Tag Archives: church

Electrum and Lead

by John Church Let them draw together the bones of the metal.           – Ezra Pound, The Alchemist I venture that one reason amateur astronomers like their hobby so much is that despite all the turmoil here on Earth, the heavens … Continue reading

Posted in February 2022, Sidereal Times | Tagged , | Leave a comment

A Close-Focusing Test with the Hastings-Byrne Refractor

by John Church In recent issues of Sidereal Times I’ve been discussing whether our 1879 Hastings objective was designed using John Herschel’s 1822 procedure.  Herschel’s method was a major advance that gave very good results for its time.  As part … Continue reading

Posted in June 2021, Sidereal Times | Tagged , , | Leave a comment

John Herschel and his Lens Designs

by John Church Charles Hastings once wrote that the lens which is now on our Hastings-Byrne refractor was similar in design to the types described by John Herschel (1792-1871). He also mentioned that such lenses do not greatly differ from … Continue reading

Posted in April 2021, Sidereal Times | Tagged , , | Leave a comment

How Did Hastings Design Our Objective? Part Two

by John Church Objectives for smaller telescopes are sometimes designed to conform to the “Herschel condition” proposed by John Herschel in two papers in the early 1820’s.  These objectives perform well at nearby distances as well as on celestial objects … Continue reading

Posted in March 2021, Sidereal Times | Tagged , | Leave a comment

How Did Hastings Design Our Objective?

by John Church PART I I’ve often wondered what actual methods Charles Hastings used when designing the 6-1/4” objective now sitting at the business end of our fine refractor in Washington Crossing State Park.  I’ll start by quoting Hastings’ own … Continue reading

Posted in February 2021, Sidereal Times | Tagged , , | Leave a comment

From the Program Director

by Victor Davis The first AAAP meeting of 2021 will take place (virtually) on Tuesday, January 12th at 7:30 PM. (See Joining the Meeting with Zoom below for details). This meeting is open to AAAP members and the general public. … Continue reading

Posted in January 2021, Sidereal Times | Tagged , , | Leave a comment

Some Notable Conjunctions of Jupiter and Saturn

by John Church As we are all aware, there will be a close conjunction of Jupiter and Saturn in the evening sky of Monday Dec. 21, which coincidentally is the same day as the winter solstice.  Jupiter passes Saturn once … Continue reading

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Mars Opposition Photos from the Past

by John Church Left Picture: August 18, 1971         Right Picture: Oct. 11, 1973 Edmund 4-inch refractor            Hastings-Byrne 6¼ inch refractor Angular diameter 24.7 arcsec           Angular diameter 21.4 arcsec Central Meridian 10º              Central Meridian 328º                        Published in Sky & Telescope, March … Continue reading

Posted in November 2020, Sidereal Times | Tagged , | Leave a comment

Nominations for AAAP Officers for 2020-21

by John Church, Nominations Chair Dear Members, Director Rex Parker has kindly asked me to serve as Nominations Chair for our upcoming May election. I am therefore very pleased to report that all of our present officers have agreed to … Continue reading

Posted in April 2020, Sidereal Times | Tagged , , , | Leave a comment

Freeman J. Dyson: A Personal Remembrance

by John Church The Amateur Astronomers Association of Princeton joins the world in mourning the passing of renowned mathematical physicist and noted author Freeman J. Dyson on February 28 of this year at the age of 96. Freeman, an Emeritus Professor … Continue reading

Posted in April 2020, Sidereal Times | Tagged , | Leave a comment