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Details Title: ASTRONOMY 101 Description: CHAPTER 4 Total Flash Cards: 42 Created: 08/28/2007 16:40:00	To study from this set of flash cards, or to create your own your own study flash cards, register HERE. If you are already a registered user, CLICK HERE.
Cards Term ELECTROMAGNETIC RADIATION Definition LIGHT IS MADE UP OF BOTH ELECTRIC AND MAGNETIC FIELDS. Term WAVELENGTH Definition THE DISTANCE BETWEEN PEAKS Term NANOMETER (nm) Definition TOO AWKWARD TO MEASURE SUCH SHORT DISTANCES IN MILLIMETERS, SO PHYSICISTS AND ASTRONOMERS DESCRIE THE WAVELENGTH OF LIGHT USING EITHER THE UNIT OF __ Term ANGSTROM (A) Definition TOO ASKWARD TO MEASURE SUCH SHORT DISTANCES IN MILLIMETERS, SO PHYSICITS AND ASTRONOMERS DESCRIBE THE WAVELENGTH OF LIGHT USING EITHER THE UNIT OF BILLIONTH OF AMETER (10-9 M)___WHICH IS NAME AFTER THE SWEDISH ASTROMERS ANDERS ANGSTROM Term INFRARED (IR) Definition RADIATION, WITH WAVELENGTHS RANGING FROM 700 nm TO ABOUT 1 mm Term ULTRAVIOLET (UV) Definition ELECTROMAGNETIC WAES WITH WAVELENGTHS SHORTER THAN VIOLET LIGHT ARE CALLED Term X-RAYS Definition SHORTER-WAVELENGTH ELECTROMAGNETIC WAVES THAN UV ARE CALLED Term GAMMA RAYS Definition ARE THE SHORTEST WAVELENGTH ELECTROMAGNETIC WAVES THAN UV ARE CALLED Term PHOTON Definition A MINIMUM SIZED BUNDLED OF ELECTROMAGNETI WAVES. A PARTICLE OF LIGHT IS CALLED Term ATMOSPHERIC WINDOWS Definition ONLY VISIBLE LIGHT, SOME SHORT-WAVELENGTH INFRARED RADIATION, AND SOME RADIO WAVES REACH EARTH'S SURFACE THROUGH WHAT ARE CALLED Term REFRACTING TELESCOPES Definition A TELESCOPE TO FOCUS LIGHT BY USING A LENS TO GATHER AND FOCUS THE LIGHT Term REFLECTING TELESCOPES Definition TELESCOPE USE TO FOCUS LIGHT USING A MIRROR Term PRIMARY LENS Definition THE MAIN LENS INA REFRACTING TELESCOPE Term PRIMARY MIRROR Definition THE MAIN MIRROR IN A REFLECTING TELESCOPE Term EYE PIECE Definition BOTH KINDS OF TELESCOPES FORM A SMALL, INVERTED IMAGE THAT IS DIFFICULT TO OBERSERVE DIRECTLY, SO A LENS CALLED THE ____ IS USED TO MAGNIFY THE IMAGE AND MAKE IT CONVENIENT TO VIEW. Term FOCAL LENGTH Definition IS THE DISTANCE FROM A LENS OR MIRROR TO THE IMAGE IT FORMS OF A DISTANT LIGHT SOURCE SUCH AS A STAR. Term CHROMATIC ABERRATION Definition TELESCOPES HAVE SERIOUS DISADVANTAGES. MOST SUFFER FROM AN OPTICAL DISTORTION THAT LIMISTS THEIR USEFULNESS. WHEN LIGHT IS REFRACTED THROUGH GLASS, SHORTER WAVELENGTHS BEND MORE THAN LONGER WAVELENGTHS. AS A RESULT YOU SEE A COLOR BLUR AROUND EVERY IMAGE. THIS COLOR SEPARATION IS CALLE ___ Term OPTICAL TELESCOPES Definition TELESCOPE TO GATHER VISIBLE LIGHT Term RADIO TELESCOPES Definition TELECOPE TO GATHER RADIO RADIATION. Term LIGHT GATHERING POWER Definition REFERS TO THE ABILITY OF A TELESCOPE TO COLLECT LIGHT. Term RESOLVING POWER Definition REFERS TO THE ABILITY OF THE TELESCOPE TO REVEAL FINE DETAIL Term DIFFRACTION FRINGE Definition ONE CONSEQUENCE OF THE WAVELIKE NATURE OF LIGHT IS THAT THERE IS AN INEVITABLE SMALL BLURRING CALLED A ___AORUND EVERY POINT OF LIGHT IN THE IMAGE, AND YOU CAN'T SEE ANY DETAIL SMALLER Term INTERFEROMETER Definition ONE WAY TO IMPROVE RESOLVING POWER IS TO CONNECT TWO OR MORE TELESCOPES IN AN ___WHICH HAS A RESOLVING