The Gloucester Area Astronomy Club

A Great Conjunction, and the Christmas Star

By David H. Levy.

Said the night wind to the little lamb:
"Do you see what I see?
Way up in the sky, little lamb
Do you see what I see?
A star, a star, dancing in the night
With a tail as big as a kite
With a tail as big as a kite"

                   Noel Regney and Gloria Shayne, 1962

 In the words of this beautiful Christmas carol,written during the Cuban missile crisis of 1962, we are reminded of Christmas, the biblical Book of Matthew, and the Star of Bethlehem.  Famous as it is, this story appears but once in the Gospel according to Matthew::

Now when Jesus was born in Bethlehem of Judea in the days of Herod the king, behold, wise men from the East came to Jerusalem, saying,

 “Where is he who has been born king of the Jews? For we have seen his star in the East, and have come to worship him.”

 When they had heard the king they went their way; and lo, the star which they had seen in the East went before them, till it came to rest over the place where the child was. 

When they saw the star, they rejoiced exceedingly with great joy;  and going into the house they saw the child with Mary his mother, and they fell down and worshiped him. Then, opening their treasures, they offered him gifts, gold and frankincense and myrrh.

For more than two thousand years, people have tried to attach some astronomical meaning to the star.  From books and planetarium shows, I have gathered several; possible interpretations:

1. The star was Halley’s comet.  Unlikely, because Halley’s comet returned in October of the year 11 BCE.
2. An exploding star; a nova or a supernova.  Although we have no evidence of such an event in those years, there could have been one. 
3. A planetary conjunction. The Moon did pass close to Venus in the eastern sky (the location in the east appears twice in the biblical account).  My personal favorite is a conjunction between Jupiter and Venus, on June 17, 2 BCE.  However, 4this conjunction happened after the death of King Herod in 4 BCE, and it would have led the Magi in the wrong direction.

However, there was a Great Conjunction in 6 BCE. (Great conjunctions involve only Jupiter and Saturn and take place roughly every twenty years.)  A subset of this series involved the Moon passing close to Jupiter on April 17,  6 BCE.  True to the biblical account, Jupiter was in the east over Israel at this time, and King Herod was still living.

One thing I like about the planetary conjunction theory is that astrologers in those ancient days4, more than the general population, paid attention  to these events.  One possible translation of “wise men” is “astrologers”, people versed in how the stars and planets influence humanity.  They would have paid attention to planetary conjunctions more than the general population.

4. It could have been a miracle.  In my own life, I consider every night out under the stars as a miracle, so why not?

Whatever the Christmas star was,  we got to see it again as a ”Great Conjunction” on Monday, December 21^st.  It is the closest that Jupiter and Saturn have been close to each other since 1623, that long-ago year that also saw the first publication of the First Folio of Shakespeare’s plays.  On that day in 1623, the conjunction took placed in daylight, so no one would have paid attention to it.  But the one in 2020 was visible in the early evening!  Therefore, millions of people were definitely paying attention to it, and it reminds us of the Star of Bethlehem.  Whatever it was, we shall never know.  But for those of us who were able to gaze in wonder at this fabulous event, it acted to increase the nightly miracle of the magnificent sky.

         Even in our postmodern age, the chance close alignment of the sdolar system’s two biggest planets is not a big scientific event.  However, it is a big astrological happening.  While no true scientist follows astrology these days, two thousand years ago the night sky was all about astrology.  And were it not for ancient astrology, we would not enjoy today’s comprehension of the night sky.  Even in 1623, the last time Jupiter and Saturn were this close, most people were more interested in astrology.   I quote from Shakespeare, who was did not follow judicial in astrology.  The two opening lines of Sonnet 14 state clearly that

Not from the stars do I my judgment pluck,

And yet methinks I have astronomy…

I believe that Shakespeare used astrology a lot in his plays because he knew his audience followed it.  And now at the close of 2020, we have that rare opportunity to reflect on an astrological event, the joining together of two planets, a simple event that helps us to go outside, look towards the southwest, and revel in the beauty of  the night sky.

Photo Credit: Dr. Tim Hunter

First Light

By David H. Levy

For those of us who are not astronomers, the phrase first light means dawn.   If we are up early to go fishing, hunting, or to search for a missing person, we awake at first light.  For skywatchers, first light has an entirely different meaning.    Instead, it celebrates the first time starlight enters a new telescope or the inside walls of a new observatory.  On Sunday evening, December 15,  David Rossetter, one of the United States’s most famous amateur astronomers, celebrated first light for his new observatory, completed  after he relocated to the Tucson area.  Wendee and I were there, along with some neighbors, friends, and the new executive director of the International Dark Sky Association.

