Astronomy For Teachers

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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