A L A C H U A A S T R O N O M Y C L U B

APRIL, 1988 THE ALACHUA ASTRONOMY CLUB MEETS THE SECOND TUESDAY OF EACH MONTH AT THE DOYLE CONNER BUILDING, S.W. 34th STREET AND 20th AVENUE AT 7 PM. EVERYONE INTERESTED IN ASTRONOMY IS INVITED TO ATTEND. CALL CHARLES TARJAN AT 377-7403 FOR MORE INFORMATION ON MEETINGS AND OTHER ACTIVITIES.

SPECIAL EVENT! SPECIAL EVENT! Carl Sagan, popular astronomer, announced that OUR Club is to be featured

in his latest TELEVISION SERIES "Amateur Astronomers...WaIking Where FOOLS Dare Not Go". He is planning to meet with the Club on April One, so plan to attend and share in this epic event.

PROGRAMXPROGRAM*PROGRAM-

On Tuesday evening, April 12, Bill Owen, a member of the Voyager navigation team at JPL, Calif, will present:

*X* "PROJECT VOYAGER-EXPLORATION OF THE OUTER PLANETS" ***

A REAL SPECIAL EVENT...NO FOOLING! On APRIL 9, SATURDAY EVENING at 7:30 P.M., Club members are meeting at the)

University of Florida Student Observatory where we can use a variety of tele-scopes. The observatory is located just east of the waste treatment plant on the south side of Mueseum Road. Some parking is available at the observatory, more is available about one-half block east across from the Reitz Union. Come and take part. The last quarter moon should be perfect!

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MARS IS COMING. MARS IS COMING! Randy Warren mentioned that many clubs are gearing up for the coming

opposition of MARS later this year (perhaps the best in 21 years), and has suggested that the AAC take part in a MARS WATCH, in which we consistantly observe, draw, and photograph the planet as it journeys toward us. He will discuss this at the coming meeting.

ASTRONOMY DAY...APRIL 23... Randy also mentioned that the UF Astronomy Department is planning some

activities on the 23rd. Hopefully he will have gathered more information on this to present to us at the meeting Tuesday evening.

DO YOU HAVE SOMETHING NEW WE MIGHT WANT TO KNOW ABOUT???? BRING IT TO THE MEGT1 N& I

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FIRSTLIGHT, PAGE TWO

(Editor's Note...the following copy was sent to Melrose via telephone one evening...a first! So, crank up your computer and give FIRSTLITE some interesting tidbits. We can also share programs this way too!)

DID YOU KNOW???? NO.3 C TARJAN

SEVERAL OF OUR MEMBERS DO NOT YET HAVE A TELESCOPE, BUT DO OWN BINOCULARS. THE USUAL REASON BEING THAT THEY WANT TO MAKE SURE, THAT WHEN THEY BUY A TELESCOPE, THEY WILL KNOW A LITTLE ABOUT WHAT THEY ARE BUYING. WELL, DID YOU KNOW THAT BINOCULARS CAN BE MORE USEFUL TO THE BEGINNER THAN SMALL TELESCOPES. THEN TOO, BINOCS ARE USEFUL FOR OTHER ACTIVITIES AND THE IMAGES ONE SEES IS RIGHTSIDE UP, AND NOT INVERTED AS ONE SEES THROUGH TELESCOPES. THE WIDE FIELD OF VIEW AND LOW MAGNIFICATION BINOCULAR OPTICS PROVIDE MAKES THE INSTRUMENT IDEAL FOR SWEEPING THE SKIES, OBSERVING STAR CLUSTERS, VIEWING TAILS OF COMETS THAT ARE TOO FAINT FOR THE NAKED EYE, YET TOO INDISTINCT FOR LARGER TELESCOPES WITH HIGH MAGNIFICATION.