         The object David selected as the first thing to be observed from his brand-new observatory was Messier 15, one of the grandest globular star clusters in the entire sky.  It is different from the object I traditionally use for my new telescopes, the planet Jupiter.  Last fall, for example, I pointed Eureka, a brand new telescope, at Jupiter for its first light ceremony.

        Jupiter shines at us from about 50 light minutes away, meaning that light reflected from the Sun leaves it and takes about 50 minutes to reach us. The globular cluster Messier 15, is much much farther away. It shines at us from well beyond the stars of its home constellation of Pegasus, from a distance of at least 33,000 light years, and at magnitude 6.2, it is barely visible to the unaided eye on a very dark night. 

         I was very glad to see M15 using David’s giant 25-inch diameter reflector from his new observatory, for I recall seeing it frequently at our Adirondack Astronomy Retreat. At the first Star Night of the Montreal Centre of the Royal Astronomical Society of Canada, my first one since becoming a member, I was assigned Messier 15, the globular star cluster that was discovered by Jean-Dominique Miraldi in 1746, and added by the comet hunter Charles Messier to his catalogue in 1764.  I recently wrote about that experience in my autobiography:

“At Star Night that September I was assigned to point my telescope at M15, the beautiful globular cluster in Pegasus.  I recall doing my homework about that cluster. I learned that its distance was listed at about 33,000 light years.  We now know that M15 is also one of the oldest globular star clusters in the Milky Way, dating from at least 12 billion years ago.  We also suspect now that the central portion of M15 underwent a collapse of its core deep in the past, and that its central core consists of a huge number of stars orbiting a massive black hole.  Most of this information is more recent.  Back then the pertinent facts were that the cluster had a membership of upwards of a hundred thousand stars.”  (A Nightwatchman’s Journey, p. 68.)

Years later, I wrote: “On a beautiful clear night at one of our Adirondack Astronomy Retreats, I peered through Fritz, David Rossetter’s 25-inch Obsession Dobsonian reflector.  The telescope was pointing at Messier 15 in the Pegasus constellation, but what I had was not just a view.  It was an extended leisurely stroll among the stars of this cluster. I made some left turns, walked up hills, crossed bridges and explored valleys all decked with uncountable stars.”  (A Nightwatchman’s Journey, p. 289.)

         I thoroughly enjoyed another look at the beautiful and mysterious Messier 15 from David’s new observatory on that night.  I especially enjoy showing younger people this fabulous cluster of so many stars.  As each new generation is introduced to it, may Messier 15’s myriad stars shine for a distant and newer generation, or from another observatory as it undergoes its first light.

Image Credit: Phil Orbanes 2016

On Friday night, December 13, for our 16th annual Holiday Party, we are fortunate to once again have with us the celebrated Kelly Beatty, Senior Editor of Sky & Telescope Magazine (see more of Kelley's bio below). This year Kelly's presentation asks the perennial question "Are We Alone?

Our galaxy, Kelly writes, "likely contains more planets than stars — so what are the odds of finding distant Earth-like worlds that teem with life? After surveying the amazing diversity of life on Earth — and the theories of how it started here — we'll sample the kinds of worlds around other stars that astronomers have discovered and explore whether any of them might be suitable for life. And we'll catch up on efforts to contact alien civilizations directly, via radio transmissions and other means."

This will be a very entertaining and richly informative night, so come early and grab a good seat and some great food and conversation before all the festivities begin. See you there!

_____________

A little bit of Kelly's bio: 

Kelly has been honored twice by the Division for Planetary Sciences (DPS) of the American Astronomical Society. In 2005 he received the Harold Masursky Award for meritorious service, and in 2009 he was honored with the inaugural Jonathan Eberhart Journalism Award. He is also a recipient of the prestigious Astronomical League Award (in 2006) for his contributions to the science of astronomy and the American Geophysical Union's Cowen Award for Sustained Achievement in Science Journalism (2009).

