by Victor Davis

The first AAAP meeting of 2021 will take place (virtually) on Tuesday, January 12^th at 7:30 PM. (See Joining the Meeting with Zoom below for details). This meeting is open to AAAP members and the general public. Due to the number of possible attendees, we will use the Waiting Room. This means when you login into Zoom you will not be taken directly to the meeting. The waiting room will be opened at 7:00 PM. Prior to the meeting start time (7:30 PM) you may socialize with others in the waiting room. The meeting room has a capacity of 100 people.

For the Q&A session, you may ask your question using chat or may unmute yourself and ask your question directly to the speaker. To address background noise issues, we are going to follow the rules in the table below regarding audio. If you are not speaking, please remember to mute yourself. You are encouraged, but not required to turn your video on.

Only the Business part of the meeting will be locked.

Featured Speaker: Longtime AAAP member John Church will give a talk entitled, The Fourth Condition: A Spyglass Drama. John’s presentation will summarize the steps leading up to the design of well-corrected doublet achromatic refractor objectives.

The starting point for such a design is to choose an aperture size and the desired focal length.  Next to be considered are what kinds of glasses are available, how best to minimize secondary color, spherical aberration, and finally coma. These design methods date from the pioneering researches of Alexis Clairaut, Jean le Rond d’Alembert and others in the 18^th century, since then adapted and republished by many others.  Equations for implementing their design principles were converted into a BASIC program published in Sky & Telescope (November 1984; V. 68, No 5, pp. 450-1).

John will discuss the design and performance of AAAP’s historic Hastings-Byrne 6 ¼ inch refractor, with remarks about Charles Hastings, the maker of its objective lens. He will show lunar photographs taken with this instrument. For a bit of drama, John will describe the scientific rivalry between Clairaut and d’Alembert.

Speaker’s Biography: A native of Richmond, John Church graduated from the University of Virginia with a bachelor’s degree in chemistry and then earned M.S. and Ph.D. degrees from Lawrence University in Appleton, Wisconsin.   His thesis work was concerned with the reaction of crystalline carbohydrate derivatives with oxygen under relatively mild conditions.  He spent his career in research and development with American Can Company at their Corporate R&D laboratory in Princeton and then with Colgate-Palmolive at their Corporate Research Center in Piscataway.

John is the author of sixteen scientific, historical, and technical publications, including several on the optics of refracting telescopes as well as one on close conjunctions of Jupiter and Saturn.  He holds ten U.S. patents and is the author of a book chapter on the chemistry of bleach. He has written three books and edited several others.  One of his Sky & Telescope articles traced the history of the 6 ¼ inch Hastings-Byrne refractor now installed in our observatory in Washington Crossing State Park, which he and many others helped build in the late 1970’s.

John has served as Assistant Director, Director, and Program Chair of the AAAP.  Next year will mark his 50^th year as a club member.  His civic activities include presently serving on the West Windsor Township Zoning Board of Adjustment.  He is married and has three children and six grandchildren.

Using Zoom: While we are, social distancing the AAAP Board has chosen to use Zoom for our meetings, based our belief that many members have already have used Zoom and its ease of learning. One of its great features is you can choose whether you want to install the software on your computer or use it within your browser.

How to Join the January Meeting: For the meeting, we are going to follow a simple two-step process:

1. Please make sure you have Zoom installed on your computer. You do not need a Zoom account or need to create one to join the meeting. Nor are you required to use a webcam.
2. Please visit our website for the link to the meeting

NOTE: We plan to open the meeting site 30 minutes to the 7:30 start time. This way you won’t have to rush to join the meeting. A maximum of 100 attendees can join the meeting.

More Information: The Zoom site has many training videos most are for people who are hosting a meeting. If you’re unsure how Zoom works you might want to view the videos on how to join a meeting or how to check your computer’s audio and video before the meeting.

January’s Journal Club Presentation: Bob Vanderbei will kick off the new year’s Journal Club presentations by showing some of his excellent and timely astrophotos and explaining how he accomplished them. In addition, Bill Murray will tell the story of Project Diana, in which a small local team of radar experts first probed a celestial body by bouncing radio pulses off the moon, 75 years plus two days ago.

We hope to make these short presentations a regular feature of our monthly meetings. If you are interested in presenting a topic of interest, please contact either director@princetonastronomy.org or program@princetonastronomy.org. We’d like to keep our momentum going!

Upcoming Programs: Here’s a look ahead at upcoming guest speakers. We’re expecting to conduct virtual meetings for the remainder of this academic year. In an effort to turn necessity into a virtue, we’re casting our recruiting net a bit wider than usual, inviting speakers for whom a visit to Princeton would be impractical or inconvenient. Suggestions for guest speakers for September, 2021 and beyond are welcome.

February 9  – Guömundur Kári Stefánsson: Dr. Stefánsson is the Henry Norris Russell Fellow in Princeton’s Department of Astrophysical Sciences. He will speak on innovative techniques he has helped develop for Detecting and Characterizing Exoplanets.

March 9 – Keivan Stassun: Prof. Stassun is the Stevenson Professor of Astrophysics at Vanderbilt University. He will describe The Life and Death of Stars, the title of a course he delivered for The Learning Company.      

May 11 – Alexandra Kroll Davatzes: Prof. Davatzes is an Associate Professor at Temple University. Her talk will describe Precambrian Meteor Impacts and Implications for Early Earth.

May 11 – Alex Hayes: Prof. Hayes is an Associate Professor of Astronomy at Cornell University and Director of its Spacecraft Planetary Image Facility. He will speak on Ocean Worlds of the Outer Solar System, plus he will give a brief report on the Mars 2020 mission.

June 8 – Anna Schauer: Dr. Schauer, a new mother, is the NASA Hubble Fellow at the University of Texas at Austin. She leads the team researching what she’s nicknamed the Ultimately Large Telescope, a lunar liquid-mirror telescope that will aim at investigating First Star Formation.

End of an Era: For more than five years, we have all benefitted from Ira’s efforts in recruiting an impressive array of interesting guest speakers. Their expertise and scholarship, often on the cutting edge of astronomical research, are a defining characteristic of this club. Ira took on a vital role, and he did it very well. As they say in showbiz, he’s a tough act to follow. As Ira transitions from Program Chair to Active Member, I want to express my gratitude to him not only for his past contributions, but also for generously sharing his information, experience, and advice with his successor (i.e. me). Through his judgment and thoughtfulness, I am confident of a graceful and seamless transfer of power.  Thanks also to Bill Thomas, who contributes research and advice to help identify topics and presenters. I’m thankful and relieved to have Bill’s and Ira’s help.

Though I’m officially taking over as Program Chair, Ira will still be quite visible as Zoom maven, and of course as an active member of AAAP. He can be reached at ipolans@princetonastronomy.org.

Looking forward to you joining us on Zoom at the January meeting!