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