Outreach Wrapup

by Gene Allen, Outreach Chair

It has been an amazing year. If it had not been so frantic at times, better records would have yielded better summary data. Some details may yet be recaptured from emails. It would have been nice to be able to report the total number of members who were involved, or the count of the number of times each of our volunteers stepped up, or the total number of guests served. We do have a general inability to count the number of visitors to the Observatory on a Friday night, because of all the comings and goings. Counting attendees is similarly difficult when one is involved with making a presentation or guiding them at the eyepiece.

It is safe to say this was a record year for Outreach at the AAAP. My email chains were dropped into folders corresponding to each event, so that list provides some accounting. Coordination was completed, and members volunteered to support some 35 events. They consist of remote events and groups that arranged to come to Simpson, either on a scheduled Public Night or a special opening. Not all took place, because of weather or cancellation by the customer. That does not discount the effort that went into scheduling and recruiting, or whatever effort it took on the part of those who committed to help. Hearty thanks to all of you who responded to my repeated appeals.

Here is my list of event email folders. If I take the time some rainy or snowy day to attempt to consolidate what records do exist, perhaps this reporting can be expanded. For now, this is what is available:

190203BelleMead 190226Stuart 190308Plainsboro
190322Hopewell 190322Hopewell 190405Simpson
190428Communiversity 190510Simpson 190517Simpson
190531Simpson 190601Simpson 190608Simpson
190620Simpson 190621Simpson 190709Lambertville
190720Planetarium 190720Simpson 190724LIB-Hickory
190725LIB-Cranbury 190725Morven 190803GravityHill
190807MtnLakes 190810LIB-Plainsboro 190812LIB-OldBridge
190822LIB-Hollowbrook 190823Simpson 190831WCSP
190904LIB-HopewellPublic 190914RosedaleLHT 190920Simpson
190927Simpson 190928GravityHill 191004Simpson
191018Simpson 191019Simpson 191090LIB-Pennington
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Minutes of the October 8, 2019 AAAP General Meeting

by John Miller, Secretary

Assistant Director Larry Kane opened the meeting at 7:30 p.m. AAAP overview and upcoming events schedule were discussed. Prasad Ganti then introduced the guest lecturer – member John Church

  • Larry reminded the group about the upcoming Monday, November 11th Mercury transit. Plans are to have the observatory operational and members and guests can bring their own solar equipment. Bill Murrary mentioned the sun will be obstructed until about 9 a.m.
  • Larry mentioned interest in the InfoAge Science facility located in Belmar, NJ. This includes and operational radio telescope refurbished in 2016 by the Princeton University Physics Department
  • Review discussions were led by David and Jen Skitt regarding contractor reviews and other topics for the observatory structural upgrades. Treasurer Michael Mitrano is working on contractor contact
  • Treasurer Michael Mitrano reported, in absentia, the club’s current cash balance was $15.6 K.
  • Larry adjourned the meeting about 9:45 p.m.
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Mercury Transit at the Observatory on November 11, 2019

This gallery contains 7 photos.

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Cosmology and Exoplanets

by Prasad Ganti

The Nobel prize in Physics for 2019 was announced for two separate advances. One was for Cosmology which moulded our view of the Universe over the last five decades. The second advance was the discovery of planets outside of our Solar system. Both of these advances have expanded our ideas of the Universe much beyond our Solar system, far out into the distant galaxies and far back into the time of the birth of the Universe itself.

Expansion of the Universe was confirmed by Edwin Hubble closer to the mid twentieth century. That is each galaxy is moving away from every other galaxy. Further away the galaxy is, faster it is moving away. Playing this story in reverse, leads to a point in time when the Universe was born. It is called the moment of the Big Bang. It sprouted forth from a tiny point with incredible amount of energy about 13.8 billion years ago. And suddenly expanded in a fraction of a second (called inflation) to a big space where the temperatures cooled down considerably enabling the creation of radiation (like light) and atoms, leading to formation of Hydrogen and Helium. Stars formed in due course and eventually galaxies.

