The Gloucester Area Astronomy Club

David H. Levy

Daffy Duck

Agreed, this seems like an awfully daffy title for an astronomy article. But there is method to the madness, and there is a story.  During the late summer of 2019 there was a star party in southeast Arizona that featured a dark sky and five perfect back-to-back nights  As I spent hour after hour hunting for comets, I came across the sprawling North America Nebula in the northern sky constellation of Cygnus the swan. But this time something different appeared. It was a strange structure, the outline of a dark nebula bordered by a slightly brighter cloud.  The whole feature was rather subtle, so that sometimes it was there, and then it faded so that sometimes it wasn’t. I spent some time trying to determine a name for it. It looked like the head of a duck.  I couldn’t call it the wild duck nebula, as there is a cluster with that name.  And Donald Duck is a bit confusing. So how about calling it the Daffy Duck nebula?  

Thus, the structure is named after Daffy Duck. It is No. 403 in my catalog of interesting things found during my more than 56 years of comet hunting. I believe it is a small dark construction at the northern tip of the North America Nebula, about where Hudson Bay is not accurately located.  It could have been where the Gulf of Mexico is, but that area is virtually impossible to spot visually, even under a dark sky.  Like the Horsehead Nebula in Orion, it is very difficult to spot and it is best viewed only in a photograph.  The accompanying picture shows it at its top, a little to the left of center.  The accompanying photograph was taken using the Hubble Space Telescope.

There are more than four hundred other celestial objects that have come my way over the years.  Beginning with NGC 1931 which I spotted in January 1966, many of these are already well-known deep sky objects in the night.  But a few are interesting groupings of stars, called asterisms, that no one has pointed out before.  One of my favorites is a structure of faint stars I call “Wendee’s Ring.”

These always welcome objects in the sky are fun to observe and they enhance my enjoyment of my hours under the stars.  When I can see Daffy Duck, it reminds me of the happy hours I spent as a child at Beaver Lake, an artificial pond near the top of Mt. Royal in Montreal, that hosts dozens of mallard ducks. On clear, moonless nights now, I offer a cosmic hello to Daffy Duck and the many objects in the night sky I have come to treasure as good friends.

David H. Levy

Galaxies, just for the sake of argument

A few weeks ago, I received a message from Cameron Gillis, an amateur astronomer who wrote that he liked galaxies.  Just for fun, I decided to take the opposite approach, a philosophical reversal.  If he likes galaxies, then I hate them.  As we prepared for our meeting I began to explain the various reasons why I hate them.  When, for example, I am observing with a telescope and the Andromeda galaxy enters my field of view, I quickly leave the telescope and ride my bicycle to the end of our driveway and back.    The more I stretch the story the greater the laughter becomes.  I especially get annoyed by the dark Hydrogen-II regions that stretch across  its hideous girth.  The cluster of galaxies in the Virgo cluster, particularly Messiers 84 and 86, are so bland that I sometimes have to leave the telescope altogether!    

The worst galaxy is our own. When I look up at the evening sky, the Milky Way obstructs my view as it straddles the night from Cassiopeia all the way down to Sagittarius. The stars are so thick that I can hardly see black sky between them.  Except of course, when I come across Baade’s window.  This area of sky  rattles me because there,  some darkness appears.  Discovered by Walter Baade, this window allows us to see almost to the center of our galaxy.  It is an awful sight. The majesty of the night is nowhere more apparent than when I am viewing the center of our galaxy, in Scorpius and in Sagittarius, through my telescope.  It is wondrous. So wondrous that I still hate it. Because it wastes my time when I am mesmerized by it, the emotion of viewing the galaxy from my backyard is so strong that it strengthens my heart and pierces my soul.

The worst part of seeing our own galaxy on a clear autumn night is that the dark lanes of hydrogen dust straddle its length. Dark areas are called giant molecular clouds. They are not lit by nearby stars; they just are there.  In the far distant future, they will generate new systems of stars and planets like our Earth.  They are called giant molecular clouds or Hydrogen  (H II) regions.

In distant external galaxies, dark clouds like these can straddle their whole length. The Andromeda galaxy has several of these H II regions that one can observe through a small telescope if one looks carefully enough.

Deep in the southern sky, but still visible from most of North America, lies Caroline Herschel’s galaxy.  It is No. 253 in the NGC, the New General Catalogue.  Under a bright sky it is hardly anything, but from a dark site it resembles a long resting caterpillar. It has a most prominent dark hydrogen lane running across its length.

Along with  globular star clusters, those round conglomerations of hundreds of thousands of stars that orbit the outskirts of galaxies, including our own, galaxies are the oldest structures in  the Universe. The oldest ones started to build within half a million years of the Big Bang, when the Universe was in its infancy.

So much for hating galaxies. When I say that I hate them, I write merely for the sake of argument and humor.  Galaxies are almost like people, each one different, each one with its special characteristics. One way of looking at them is to compare their gigantic sizes with our puny selves. But there is another way.  Small as we may be, each of us is unique. Galaxies are huge, but aside from their differing shapes, they are still much alike. But in all this Universe, among all these galaxies, there is just one, only one, of each of us.  Our ideas, our personalities, are precious.

