Amateur Astronomers Association of Princeton

by Rex Parker, Phd director@princetonastronomy.org

Zooming AAAP Meetings this Fall.
It’s no surprise that we won’t have access to Peyton Hall auditorium in the near future, so we’ll be patient and go with Zoom this fall. Our May and June zooming experiments mostly succeeded, for example we were able to do formal membership voting for the Board and for a Capital Expenditure. We had about 55 members participating both times and it all seemed to go reasonably smoothly. Speaking of members, our ranks have increased by 11 since July putting us around 120 members total.

It hasn’t escaped notice that the migration to virtual meetings unleashed some of the bounds of space for getting guest speakers. Recently the Board entertained ideas of bringing in distant big name speakers for new topics. While Ira is working on that, we would like to hear your suggestions for speakers or topics from the next year. Right now the sky’s the limit!

The Board also decided this summer that we will make our monthly Zoom meetings open to the public, since our meetings with guest speakers have always been open to the public. This means we’ll all need to cooperate and be patient during the Zoom sessions to ensure they remain courteous, coherent, and enjoyable for all.

Unveiling AAAP Video Productions!
Accepting that we’re stuck in this virtual world for a while, let’s think about ways to connect with each other as members. Beyond the guest lectures at meetings, which tend to focus on deep science topics, there seems to be a gap (aka “opportunity”) in ability to share favorite astronomy ideas and “how-to” information and stories with each other. This is especially so with the current restricted access to the Observatory, our favorite gathering place for hands-on astronomy. We propose new approaches to bring members together, shining a light on experiences with telescopes and astro-technology and sharing other celestial insights. The idea has taken form: let’s use video technology to create “how-to” and AAAP-relevant content for members. This is not to compete with the Mount Palomars of the world, rather it is for members to learn and get to know others in the club. I’d like to credit member Rich Sherman, an expert videographer, for proposing the idea and running the first video shoots/interviews. The initial “guinea pigs” were me and Bill Murray, with John Miller and Dave Skitt in the queue. The featured videos are being posted on the website under the Club Astrophotography tab. We’re hoping more members will step up to record video sessions – if you’re interested please send me a note and let’s discuss setting it up.

Update on Observatory Repairs and Opening.
The resolution authorizing $9500 for observatory repair passed at the June 09 meeting by unanimous vote (43 yes). We’re in the process of getting State administrative approval of the construction plan, and still hold out hope of scheduling this fall with the contractor.
Meanwhile, the Observatory is closed to the public right now. But it is open to AAAP Keyholders, who must pre-schedule with the Observatory Chair (observatory@princetonastronomy.org) before going out there, so we can keep tabs on the restricted numbers allowed out there. Anyone at the Observatory grounds or building at WC State Park must wear a mask and practice social distancing. Other members can also go to the Observatory so long as the number limits are not exceeded, but you’ll need to be with a Keyholder – inquiries should be directed to the above e-mail.

Seeking Volunteer for Co-Editor of Sidereal Times.
We are seeking a member with the “right stuff” to help edit and produce content provided by members as Sidereal Times co-editor, along with editor Surabhi Agarwal (who also serves as AAAP web-master). Experience with WordPress is a plus but “on-the-job” training is a great way to learn. Because of its status as official publication of the AAAP, and given our internet visibility, this is a very important position in the club. Please send me and/or Surabhi a note if you’re interested (director@princetonastronomy.org; editors@princetonastronomy.org).

From Comet to Gas Giant in a Single Night!
In this seemingly endless summer a couple of celestial events have popped up to vie for our attention, a welcome distraction from other news that need not be mentioned here. The splendid comet designated C/2020 F3 NEOWISE (an acronym for Near-Earth Object Wide-field Infrared Survey Explorer, the NASA space telescope that discovered it) transitioned from pre-dawn to after sunset in July and ascended the early evening sky under the bowl of the Big Dipper.

As alluring as the comet was, two other celestial wonders have made their presence known in the southern sky in early evening. A smart phone astronomy app would be one way to quickly find these planets, and they are bright enough that they stand out even in our light pollution compromised skies. The great Jovian planets Jupiter and Saturn – gas giants! – both reached opposition in late July. That’s when they’re at their closest position to earth in their orbits, which happens once a year due to earth’s orbit. Jupiter and Saturn themselves have orbital periods of 10 and 11 earth-years. This is also why they transit a little before midnight now, meaning that they reach their highest altitude in the sky and cross the celestial meridian before midnight (the meridian is the line joining both poles with the zenith point). In addition you’ll notice Jupiter and Saturn have reached their brightest, with magnitudes ~ -2.7 and 0.1, respectively. In fact Jupiter is brighter than any star or planet in our skies, except Venus when it is at the far side of the sun relative to earth. Recall that the magnitude unit is a scale worked out centuries ago, with the brightest to dimmest stars seen by naked eye ranging from magnitude 1 to 6, each magnitude number being 2.5 times brighter than the next so that 6 magnitudes spans ~100-fold difference in brightness.

Both Jupiter and Saturn are great sights if you’re lucky to have a small telescope. In fact both show surprising detail even with binoculars if held steadily enough. For instance, you can see the 4 Galilean moons of Jupiter, discovered by Galileo himself in 1609 using a small telescope, which had been recently invented. Notice how the positions of the 4 moons relative to each other and the planet change, even in the course of a couple hours in the same evening. If you had a big enough telescope to see the details of the surface of Jupiter you’d notice the surface changing in the span of a few hours as well. Amazingly, Jupiter rotates on its axis once every ~10 hours! Under good conditions you will notice the “stripes”, prominent bands of different shades of yellow in the hydrogen atmosphere. There is also the famous Great Red Spot, a violent storm that has been observed on Jupiter for over 300 years and can be seen under very good seeing conditions in a small scope.

A few degrees to the left (east) of Jupiter you’ll see Saturn, brighter than other stars in the sky at this time, though much dimmer than Jupiter because it is twice as far away. Imagine the line between them. This is an arc along the ecliptic, the plane in which all the planets’ orbits lie. (Except Pluto, one of the reasons it was demoted from planet status a few years ago). Saturn’s rings are visible in binoculars and especially pronounced in even a small telescope. Galileo was the first to see Saturn’s rings, though he thought they were moons on either side of the planet. The rings are actually made up of solid material, largely water ice, aggregated over millennia into discs around the planet due to Saturn’s immense gravity and dynamics. Their angle of inclination, or tilt, toward earth changes in the course of its orbit around the sun. While viewing Saturn that other bright point of light you may see in the scope is Saturn’s largest moon Titan. Well-named, as it’s the largest moon in our solar system, Titan was once hypothesized to be a possible place for life, though the current thinking is that this is highly unlikely and that it is an inhospitable place, suitable for science-fiction scenes but not likely biological ones.

The photos below were taken from my back yard in Titusville using a 5” refracting telescope with 5X Powermate (giving focal ratio f/40 and focal length 5000 mm) and using an SBIG ST-10 astronomy CCD camera. If you’re interested in learning more about astrophotography check out the new “how-to” videos being posted on this AAAP website (discussed above), and visit my own astrophotography website featuring New Jersey-based imaging at www.rexparkerpixels.com. Feel free to send me a note if you want to talk about the various approaches to astrophotgraphy and astrovideo.