Such a framework of the Cosmos was being constructed by several luminaries. One of them was James Peebles of Princeton, New Jersey, who was awarded this year’s Nobel prize. Peebles realized that the temperature of this background radiation, called CMB (Cosmic Microwave Background), could provide clues about the Big Bang and confirm its happening. This background radiation is omnipresent and is seemingly uniform in all directions as viewed from the Earth. The hunt for such a radiation was on. In stepped Bob Wilson and Arnos Penzias, two radio engineers from AT&T Bell Labs in New Jersey. They accidentally stumbled upon the background radiation while testing microwave antennas. They found the “noise” whichever direction the antenna was tilted. It could not go away with any amount of tweaking of the antenna. The noise manifests itself in form of random dots seen on a TV channel which is not receiving any signal. Penzias and Wilson were looking for an explanation and reached out to Princeton University where Peebels and team were very happy to connect and exchange notes. Each side got what they were looking for. The Big Bang theory was put on a firm foundation.

Another aspect of the background radiation is that Peebles thought that some amount of tiny non-uniformity must have been present to enable the formation of stars and galaxies. It is not the same in all the directions all the time. Tiny microscopic fluctuations must be present. Such measurements needed very high level of precision. Confirmation came from the COBE satellite (COsmic Background Explorer leading to Nobel prizes for John Mather and George Smoot in 2006), later from the satellites WMAP (Wilkinson Microwave Anisotropy Probe) and Planck.

Peebles also thought about the energy of empty space, which eventually came to be know as dark energy. Dark energy remained just a theory for fourteen years, until the universe’s accelerating expansion was discovered in 1998 (leading to a Nobel Prize in Physics 2011 to Saul Perlmutter, Brian Schmidt and Adam Riess).

Second part of the Nobel prize was awarded to Michel Mayor and Didier Queloz who found the first planet outside of our Solar system. Stars in our Milky Way galaxy are relatively easier to find as they emit sharp points of light. Other galaxies are seen as blurs of light as they contain a collection of stars. But planets orbiting other stars are very difficult to find. They do not emit any light, instead just reflect the light of its star. This reflected light is nearly impossible to detect.

The planet pulls on the star as much as the star pulls the planet towards itself. The tug of the planet on the star is small. As a result of this tug, the light coming from the star is doppler shifted, that it is blue shifted when the star moves towards us and red shifted when the star is moving away from us. The doppler shift tells us how long the planet takes to go around the star and how heavy the planet is. To detect this light, a very sensitive spectrograph is required. Also, as the planet moves in front of the star, the amount of light reaching us reduces. Known as transit photometry, it provides the size of the exoplanet. The size and mass of the planet leads to knowing the density and in determining its structure, if it is a rocky place or full of gas.

Mayor and Queloz found the planet labelled as 51 Pegasis b, which moves rapidly around its star 51 Pegasis, which is fifty light years from the Earth. It takes four days to complete its orbit. Only eight million kilometers (comparatively Earth is 150 million kilometers from the Sun) from it, the star heats the planet to more than a thousand degrees centigrade. The planet is a gaseous ball, similar to our Jupiter. To date, close to four thousand planets have been found, but Mayor and Queloz remain the harbingers of this quest.

A lot has been learnt about our Universe and the distant stars and planets in the last few decades. And very appropriately, recognition came in form of a Nobel prize, the highest honor awarded by mankind.

Posted in November 2019, Sidereal Times | Tagged | Leave a comment

white dwarf – black hole

by Theodore Frimet

oh my!

Ok. I’ll take what I can get. It is a dangerous thing to shout out a Hypothesis. Especially when professional scientists are doing the math, and writing their journal entries. And then you find a match! Ok, maybe this is a Sheldon moment. Not to be outdone, by this beloved member of the Big Bang Theory, I read the ensuing article. I chased down a few of the citations from the dusty, dank corridors of the WWW. Coughing up the dust, from this proverbial library, I find Russian literature that was previously hidden from my sight.

In the August 6, 2019 essay, “Planetary Nebula”, I chastised myself for being unable to source citations. My bridge forming relativistic electron scaffold, streaming from an active black hole, was not to be found. I couldn’t make the stream culpable for forming the matrix upon which white dwarfs caste their nebulae upon.

