July 12 GAAC Meeting Program Note: Molecular Clouds and Star Formation

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.

GAAC June 14 Meeting Program Note

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.

David Levy's Skyward -- May 2019

Skyward -- Trinity

May 2019

As the world prepared for war in 1939, a group of physicists was studying how to reproduce the behavior of a star on Earth:  to split an atom, either quietly to provide a virtually unlimited source of power, or explosively to create a weapon of mass destruction.  Worried that the Gemans might develop an atomic bomb first, astrophysicist  Leo Szilard wrote a letter to President Roosevelt suggesting that the Americans should develop the bomb first.  Thinking that the letter would have more impact if it were signed by the foremost scientist of that time, Szilard made two visits to Albert Einstein’s summer home in Cutchogue, on Long Island, New York.  They persuaded him to sign the letter.

Einstein’s letter had an immediate and powerful impact on Roosevelt.  He immediately set in place the initial research that led to the start of the Manhattan project in June of 1942.  Within three years, the first plutonium nuclear device was test detonated near Socorro, New Mexico in the Jornada del Muerto (ironically translated to Dead Man’s Journey) desert.  J. Robert Oppenheimer named the actual test site Trinity, after the first lines in John Donne’s Holy Sonnet 14:  

Batter my heart, three-person'd God, for you 

As yet but knock, breathe, shine, and seek to mend; 

That I may rise and stand, o'erthrow me, and bend 

Your force to break, blow, burn, and make me new.

 On July 16, 1945, at 5:29:45 am, the nuclear device detonated and the atomic age began.  Just one month later, two bombs were exploded over Hiroshima and Nagasaki, Japan,  and the Second World War came to a sudden end.

It is now 73 years later.  On April 6 our daughter Nannette, son-in-law Mark,  grandson Matthew,  friend David Rossetter, and Wendee and I visited Trinity Site.    It was a special and emotional experience for us.    We felt the shudder and silence of those who witnessed the blinding flash of light that turned dawn into noon across that lonely desert.  The power and force of the detontion reinforced the feeling of scientists there that this weapon was not a joke.    It was used in combat twice, and it is now a part of history.  We visited that day to expeience the effect on people who felt the shock wave from 160 miles away and who had to replace broken windows in Albuquerque, where our family lives today. We didn’t see much trinitite there, as the army did an excellent job removing the radioactive glass.  We did not get much exposure to radiation either; accoding to Army statistics, our one hour visit to Ground zero gave us at most one millrem of radiation exposure, compared to an average annual dose of 620 millrems from medical and natural sources.

As we left the site we passed a protest going on at the entrance.  After all these decades, what happened that rainy July day in 1945 still has a profound effect on the people who lived and live in the atomic age.  For a second that day, humanity witnessed the process of a star here on Earth.  And when I got home that night and looked up at the peaceful stars, I shuddered again. 

Picture 1:  Inscription on the obelisk at Ground zero.

Picture 2:  remains of a footing from the tower that supported the bomb and which was incinerated that day.

Picture 3:  The Schmidt-McDonald house, where the bomb was assembled.  All photographs were taken by David Levy.

GAAC Program Note -- May 10 Meeting

At our May 10 meeting, Amateur astronomer and perennial GAAC favorite Dwight Lanpher will speak about his visit last September to Birr Castle, County Offaly, Ireland to examine "the Great Telescope." Any review of the history of astronomy will likely discover this large telescope called the "Leviathan of Parsonsonstown." Built in Ireland in 1845 by the 3rd Earl of Rosse, it was the largest telescope in the world for 70 years. Each of two 72" speculum-metal mirrors were alternately mounted in a 54' long tube, suspended between two purpose built castle walls.

Dwight's dynamic presentation will show details of how the telescope was operated and the modifications that were made during a $1,200,000 renovation in 1995. Images will also include the last remaining of the two, 3-ton, speculum mirrors examined during the return trip at its current location at the Museum of Science in London.

When not visiting ancient telescopes, Mr. Lanpher travels throughout New England and eastern Canada attending astronomy meetings as liaison for clubs in Maine, New Hampshire and a few, including GAAC, in Massachusetts, and observing at their star parties when the opportunity avails. Professionally, Mr. Lanpher works as an Electrical Engineer.

This will be a fun, informative meeting, full of large telescopes, a large chocolate cake, and large but thoroughly graspable ideas. We hope to see you there!

David Levy's Skyward -- April 2019

Skyward, April 2019

During our monthly star nights at our neighborhood Corona Foothills Middle School, I sit down on a chair near the telescope to assist with the observing. The students attending are well behaved no matter their level of interest.  Some of the kids are there just for the evening’s assignment.  But occasionally one student or two will sit down next to me and ask me a few questions. 