BINOCULARS ARE TWO (BIN) SEPARATE OCULARS WHICH ARE JOINED TOGETHER BY A PIVOTING BRIDGE WHICH ALLOWS THE USER TO ADJUST THE INSTRUMENT TO FIT BOTH EYES. ON THIS BRIDGE ONE USUALLY FINDS A FOCUSING WHEEL. EACH "OCULAR" IS A CASING WHICH CONTAINS AN EYEPIECE, REFLECTING PRISMS WHICH FOLD THE LIGHT BACK AND FORTH (EFFECTIVELY REDUCING THE LENGTH OF THE INSTRUMENT), AND A ROUND OBJECTIVE OR OBJECT GLASS OF A CERTAIN APERTURE (WIDTH). THE PATH OF LIGHT RAYS THEN COMES FROM THE OBJECT BEING VIEWED THROUGH THE OBJECTIVE, IS FOLDED BY THE PRISMS, AND DIRECTED THROUGH THE EYEPIECE INTO THE VIEWER'S EYE.

IN CHOOSING BINOCULARS FOR SERIOUS OBSERVING, CONSIDER OBTAINING PRISMATIC BINOCULARS. BE AWARE THOUGH THAT IN BUYING A PAIR THE MAGNIFICATION AND APERTURE ARE THE MOST IMPORTANT CONSIDERATIONS. MAGNIFICATION, OF COURSE, IS IMPORTANT BUT APERTURE (GIVEN IN mm OR MILLIMETERS — 25mm EQUAL AN INCH) IS EQUALLY AS IMPORTANT. FOR MOST GENERAL PURPOSES, APERTURES OF 40-50mm ARE ADEQUATE. BINOCS WITH LARGER APERTURES ALLOW FAINTER OBJECTS TO BE SEEN BUT THE GREATER THE APERTURE, THE HEAVIER THE BINOCULAR. THESE MAY REQUIRE SOME FORM OF SUPPORT, OTHER THAN TWO ARMS, FOR EFFECTIVE VIEWING.

THE PUPIL OF YOUR EYE, IN DARKNESS, IS ABOUT 7-Bmm. THEREFORE THE BUNDLE OF LIGHT RAYS COMING FROM THE VIEWED OBJECT THROUGH THE EYEPIECE (THE EXIT PUPIL) AND REACHING YOUR EYE MUST NOT BE WIDER THAN 7-Bmm OR ELSE THE LIGHT GATHERED BY THE OBJECTIVE IS BEING WASTED. THIS CAN READILY BE CHECKED BY DIVIDING THE APERTURE BY THE MAGNIFICATION. AS AN EXAMPLE, 7 X 50 BINOCULARS WOULD HAVE AN EXIT PUPIL SLIGHTLY GREATER THAN 7mm (50/7), WHICH FALLS WITHIN THE ACCEPT IBLE RANGE.

(INFORMATION EXTRACTED FROM "ASTRONOMY, A STEP-BY-STEP GUIDE TO THE NIGHT SKY", MACMILLAN PUBLISHING COMPANY)

EDITOR'S NOTE...as mentioned above, the above was sent via modem to my computer, and I printed it as received (mostly). My computer likes 80 column width, plain ASCII (non-document) files...We can do this day or night, at home or work, and it saves me TONS of typing! Thanks!

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A GUIDE TO A GOOD VIEWING SITE GEORGE RUSSELL Below is a map showing how to get to the much talked about viewing site

off S.W. 75th. Street. George writes that HAILE PLANTATION is made up of a number of small "communities" and the map identifies these, as well as streets.

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EDITORIAL COMMENT! The Club President sent a letter recently to be printed in FIRSTLITE,

in which he asked you to help out by providing material for this newsletter. As Editor I want to expand it a bit. I have noticed two things about the club; one is that we are not growing, not reaching the community. The other is that the SAME people each month send me something. WHERE ARE THE REST OF YOU! This club is not only a gathering of us, it could be the basis for some very exciting and permanent different futures in this area. What is a different future? How about a club-owned observatory and astronomy center? Or, years away, but... a Planitarium that we convinced the city to build! Or, a major gathering of amateurs of national import...Big dreams. Possible dreams, if you take part! Lets do something important, now, starting by building a strong, viable group.

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