Within the reach of this Amateur, we were hopelessly entrenched with binary stars in the formation of Planetary Nebula. I discussed how those systems had long discarded their gas. They had left their binary partner, a White Dwarf, naked and alone.

Thru an online lecture, I learned to appreciate complementary light spectrums, and how they indicated the presence of binary stars, in nebulae local parentis. I finally alluded in closing, to complementary light spectrums, and periodicity of the light curve. “Perhaps where there is no light, there is only a hole. Look closely and find periods, with no complementary light spectrum, sans the ever present White Dwarf.”

I can now be a bit braver, and no longer hide in prose. Black holes are x-ray emitters and can be detected with x-ray telescopes. When Black Holes are quiet, they do not emit x-rays, and are not detectable. However, they can be detected if gravitationally bound to the White Dwarf. The dwarfs periodicity can be measured – either by occultation light data, or by alteration in her orbital data.

Kevin T Smith, writes the report on “A noninteracting low-mass black hole – giant star binary system”, (Science 01 Nov 2019: Vol. 366, Issue 6465, pp. 637-640 DOI: 10.1126/science.aau4005), writes about a 2.6 solar mass object that emits no light, including x-rays. Combining radial velocity and photometrics demonstrates that the massive star is in a binary system, paired with a black hole.

What led me to chuckle, were two references that I had long sought out. They were hiding in the Harvard repositories. This is the quote (Smith, et al) that brought me to their doorstep:

“Quiescent noninteracting black hole stellar binaries have not been found in radial velocity searches, although the existence of such systems has been discussed for decades (10, 11).”

(10) O. K. Guseinov, Y. B. Zel’dovich, Collapsed stars in binary systems. Sov. Astron. 10, 251 (1966). Google Scholar

(11) V. L. Trimble, K. S. Thorne, Spectroscopic binaries and collapsed stars. Astrophys. J. 156, 1013 (1969). doi:10.1086/150032 CrossRefGoogle Scholar

I gingerly keyed into the citation, numbered 10. The original article was submitted October 18, 1965. The Journal hailed from Soviet Astronomy, Vol. 10, p251. It discusses detection of collapsed stars, which are members of spectroscopic binaries.

I hold my breath, as I click on citation, numbered 11. In the abstract, I find, “the absence of a secondary spectrum in these systems, could, in principle, result from the secondary star’s being either a collapsed star or a massive neutron star.”

Although Einstein predicted black holes in 1916, the term “black hole” wasn’t coined until John Wheeler did so in 1967. So there are two caveats, here. In the citation, there is no mention of a black hole, only “collapsed stars”. And secondarily, the author appears uncomfortable with the lack of x-ray emissions. Reading further, they discard unseen companions that are less than the Chandrasekhar limit, and declare the unseen companion as a white dwarf. They back-reference to Zel’dovich & Guseinov, where discovery of x-rays or gamma-rays, “would constitute evidence for the presence of a collapsed star or neutron-star secondary.”

I remain comfortable in my wheel-house this morning. I add to the mix, from August’s essay, that nebular gas, structured upon relativistic outflow of electrons, and in many cases, no longer appearing present among the many nascent white dwarfs, have had their gaseous orbs and out-layers, gobbled up, long ago, by their unseen partner, a black hole. No Watson. No Holmes. Just sheer dumb luck.

Posted in November 2019, Sidereal Times | Tagged | Leave a comment

The Einstein Cross

by Theodore R. Frimet

How to measure a Gravitational Lens

The daily commute to backfill, in Norristown, sometimes has me waiting in the off-ramp. Car is idle, and I spy a bird on the left shoulder. She sits atop a tree. Looks like a bad version of a Blue Spruce. Not the bird, the tree. I wonder at her, as she lofts from the tree, and off into the brush, nearer to my gas guzzling, carbon spewing, iron chariot. Ok, not so much a guzzler. Sure, there is a carbon footprint – yet my car is mostly light steel, aluminum and plastic. The bird flies away. Ironic.

You’ve read the preamble, and you are confused. So am I. How did this experience ever spew intelligence onto the light bending affects of gravitational lensing? I dunno. No clue.