Kelly hails from Madera, California. He holds a Bachelors degree in geology from the California Institute of Technology and a Master's degree in science journalism from Boston University. During the 1980s he was among the first Western journalists to gain firsthand access to the Soviet space program. Asteroid 2925 Beatty was named on the occasion of his marriage in 1983, and in 1986 he was chosen one of the 100 semifinalists for NASA's Journalist in Space program.

Skyward

October 2019: California and the Universe

Since early in the last century, astronomers dreamed of the clear sky over California as a place to unlock our imaginations and study the universe.    In 1917, the 100-inch Hooker telescope was opened to the poetry of Alfred Noyes, who wrote:

         We creep to power by inches. …Even to-     night

         Our own old sixty has its work to do;

         And now our hundred-inch: I hardly dare

         To think what this new muzzle of ours may find.

And just think what the niog telescope did find;  among many other things, it revealed that our Universe was double the size we thought it was.  Despite the fact that I have visited Mount Wilson many times, my most recent visit in September gave me an insight I hadn’t experienced before. I was a guest of Scott Roberts, whose Explore Scientific telescope company had organized an observing party there. The place literally oozes history through every stone, piece of wood, and gear revealing the progress of our understanding of the Universe as it increased during the 112 years since the observatory’s founding in 1907.  

During my visit there I felt as though I was standing next to some of these great astronomers, now long gone.  I was standing next to George Ellery Hale as he struggled to build the Snow solar telescope, the mighty 60-inch, and the 100-inch Hooker telescope.  I was standing next to Fritz Zwicky as he used the 100-inch on so many nights.  Zwicky had quite the reputation as a curmudgeon.  He might have included me among the many colleagues he called “spherical bastards” – meaning a bastard no matter which angle or prism you choose to look through.

I was standing next to Walter Baade.  There is a story that, at the outbreak of the second world war, he was declared an enemy alien and ordered to stay near his Pasadena home.  Since he, or someone, allowed the vicinity of Pasadena to include Mount Wilson, Baade essentually enjoyed three years of uninterrupted observing time on the 100-inch.  With Los Angeles under occasional blackout conditions that darkened the Mount Wilson sky still further, Baade made his crucial observations of individual variable stars in the Andromeda Galaxy that he, and Bart Bok, later used to determine the size and shape of our own Milky Way Galaxy.

George Ellery Hale was unsatisfied with the size and abilities of the big 100-inch telescope, and he longed for a much larger one.  He hired Russell Porter, the amateur astronomer who had founded the Stellafane telescope makers meeting in 1925, to work on a 300-inch telescope. When that was deemed impractical, a 200-inch telescope was built instead.   Porter’s drawings of the 200-inch were stupendous.  Realizing that the 100 was unable to reach the north celestial pole due to its English double yoke mount design, he envisaged a beasutiful and elegant horseshoe design so that the 200-inch could point right at the pole if needed.    Even the lowly 18-inch Schmidt camera telescope, the first telescope at Paliomar, made history as the instrument Zwicky uased to discover 100 supernovae in distant galaxies, and, near the end of its useful life, it was the telescope used in the discovery of Comet Shoemaker-Levy 9.

I close with a variation of a quotation by Sir Kenneth Clark.  What defines the great observatories that look to the stars and revolutionize our understanding of them? I don’t know.  But I know them when I see them.  And the observatories at Mounts Wilson and Palomar are them.

Images: Figure 1:  The venerable hundred inch telescope points toward the zenith inside its enormous dome at Mount Wilson. Figure 2:  This Seth Nicholson dome once housed the 12-inch Schmidt camera that now resides at Jarnac Observatory.  Both photographs by Doveed.

This Friday at 8:00 pm Barry Yomtov will be returning us to our regular monthly GAAC meetings with a presentation on "NASA -- the Glory Years," following NASA through the 1960's and into the 1970's. Those were exciting times, from the Mercury program through Gemini and a foreshortened Apollo program with its series of human moon landings.

Barry will also spend some time examining all the other efforts, large and small, that were needed to get the program up and running, from stitching spacesuits to actually making and delivering the massive Saturn 5 rocket.

This will be a colorful, fun and informative evening, one you won't want to miss. As always, we'll be at the Lanesville Community Center, 8 Vulcan St, 8:00-9:30 Friday evening, September 13. And as always, there'll be no dues or fees, lots of great company, great conversation, and lots of good things to eat and drink. See you there!

Skyward, September 2019

The AAR lives on!

