Spring 2012 Astronomy CourseMississippi Valley Night Sky ConservationThe Sky Around Us
Program developed byMississippi Valley Conservation AuthorityRoyal Astronomical Society of CanadaOttawa Astronomy Friends
Instructors:Pat BrowneStephen CollieRick Scholes
Earth Centered Universe software for illustrations – courtesy David Lane
WHERE Locating Star Clusters
WHEN Are they Visible?
WHAT Types of star clustersOpen Clusters
WHOPioneers in star cluster analysisHelen Sawyer Hogg(Canadian Astronomer)
III Star Clusters in and around our Galaxy
Introduction to Star Cluster Observing
What’s up ? Is the Moon up? Where’s our meridian?What can we see when the Moon is up…
For clusters of stars, or specialnebulous stellar bodies, or galaxies, the moon , like light pollution obscures the photons emitted from these objects.
Where’s our meridian?Galaxies galore coming up close
to our local meridian…Open Clusters setting in the
West…Globular Clusters in the East
WHAT:Open clusters:Widely-spaced groupings of easily resolvable
starsAlso called Galactic
Clusters because they lie i
Observing Spring Open Clusters
Monoceros: M46, M47
Cancer : M44, M67
Auriga: Clusters,M38,M36,
M37 (West)
Meridian
Open Clusters looking West (setting)( Spring time Northern Hemisphere)
Auriga cluster M38, M36,M37
Monoceros Cluster M46, M47
M44 – ‘Beehive’
Modest neighbour M67
Winter (west) Milky Way
From a true, dark sky, nothing can compare to
a naked eye view of the
Milky Way. During the winter months in the Northern Hemisphere, we face
away from the furiously busy
core of our home galaxy and
lookoutward, through its
more tenuous periphery. Despite being more
delicate, this slice of the Milky
Way is still rich with structure. http://www.perezmedia.net/beltofvenus/archives/001397.html
Open Clusters and NebulousRegions in Constellation AurigaAuriga
Auriga contains an nteresting variety: many open clusters and nebulous regions simply because the Milky Way runs through it.
3 Open clusters in/out of pentagon of ConstellationAuriga south of Capella.
M37 the richest cluster containing over
500 stars spread across 20 arcminutes and is the brightest ofthe 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-
yearsaway, can be seen with a small
telescope.Courtesy - Dave Garner teaches astronomy
at Conestoga
Observing Log Book
Suggesteed Recording Format
(Do what’s comfortable for you)
Header:Observation NumberObservation Date and TimeObserving InstrumentTelescope/EyePiece CombinationObserving Conditions – Temperature, Wind,
moon phaseReferences – Books, Sky Charts,etc
Body:Guests or observing companionsEach object – Designations commonly include
thosefound in in the RASC Observers Handbook :
Messier NGC David Levy GemsMethodology for Finding the ObjectImpressions of the object
This log book won the RASC Ottawa Center Observer of the Year Award 2004 . Lack of neatness is forgiven in favour of persistence in recording (even after a long night).
First Quarter Moon in the West – Waxing
Crescent – sets after midnight!
When the Moon is UP!
Accessibility to darkness of the night skyMilky way only visible wth moderately dark skiesFaint objects like clusters of stars, ane even galaxies an
be naked eye objects with very dark skies not even visible in a telescope from moderately dark skies
When we are in the phase of the moon from First Quarter to Full
moon, we can see how much light (even natural light) can obscure
the fainter celestial objects
Fred Lossing ObservatoryOperated in the area by the Royal Astronomical Society
of Canada (RASC) 16” telescope with research grade optics
produced by NRC The only observatory in Canada to boast the discovery of 5 Comets
Good Neighbour LightingShielded lighting directing light towards buildings and
groundReduced glare means more effective security Light goes where it is needed reducing electricity by 30% for the same resultsMississippi Mills By-law for Outdoor IlluminationLight pollution abatement Conservation of the night sky
Night Sky Conservation – Impact of Lighting Up the Night Sky
This is a video on the need to reduce light ing up the night. You can download this: http://www.millstonenews.com/2012/03/the-mississippi-valley-conservation-authority-will-once-again-be-offering-its-astronomy-course-at-the-mill-of-kintail-on-fri.html
Sky measuring: Brightness and Size of objects:Given a dark location reasonably free of unshielded lighting (referred to as "light pollution"), this scale describes what is shown when you query ECU about Magnitudes:
http://www.mpas.asn.au/MembersInfo/viewing/smohr/ApparentMag/ApparentMag.htm
Magnitudes on a Sky Chart
and in the sky…So that when we see Mars is at magnitude -0.2 with anangular width of 10.7” we know, it’s bright, and can be seenin binoculars , but better yet in a telescope.
Observing naked eye and with optical aids…
Compare the size and
magnitude of the Beehive cluster vs.
the other Open Cluster in Cancer: M67 (much smaller, fainter, and one of the oldest star clusters known…
Now go do the OpenCluster
exercise!
Beehive Cluster – Praesepe – size 95’ (> deg) Magnitude 3.1
M67: size 29 ‘ (1/3 deg)
Magnitude 6.9