Here is what did follow, as I stepped onto the accelerator;

[which by now you should all know that this isn’t your fathers gas pedal – it is a link to actuate, via micro-controller, your mass flow air sensors, and aggregate accoutrements.]

was a brief time foray into a meager graphic analysis of how I could measure density differences of a gravitational lens.

Here it is briefly. It is brief because I choose not to augment my mind-scape with mathematics. I leave that to you, all. Calculus, anyone? Ok. My bad. It is simply because I can’t possibly drink another cup of coffee, without offending someone, or something. Sigh. I could probably use a dose of polynomial mathematics, where each band of the Cross is represented by a separate variable and coefficient – and the answer is the total mass of the lens. “What?” – Lil John.

Borrow, beg or steal three Hubble images. They need to be representative of a gravitational lensing effect. No time? No worries. I’ve done this for you in a past essay. We’ll repost the three images. Here is the link: Ring Around The Rosies

Caveat Emptor. I dug these out on my own, and they aren’t the BEST images of gravitational lensing effects, ever. Whomsoever, they will do. ‘That’ll do, pig. That’ll do.’

The best ever would show an Einstein Cross. So, for now, use your imagination. Take the composite image, and put it into a graphics program. Or print it out, in full color, and put it onto the table before you. No matter. (Hey, maybe that’s a pun- ‘no matter’ – hehe).

Construct a Cartesian plane onto your image. You know? Four quadrants. Cool beans. Find a matching element, from one of the mirror image galaxies, that was smeared across the page. Measure it, coordinate – to – matching coordinate. You are going to see if there was any subtle movement, in any mirror image.

Or more easily enough, look at my composite. I have stacked three Grayscale images, and enabled them as RED, GREEN and BLUE, in a graphics program. They appear to you, in the above link, as ‘black and white’, separately, and color (RGB) when combined. Where-ever you find subtle color shifts, in different quadrants, please know that the grayscale values shifted, over time. Remember that each image used in the composite was taken at a different time. You would imagine that there would be shift in the image. However, I would expect that each mirror image would shift the same. It does not. Did it? You tell me. After all, it’s your Universe.

In an Einstein Cross, the images that swirl, up and down, left and right, have some variance in position. If you deconstruct the images, and their effect, perhaps by means of a reverse-Gaussian algorithm, you might come to one of two of my conclusions. Either space-time was severely constrained, or warped, differently in each of the quadrants. Or the massive galaxies that make up the galactic lens have an obvious geometry and structure that can be recreated by studying an Einstein Cross’.

Yes, the geometry and structure of the massive galaxies warp space-time, and create the lens. Yes, I think that you can at the very least, know which quadrant has a more “dense” allocation of gravity bending space-time matter. Above we hint at the structure, and function of what is behind the eye of this Cosmological Camera obscura.

If you have access to more advanced channels of Cosmology, may I recommend a cup of Quasars, detected in the background, and to meter the differences in their absorption spectrum? This notion, I must admit, was borrowed from the article, “Gas filaments of the cosmic web located around active galaxies in a protocluster”, Science, 4 October 2019, Col 366, Issue 6461, pp 97-100.

Posted in November 2019, Sidereal Times | Tagged | Leave a comment

The Milner Experiment

by Theodore R. Frimet

Ok. I am going to actually write about the Milgram Experiment (2). That was where volunteers gave shocks to people. The shocks were make-believe, and the persons receiving the shocks faked their pain and suffering. A high number of participants shocked the subjects, despite the apparent visual suffering. And to Milgram’s surprise, the increase shock level would have killed a participant; yet the volunteer continued to deliver the fatal dose. Some, as they left the center, never inquired as to the health or welfare of those they acted on. Milgram discovered a persons intent to follow authority, without question.

Without realizing it, somehow I have connected the dots between Nazi Germany, California’s early Eugenics program in denying the Deaf their reproductive rights (3), and people that write hurtful, and lasting social imprints on the World Wide Web. The first resulted in the deaths of millions, while the second was the progenitor of Shoah. I wait with baited breathe as to the outcome of the Third. Perhaps societal participants writing on the wall, with impunity, is not what it seems to be.