POWER EQUAL TO THAT OF A TELESCOPE AS LARGE AS THE MAXIUM SEPARATION BETWEEN THE INDIVIDUAL TELESCOPES Term SEEING Definition IN ADDITION, WHEN YOU LOOK THROUGH A TELESCOPE, YOU LOOK THROUGH MILES OF TURBULENCE IN EARTH'S ATMOSPHERE, WHICH MAKES IMAGES DANCE AND BLUR, A CONDITION THA ASTRONOMERS CALL Term ADAPTIVE OPTICS Definition A SITUATION CAN BE IMPROVED BY A DIFFICULT AND EXPENSIVE TECHNIQUE CALLED ____IN WHICH RAPID COMPUTER CALCULATIONS ADJUST THE TELESCOPE OPTICS AND PARTLY COMPENSATE FOR SEEING DISTORTIONS. Term MAGNIFIYING POWER Definition THE LEAST IMPORTANT POWER OF A TELESCOPE IS ____THE ABILITY TO MAKE AN IMAGE LARGE Term LIGHT POLLUTION Definition optical astronomers avoid cities because ____the brightening of the night sky by light scattered from artifical outdoor lighting,can make it impossible to see faint objects Term SIDEREAL TRACKING (SIDEREAL, REFERS TO THE STARS) Definition TELESCOPES LOCATED ON THE SURFACE OF EARTH, WHETHER OPTICAL OR RADIO, MUS MOVE CONTINUOUSTLY TO STAY POINTED AT A CELESTIAL OBJECT AS EARTH TURNS ON ITS AXIS. THIS IS CALLED Term PHOTOGRAPHIC PLATE Definition WS THE FIRST IMAGE RECORDING DECISE USED WITH TELESCOPES. Term PHOTOMETERS Definition SENSITIVE LIGHT METERS TO MEASURE THE BRIGHTNESS OF INDIVIDUAL OBJECTS VERY PRECISELY. Term CHARGE COUPLED DEVICES (CCDs) Definition MOST MODERN ASTRONOMERS USE THIS AS BOTH IMAGE RECORDING DEVICES AND PHOTOMETERS Term ARRAY DETECTORS Definition CAN BE USED LIKE A SMALL PHOTOGRAPHIC PLATE, BUT THEY HAVE DRAMATIC ADVANTAGES OVER BOTH PHOTOMETERS AND PHOTOGRAPHIC PLATES. Term DIGITIZED Definition MEANING, CONVERTED TO NUMERICAL DATA, AND CAN BE READ DIRECTLY INTO A COMPUTER MEMORY FOR LATER ANALYSIS. Term FALSE COLOR IMAGES Definition ASTRONOMERS ALSO MANIPULATE IMAGES TO PRODUCE ____IN WHICH COLORS REPRESNT DIFFERENT LEVES OF INTENSITY AN ARE NOT RELATED TO THE TRUE COLORS OF THE OBJECT Term SPECTROGRAPH Definition TO ANALYZE LIGHT IN DETAIL, YOU NEED TO SPREAD THE LIGHT OUT ACCORDING TO WAVELENGTH INTO A SPECTRUM, A TASK PERFORMED BY A ___ Term SPECTRUM Definition VIOLET (SHORT WAVELENGTH) LIGHT BENDS MOST, ANDRED (LONG WAVELENGTH) LIGHT LEAST. thURS, THE WHITE LIGHT ENTERING THE PRISM IS SPREAD INTO WHAT IS CALLED Term GRADING Definition IS A PIECE OF GLASS WITH THOUSANDS OF MICROSCOPIC PARALLEL LINES SCRIBED ONTO ITS SURFACE Term SECONDARY MIRROR Definition CAN REFLECT THE LIGHT THROUGH A HOLE IN THE PRIMARY MIRROR TO A CASSEGRAIN FOCUS Term PRIME FOCUS Definition IN LARGER TELESCOPES THE LIGHT CAN BE FOCUSED TO A ____POSITION HIGH IN THE TELESCOPE TUBE. ALTHOUGH, IT IS A GOOD PLACE TO IMAGE FAINT OBJECTS, THE PRIME FOCUS IN INCONVENIENT FOR LARGE INSTRUMENTS. Term CASSEGRAIN FOCUS Definition THIS FOCAL ARRANGEMENT MY BE THE MOST COMMON FORM OF ASTRONOMICAL TELESCOPE. IT IS CONVENIENT AND HAS ROOM FOR LARGE INSTRUMENTS Term NEWTONIAN FOCUS Definition SMALLER TELESCOPES CAN USE OTHER FOCAL ARRANGMENTS. THE ____THAT ISAAC NEWTON USED IN HIS FIRST REFLECTING TELESCOPE IS AWKWARD FOR LARGE TELESCOPES Term SCHMIDT-CASSEGRAIN FOCUS Definition MANY SMALL TELESCOPES SUCH AS THIS ONE HAS A THIN CORRECTING PLACE IMPROVING THE IMAGE BUT IS TOO SLIGHTLY CURVED TO INTRODUCED SERIUOS CHROMATIC ABERRATION