Astronomy For Teachers
• What• Where• When• How• Why• Who
Finding Events, Phenomena, Objects
Methods of viewing
Science behind it all
You and your students
What is happening up there?
• Resources for information–Magazines (and their websites)– Almanacs – On-line• Space Weather (.com)• Heaven’s Above (.com)• Sky Maps (.com)
– Astronomy Clubs– TV (Jack Horkheimer)
Where do I look to see these things?
• Positions in the sky – two systems– Equatorial System (Right Ascension and
Declination)– Alt-Az System (Altitude and Azimuth)
• To convert from one to the other…..COMPLICATED!!!!!Best to use a computer
RA and Dec
• Analogous to latitude (dec) and longitude (RA)
• Declination range-90º to +90º90º S to 90º N1º = 60′, 1′ = 60′′
• RA – increases eastward0h, 1h, 2h, 3h, … 22h, 23h, 0h
1h = 60m, 1m = 60s
Alt-Az System
• Altitude – angular height of object above horizon (how high up is it)0º = horizon90º = zenith
• Azimuth – angle away from due northNorth = 0º East = 90º South = 180º West = 270º
9 PM 10 PM
When will it be visible?
• What is your latitude/longitude/time zone?• When is Daylight Savings Time in effect?• Universal Time (UT)
5 hours ahead during DST6 hours ahead the rest of the year
How do I observe these things?
• Naked Eye Observing – Large Scale– Constellations– Asterisms– Milky Way– Aurora*– Meteor showers†
– Refraction events*– Satellite fly-overs †
* Unannounced† Predictable
Measurements
• PositionsUse the “Rule of Thumb” (and fist and hand)One thumb ≈ 2º One fist ≈ 10º One “hang-ten” ≈ 20º • Brightness – use surrounding stars/objects
Star Charts
• Printed Charts / Computer programs
Planispheres
Binoculars
• Good– Higher magnification– Gathers more light
• Nebula• Bright clusters• Bright comets• Milky Way
– Orientation– Other uses
• Bad– Stability– Two eye focus– Two arms
Evaluating Binoculars
Two numbers7 x 35, 8 x 50, etcFirst Number = magnificationSecond Number = aperture (mm)
AssessmentMultiply = quick estimateDivide = exit pupil (mm)
Which is the best?
Magnification Light Gathering Exit Pupil Cost
20 x 50 8 x 25 10 x 50
You get what you paid for….
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