With minds not yet fully developed until the age of 21, the brain simply cannot distinguish between reality and fantasy. An adult watches a movie, and your brain transcends you from your chair, to the scene. A child reads a negative post, and is transfixed into a self-harming relationship. They have been baited with your breath. I regret to discuss the outcome of your make-believe Milgram shock.

When we write comments on the performances of others, in a service industry, we can be blunt. Not everyone has the talent of tongue, these days. Most write three or fewer sentences to ascribe their wonder, or blatant dissatisfaction. However, now, in this brief pause between the pauses, I am in dismay. I attribute this to both the public’s fractured memory and the proclivity of the few to practice harmful graffiti.

When you write negatively, be gentle not only with your target audience – be gentle with yourself. Because all the while; all that you experience – your sight, sound, taste, and thoughts, are all recreations in your mindset. Yes. It is an argument that you have with your own ethos. The model that you create is simply yourself. You walk blind in the Universe. Nothing is out there. It is all inside your head.

If you have read up-to-this point, perhaps now you are ready for a new truth. That the lists of ideological mis-steps that you believe in, do order themselves to cause harm to others. The social queues that appear to be unrelated are part of a fuzzy logic system. Simply because the interdependent players remain invisible to you, does not in any way blunt the edge of the knife. When one part of a system is stressed, it will affect the whole. Your practice of leaving behind a curt comment, is only you whetting the edge of a realm where you believe there is absence of malice.

However, I mis-speak. You have decided to not go on. You could continue. The experiment may have required that. It may have been absolutely necessary, and you would have had no other choice. So said, Milgram. You have only written once on the wall. Yet the difference between the Milgram experiment and your licentiousness, is that one act was fleeting; while all the while your participation in a social experiment continues on, day-after-day. Forgive me for being the one that reminds the few – that your practice here, is the undoing of teenagers, everywhere. For you have caste the mold where all learn how to write. Nestled in your brief grammatical structure are the implements of where young minds go to their demise.

Wherefore art thou, Astronomy? He said twice, “I was in a car accident”. I pretended not to hear. I wanted to make sure I delivered the Dob, and beat the rain. It was going to rain. It always clouds in, during an Astronomy event. Why would the conclusion of a sale be any different?

For the past few weeks, I had posted my offer for the great behemoth. Hundreds looked, dozens watched. Several had offered. Many were refused. Of course, all were kicked to the curb, until the last offer. It wasn’t low, and it wasn’t high. It wasn’t even middle of the row. The price was simply right. I accepted. This sale was pre-empted for local pick-up, no delivery. Upon payment, I contacted the buyer. They were busy that afternoon.

Time is a precious thing. Weather can make it more valuable. I needed to look between the clouds, and focus on the light that I could see. Later it would rain. Tomorrow it would certainly be wet. Now is the time. I said, “let me come out to you”. We agreed. An hour later I waited in a driveway, Dob in SUV. Movement. Transfer. New telescope in another home. Nestled under the tree, perhaps? Not really. It isn’t Christmas. Heck, it isn’t Chanukah or Kwanzaa, either.

I am now in the present. The Universe reaches out and taps me on the shoulder this rainy, Sunday morning. It does so with impunity and anonymity. Let’s You and I put away the lazy Susan, and spin a yarn on a crises. Synthetic opioids. Many have the same story. We are truly embedded. It is my time to read the writing on the wall. I am hopeful that I am not succoring to a Milgram experiment. I could list off what I knew of synthetic opioids. I ask you, “what do you know”?

Visit the CDC website and read more about Brenda, Cortney, Devin, Judy, Katie, Mike, Noah, and more. The song remains the same.

The CDC site triggers a memory. A dear friend had committed suicide. So they said. Her fentanyl patch had ruptured. Later we learned that these patches were defective, delivering a fatal dose. I parlayed the story, and suggested that they contact a lawyer. Perhaps there is a class action lawsuit to participate in? A lawyer would know. Always best to send a friend to a doctor who knows best. Or in this case a Juris Doctor.

