suspect that shockwaves from a supernova
explosion in Orion's head, nearly three million years ago,
may have initiated this newfound birth).
Introduction to Nebulae Observing
Nebulae in ‘young’ star clusters
Past the near objects, the planets, and beyond
the double and variable stars is a special
realm.
Here are the star clusters, gas clouds and star
nurseries.
For most purposes it can be assumed that
the stars in a given cluster formed
simultaneously from the same parent cloud
of gas and dust.
When comparing star clusters, we often
note the density of stars, their age and their
chemical composition (as revealed by their
spectra ).
Young Star clusters also often exhibit nebulous
trails of gas and dust which emanate from
members that are still in the process of
becoming stars! Also, those young stars often
continue to radiate and reflect off of the dusty
lanes that mark their birth into the cluster.
Open Clusters looking West (setting)
( Spring time Northern Hemisphere)
WHAT:
Nebula in Open Clusters
Observing (Winter) nebula
in the Spring
Western Sky
Orion: M42, M78
Pleides: M45
Perseus: Double Star
Cluster further NW
(not shown)
Open Clusters and Nebulous
Regions in Constellation Auriga
Auriga
Auriga contains an interesting variety:
many open clusters and nebulous
regions simply because the
Milky Way runs through it.
3 Open clusters in/out of
pentagon of Constellation
Auriga south of Capella.
M37 the richest cluster containing over
500 stars spread across 20
arcminutes and is the brightest of
the three with an apparent magnitude +5.6.
M36 - 60 stars with an angular width of 12
arcminutes.M38 100stars and is the
dimmest of the three at magnitude+6.4.
All three of these clusters, 4000 light-years
away, can be seen with a small telescope.
Courtesy - Dave Garner teaches astronomy at
Conestoga
Observing nebulousity In Clusters in the western sky
Observe:
M42, the Great Orion Nebula
M78 – Can you see the nebulousity in the double pair?
M45 – Pleiades (the 7 sisters) – Can you see the nebulousity
NGC 864, 869 : Double Cluster in Perseus (where’s the nebulousity?)
NGC
864,869
M78
M42
M45