~The von Rheticus Model Telescope

-terrestrial
-2 buttons(1 big, 1 small) for adjusting power
-Pressing either button tells current magnification as red number that shows for half a sec. and changes until you stop pressing
-Bigger button increases power by moving outer eyepiece farther from inner one
-Smaller button decreases power by moving outer eyepiece nearer to inner one
-Magnifying power ranges from 10-250
-There is an auto-focus knob; if not desired, pull focus knob out
-telescope is about 6 inches long and objective lens is 1 inch wide but it has just as good resolution as a Muggle made telescope
-the wider the objective lens of a muggle telescope is, the smaller the resolution
-A Muggle-built telescope with a 1 in. wide objective lens has at best a resolution of about 5 arcseconds.
-the greatest magnifying power of a telescope that is useful is about 250 divided by the resolution in arcseconds, or 20 times the width of the objective lens of a Muggle-built telescope
-increasing the power beyond that amount makes things look bigger but doesn’t improve the resolution, so objects just look blurred.
The greatest useful magnifying power of the von Rheticus telescope is about 250, which is why that’s its maximum power.
-Muggle-built telescopes near 12.5 centimeters must be attached to a tripod
-light
-the Scratch-Resistant Charm and the Break-Resistant Charm protect the fragile objective lens
-write your name on your lens cap
-Treat your telescope with care and respect and never use it as a weapon
-Never look at the sun or the full moon through a magical telescope. Both have enough magical power to destroy all the charms put on your telescope
-Looking at the sun through a telescope without a sun filter can blind you and crack your lens

~The Lunascope and the Moon Chart

-the night of a full or partly full moon is a bad time for stargazing
-A Lunascope looks similar to a telescope. Punch month, day and year into the side and it will tell you what phase the moon will be in in picture form
-A moon chart is a piece of parchment that has 10 consecutive days, each with a picture of the correct moon phase. Touching the right side shows next 10 days, touching left side shows previous 10 days

~The Celestial Globe

-Similar to terrestrial globe except instead of showing earth, it shows constellations and stars, some with names
-Some show mirror images of constellations as seen from earth and some invert to show stars exactly as seen from earth
-shows planets, moons, and the sun and names of them and see where they were/will be on a given day magically
-Valuable for astrology

~Other Astronomical Tools

-Orrery: Model of solar system, with planets moving around the sun
-The planets are not to scale as it would be much too large otherwise
-Planet movements are to scale
-Planets float in the air and are enchanted to move
-Used more for educational than research purposes
-Star Chart: Used my magical people and Muggles, it's a flat map of the sky and helps you locate stars/constellations
-No magical properties
-Won't help with finding planets
-It takes about a 1/2 hr to see in the dark fully, so use red light
-Used by(magical and muggle) astronomers, the astronomer's lamp emits controllable pure red light(adjustable brightness)

~Viewing Tips

-Don't try to locate objects while telescope is on high power
-Look away from the center of the viewing field when trying to find dim objects
-Stars twinkle, planets don't
-star's biggest angular size is Betelgeuse (0.044 arcseconds), planet's smallest angular size is Neptune (2.2 arcseconds at the minimum).

~Assignments

-Extra-credit essay(Buying a Telescope)
-Mandatory quiz