I will not know the outcome of the story. Not ever. Few are the words that are written on the wall. There is no Milgram participant here to give a shock. My only hope is that all of you, will continue to keep to your ethics. As Amateur Astronomers, as you come out of your seclusion to interact with the public, all I ask is that you too, do not go gently into that dark night.

References

  1. Milner – Please read about Brenda Milner’s 1952 research, last accessed on Sunday, October 27, 2019 at 10:43 AM EST:
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2649674/
  2. Milgram – Please read about Milgram’s experiment, last accessed (per tempus) https://en.wikipedia.org/wiki/Milgram_experiment
  3. “Chapter 84.” For Hearing People Only: Answers to Some of the Most Commonly Asked Questions about the Deaf Community, Its Culture, and the “Deaf Reality”, by Matthew S. Moore and Linda Levitan, Deaf Life Press, 2016, pp. 545–554.
Posted in November 2019, Sidereal Times | Tagged | Leave a comment

Snippets

compiled by Arlene & David Kaplan

-BBC

Nobel physics prize
Three scientists have been awarded the 2019 Nobel Prize in Physics for “ground-breaking” discoveries about the Universe. James Peebles, Michel Mayor and Didier Queloz were announced as this year’s winners at a ceremony in Stockholm. The winners will share the prize money of nine million kronor (£738,000)…more

-Carnegie Institution For Science

Saturn overtakes Jupiter as planet with most moons
Jupiter had been the “moon king” for some 20 years. Saturn has overtaken Jupiter as the planet with the most moons, according to US researchers. The moons were discovered using the Subaru telescope on Maunakea, Hawaii. Dr Sheppard told BBC News that Jupiter had been the planet with most known moons since the late 1990s…more

-BBC

Milky Way explosion detected
The Hubble observatory has found evidence of a cataclysmic flare that punched its way out of our galaxy about 3.5 million years ago. A massive burst of ionising radiation exploded from our galaxy’s heart. The impact was felt 200,000 light-years away. The discovery that the Milky Way’s centre was more dynamic than previously…more

-TAS

‘dark Universe’ makes progress
Europe’s space mission to uncover the secrets of the “dark Universe” has reached a key milestone. The test model of the Euclid telescope has just emerged from a chamber where it was subjected to the kind of conditions experienced in orbit…more

NASA engineer invents physics-breaking new space engine
Star Trek’s Montgomery Scott famously said “ye cannot change the laws of physics”, but a real-life space engineer says he might have just done that. David Burns of NASA’s Marshall Space Flight Center in Alabama has unveiled what he’s calling the ‘helical engine’, which could potentially power flights across space without using any fuel at all…more

Posted in November 2019, Sidereal Times | Tagged | Leave a comment

From the Director

Rex

 

 

 

by Rex Parker, Phd director@princetonastronomy.org

Speakers for Astronomy

Our guest speaker at the October 8 meeting will be John Church, PhD. John is a former Director and longtime member of AAAP. See Ira’s article below for information about this presentation. Have you considered giving a 10-minute member talk following the intermission at an upcoming meeting? This is a great way for members to get to know each other and share experiences in the club – tales of recent astronomy life, perhaps a book or travel review, observing tips, a new telescope, slides optional. Please contact me or Program Chair Ira Polans to get onto the schedule for an upcoming meeting.

Saturday Night Fever

The AI running the weather program didn’t do us any favors on Sat, Sept 28, and we cancelled the Gravity Hill Star Party. However we really want to develop a tradition of member Saturday nights with telescopes. The potential benefit of this came out in the recent member survey, where 62 of 80 responders said they own a telescope but only 37 use it once in a while or more often. Becoming more skilled with telescopes is important to 67 yet only 38 are able to take advantage of using the AAAP Observatory more than once a year.

We encourage members to set up telescopes on clear nights at the west end of the soccer fields at Washington Crossing State Park. This secure location has wide views of the sky and is easily accessed off Rte 579/Bear Tavern Rd on the way to the Observatory and through much of the year no gate opening is needed. After soccer seasons ends in November the front gate at Bear Tavern Rd may be locked, but AAAP KeyHolders can open the lock.