About a year ago in this column I wrote about the final Adirondack Astronomy Retreat (AAR) that Wendee and I held in the Adirondack Mountains near Lewis, New York.  We had a special program with lectures, a banquet featuring, among other VIPs, my brother Gerry and his partner Duane, and President John Ettling of SUNY Plattsburgh.  We even presented to Dr. Ettling the first Starlight Night Prize to celebrate the University’s commitment to keep this wonderful place as dark as possible.   We concluded the week by burying a time capsule. 

Much as we tried, the enthusiasm for the event was too strong just to end it.  Now, under the direction of Patrice Scattolin from Montreal and his family, AAR is continuing.   With his high intelligence and brilliant sense of humor, Patrice ran the event with an efficiency and alacrity rarely seen.  Laurie Williams, with the assistance of daughters Clara and Sophie and son Marc, kept the indoor portion running smoothly.  And this year the weather helped “big-time.”  We had four beautiful nights, and good portions of two others.  Using the camp’s Meade 14-inch Schmidt-Cassegrain called Aart, a 26-inch reflector dubbed Enterprise, and Carl Jorgensen’s 8-inch reflector named Pegasus, I did almost 25 hours of visual comet hunting.  This total is possibly a record for this site.    When the sky is at its best here, I can glimpse Messier 33 with the naked eye and I did that almost every night.  The International Space Station made a nice pass, and we saw several bright meteors heralding the onset of the Perseid meteor shower.

The purpose of this particular retreat was and still is to recharge our astronomical batteries, and to remind us why we became amateur astronomers in the first place.    While last year we had plenty of down time to enjoy movies and singalongs, this year the night sky occupied pretty much all our time.   It was truly spectacular.   

While the site may be superb now, we chose it for our star party because of the memories that flood back every time I revisit it.  It provided my first serious dark sky experience decades ago, during the summers of 1964, 1965, and 1966.  I loved it so much back then that I asked Dad if I could attend SUNY Plattsburgh the rest of the year.  In one of the few mistakes Dad ever made, he resisted, preferring that I attend Montreal’s McGill University instead.  I flunked out of McGill twice.  But I have never forgotten the pristine beauty of SUNY Plattsburgh’s Twin Valleys campsite, with its unparalled views of the “forever wild” Adirondack mountains.  May this priceless spot continue to remind future generations of how beautiful the mountains are, and how beautiful the night sky remains far above their lofty peaks.   

This month we're fortunate to have Catherine Zucker of the Harvard-Smithsonian Center for Astrophysics as our guest speaker. Catherine will show us how we have begun to derive accurate distance measurements to large, star-forming molecular clouds in the Milky Way galaxy, and what that means for astronomy.

Why go to all this trouble? Obtaining accurate distance measurements to molecular clouds is important for understanding the star and planet formation process. The advent of large photometric surveys and the Gaia mission offer an unprecedented opportunity to derive the distances and properties of hundreds of millions of stars, as well as the molecular clouds between them. 

Without resorting to scary math, Catherine will explain how we have combined these data with statistical methods to create a new 3D map of molecular clouds in the solar neighborhood (the nearest 10,000 lightyears). As it turns out, these phenomena are surprisingly interrelated -- using interactive visualization software, we can find new connections between long-studied molecular clouds that reveal a link between individual star-forming regions and the larger Galactic environment.

Our speaker for the Friday, June 14 GAAC meeting will be none other than Steve O'Meara, the amateur astronomer who, very unexpectedly, observed "spokes" in Saturn's ring system in 1976. Steve reported observing these phenomena with the 9 inch refractor at Harvard (an interesting account of the reception of O'Meara's observations is available here, in the Journal of Astronomical History and Heritage). His observations were discounted by professionals and others who pointed out that no such thing could exist due to differential rotation of the rings.

In 1980 Voyager 1 visited Saturn, reported spokes in the rings, and got credit for the discovery, perhaps, some speculate, because of an inherent distrust of visual observation as opposed to photographic astronomy. In his talk, Steve will speak about his observations of Saturn and the events that followed. This is sure to be a fascinating and colorful account, and, incidentally, a welcome affirmation of the value of careful visual observational astronomy.

You'll definitely enjoy this evening at GAAC, hearing from a really accomplished and deservedly well known astronomer. We'll hope to see you there.

GAAC meets on the second Friday of every month except August, at 8:00pm at the Lanesville Community Center, 8 Vulcan St in Lanesville. There is no cost, and all are welcome.