Observing the universe relies to a great degree on our ability to model starlight, and thereby predict underlying stellar properties, such as mass and chemical composition.

At our 8:00 pm, Friday August 13 GAAC meeting, Center for Astrophysics Dr. Seth Gossage will continue the thread begun by our July speaker, Dr. Ioana Zelko, asking how we can know what we are looking at. What can the light we detect tell us about the object, so very far away, that produced it?

Light can reveal more about a star than just stellar mass and chemistry. Dr. Gossage will also, and in particular, review next generation stellar models built to explore the effects of stellar rotation. Stars spin, and this is also a fundamental stellar property (alongside mass and chemical composition), which helps determine the evolutionary course of a star, and its light output for the entirety of its lifetime.

Our August 13 meeting will be held again at our old home, the Lanesville Community Center at 8 Vulcan Street in Lanesville. We hope you can be there in person. For those who can not make it, the meeting will also be streamed on the GAAC Facebook page.

GAAC will return to in-person meetings at the Lanesville Community Center on July 9. There's great ventilation at the LCC, and we're confident that the timing is right. Come and spend a summer evening with all your old astronomy friends, make some new ones, and catch a terrific presentation. It will be great to see everyone again. There will be pie.

Our guest speaker on the 9th will be Ioana Alexandra Zelko, from the Harvard-Smithsonian Center for Astrophysics, on a question you may well have considered yourself: how is what we see affected by what we're looking through? Her talk is titled "Dust and the CMB Spectral Distortions Measurements."

Here's what it's about. Over the past 30 years, the cosmic microwave background (CMB) has profoundly influenced our understanding of the history of our universe, and ushered in an era of precision cosmology. The spectral distortions of the CMB can reveal a lot about exotic physics in the early universe, but we're still not sure how foreground dust is affecting our measurements, or the new physics that the CMB is generating.

We need to know what we're looking through. The proposed PIXIE mission, for Primordial Inflation Explorer, would detect and characterize the signature of primordial inflation, and would, of necessity, distinguish cosmological signals from nearer astrophysical foregrounds based on their different frequency spectra. Ioana will discuss her work on foreground dust and the CMB, and take us through current and future research on the topic.

David Levy's Skyward: Faint Fuzzies

The night before last, a comet named Palomar (actually known as C (for comet)/ 2020 T2 Palomar) was gliding near one of the most beautiful clusters of stars in the entire sky.   It was parading about at about magnitude 11, which means that for my oldish eyes, it would be too faint to see.  In fact, just a few weeks ago I spotted a second comet, named ATLAS.  That comet, at ninth magnitude, was so diffuse that I barely spotted it. So I was not going to try for this other comet.

However, this other comet was named Palomar after one of my favorite observatories!  The mighty 200-inch telescope was opened in 1948, just a couple of weeks before I was born, and the big telescope has been sighting stars for more than 70 years. In 1994, I was allowed to sit in the prime focus cage, that beautiful place where light from what the telescope is seeing comes to a perfect focus.  So sighting a comet with that hallowed name would be special.  

The comet was discovered by Dmitry A. Duev on images taken using Palomar’s Oschin Schmidt telescope last October.   As the comet was brightening slowly, I  learned that on Friday evening, May 14, the comet was planning to glide past Messier 3, one of the brightest globular star clusters in the whole sky.

That was just too much to resist.   Clusters of stars are scattered all over the sky, and our own galaxy has more than a hundred of them.  Globular clusters consist of hundreds of thousands of stars.   Messier 3 was discovered by Charles Messier, the famous Parisian discoverer of comets; it consists of some half a million stars and is more than 32,000 light years away.  At about 11.4 billion years old, it is also one of the oldest things in the universe.

With the onset of darkness that Friday evening, I set up my telescope in my backyard observatory and pointed it toward Messier 3.  The exquisite star cluster made its appearance. Then I nudged the telescope just a little bit to a nearby field of stars.   Suddenly I spotted  a faint fuzzy spot precisely where Comet Palomar was supposed to be. As I looked around, a meteor scratched the sky to the north.  It was a bright and unusual member of the May Ophiuchid meteor shower, a bonus on this unforgettable night.

Comet Palomar is the 219^th comet I have seen during my lifetime.    Most of these comets have also been faint, barely visible spots of haze.  But some have been wondrous.  My first comet, Ikeya-Seki, was the great comet of 1965.  Whether a comet is a faint fuzzy of a magnificent comet with a long tail, they are always welcome visitors to the Earth’s region of the solar system, each one signing, as comet finder Leslie Peltier loved to write, “its sweeping flourish in the guest book of the Sun.”

Photo Credit: David H. Levy. This is the dome for the 18-inch telescope, which Gene and Carolkyn Shoemaker and I used to  discover tall of the Shoemaker-Levy comets, including the one that collided with Jupiter in 1994. 

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!

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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.