To start out, let’s initiate Saturday night telescope sessions with members as follows (beginning October 19):

  • Send an e-mail to me by noon on Saturdays
  • Include “telescope” in your e-mail subject line
  • In your note, mention the time, expected duration, and what telescope you’d bring
  • I’ll broadcast an e-mail note to the membership that day

Big Improvements in Video Astronomy

Plans are underway to mount the club’s ZWO-ASI294 color CMOS camera onto the Celestron-14. This would replace the function of the Ultrastar color CCD camera currently on the 5-inch refractor and allow eyepiece use with the refractor to give a wide/rich-field view alongside the C-14. Importantly, the smaller, lighter, and easier to use Ultrastar would become available for members to use in outreach.

The ZWO is a technological marvel which illustrates why CMOS sensor technology is displacing the CCD in astronomy applications. This month we acquired the hardware needed for the ZWO camera to be mated to the Celestron-14, a Meade model 647 2” flip mirror assembly allowing users to flip back and forth between eyepiece glass and camera video. A focal reducer was added to widen the field of view. The picture below, from a work session at the Observatory with Tom Swords and David and Jennifer Skitt, shows the setup we hope to install after the current public Friday night season is over.

Configuration of the ZWO-294 camera on the C-14 with Meade flip mirror (see text).

Posted in October 2019, Sidereal Times | Tagged , | Leave a comment

From the Program Chair

by Ira Polans

The October meeting of the AAAP will be held on the 8th at 7:30 PM in the auditorium of Peyton Hall on the Princeton University campus. The talk is When Ireland Was the Center of the Universe by long time club member John Church.

In the late 1840’s, William Parsons, the 3rd Earl of Rosse, constructed and mounted a 72-inch aperture Newtonian reflecting telescope in central Ireland. Remarkably, this was to remain the largest telescope in the world until the 100-inch Hooker telescope was placed in service in 1917 on Mt. Wilson in California.

Parsons was the first to see and depict the spiral structure of an exterior galaxy, M51 or the Whirlpool Galaxy, in the constellation of Canes Venatici near the tail of Ursa Major. He used his telescope to examine many other galaxies and objects as well. His drawing of M1, the supernova remnant in Taurus, led to its being named the Crab nebula.

In the mid 1800’s, telescope mirrors were made of speculum metal, an alloy of 3 parts of copper and 1 part of tin. Parsons needed several tries to finally get satisfactory blanks. He designed and made his own large steam-powered machine to grind and polish the nearly 3-ton mirrors. He made two of them so that when one was being re-polished, the telescope could still be used.

Mounting such a mirror in a movable tube was a major engineering project. An equatorial mounting was out of the question, so Parsons designed and constructed a huge alt-azimuth mounting between two 40-foot high masonry walls. This allowed the 12-ton telescope assembly to swing a few degrees out of the meridian each way and observe a large arc of sky. Slow-motion controls were provided for both altitude and azimuth.

Access to the eyepiece can be a major issue even with small Newtonians. Parsons solved this problem with an elaborate array of movable galleries mounted on the western masonry wall Several assistants were needed at every observing session to raise and lower the assembly and move the galleries.

Our speaker, John Church, visited the Rosse estate in 2004 after he and his wife had attended a family wedding on the west coast of Ireland. The castle, which is the home of the present Earl, dates from about 1620. The estate also contains a fine arboretum and other attractions including the I-LOFAR (Irish Low Frequency Array) radio telescope installed in 2017, the westernmost of 50 such stations.

Two changes are being made for the 10 minute talks this season. First, the talk will be given after the intermission. Second, we are instituting a 10 minute limit. Since we want to keep the talks to 10 minutes, the speaker will be given a 90 second warning to wrap up the talk. If you’re interested in giving a 10 minute talk for our October meeting please contact Larry at assist.director@princetonastronomhy.org. Or if you’re thinking about giving a talk later in the year please contact either Rex or me.

There will not be a meet the speaker dinner prior to the meeting.

Finally I will not be able to join you at the meeting but think the talk will be interesting! See you in November.

Posted in October 2019, Sidereal Times | Tagged , | Leave a comment