They don’t have to do this.  They may ask how I got started in astronomy, in a time without computers, or even what my favorite planet or comet is.  I love these conversations.  They signify to me that the girl or boy is developing an interest in the sky, and an inquiring mind is at work that is so rare and precious these days.  That interest and curiosity may go nowhere; it may persist for a few months, or it may go everywhere.

Why are relatively few young people getting into astronomy? Is it because almost no astronomy is taught in schools these days?  Too much TV?  The internet?  Or are astronomy clubs failing to reach the young people of tomorrow? I would say all of these.  Or more to the point, none of these.  When I became interested in the night sky at the age of 12, there were even fewer astronomy lectures in school than now.  I went into astronomy partly because it offered me a reprieve from the lack of friends I had as a child—I was very shy.  And I embraced it because of an increasing innate love of the night sky.  I knew nothing, but that’s all that was needed.

Now, Wendee and I are offering youngsters a chance to inquire about the night sky.  Even if that interest is sparked among only a few, it doesn’t really matter.  Our attempt might have succeeded with one child.  Or five.  But it did succeed.  The way I see it, we cannot force a child to develop an interest in anything.  The spark that sets off a curiosity, even a lifelong curiosity, must come from the child.

I might have developed an acquaintance with astronomy partly because I was searching for an interest that did not involve having to make friends. But my passion for the sky came from the sky itself and its complement of worlds, suns, and galaxies. After many years, I have made lots of friends, most of whom also love astronomy, but in a way it doesn’t matter.    What began as something to avoid friendship has evolved into one of the friendliest and happiest things I’ve ever done, a lifelong friendship with the starry host that brightens our nights.

Picture Caption: "This picture shows me demonstrating Voyager, our Meade 14-inch diameter reflector telescope, to one of the students."

Skyward -- March 2019

David Levy

Skyward, March 2019

  If you have read this column more than once, you probably are not too surprised to understand that I love comets.  Comets are a part of me, a part of who I am. 

But I had to wait a while before I saw my first comet.  I was already 17 years old and had been interested in the sky for a number of years.  When I learned that the two young Japanese amateur astronomers Kaoru Ikeya and Tsutomu Seki had discovered a comet that could become the comet of the century, I was spellbound.  During the mild autumn of 1965, as I awaited this mighty comet, I decided to begin a comet search program of my own. 

At the end of October I finally saw this comet as it rose, tail first, in the sky to the east beyond the St. Lawrence River.  I observed it again a week later in early November.  I have never forgotten it, even as, in later years, I finally was able to correspond with the comet’s two discoverers.   Their comet did become the brightest comet of the 20th century, and my own program, after many more years of searching,  was successful.

To me, comets are as personal as almost anything in my life.  I have discovered or co-discovered 23 of them, but my favorite is Comet Hyakutake. (prounounced Yah-koo-tah-key.)  This comet provided everything a great comet should:  it was big, it was bright, and its tail stretched majestically across the sky.  I followed the tail one night from Polaris, the north star, all the way past Corvus in the far southern sky.  When I reported my observation, a professional astronomer wrote to me that it was simply impossible for the tail to be so long.  In order for that to happen, the tail would have had to stretch from Earth past Jupiter.  A few years later, scientists studying the data from the Ulysses space probe identified its detection of the tail at the orbit of Jupiter, and the astronomer confirmed what I saw.

There is one other aspect that I can write about Comet Hyakutake.  Between the time it passed so close to the Earth and the time it passed close to the Sun a couple of months later, Wendee and I were growing closer.  One evening as we were driving home to Arizona from Las Cruces, New Mexico, I pulled over, turned off the car, and we enjoyed the comet together as it was ner its perihelion, or its cloest point to the Sun.  It was the first time Wendee saw a comet.  She saw another one, Hale-Bopp, the next year on our wedding night. And on October 3, 2006, she saw a third comet, one I had discovered the previous morning.

Oh, how I wish that more young people could capture this love of the night sky.  Maybe soon another bright comet will pay us a visit, and a young teenage girl or boy will look up, watch it wander lazily across the sky, its tail pointing off in some direction, and maybe this comet might inspire that young person to learn about the night sky that is so much a part of us.

Picture Caption: Halley's comet, taken with the 61-inch telescope at Mount Bigelow, near Tucson, Arizona.  The image clearly shows a bright tailward jet of dust emanating from the nucleus.  Picture by Steve Larson and David Levy.

David Levy's Skyward

March 23

In 1963, while living as a patient at the Jewish National Home for Asthmatic Children in Denver,  I strolled outside on the evening of March 23 to observe the evening sky.  The sky was brilliant and clear that evening so long ago as I set up my small first telescope, Echo, and proceeded to sketch a portion of the Milky Way as it shone in  the sky over Denver.  It was a silly and immature project of no particular value whatsoever, but it was important to me, and it resulted in a small chart of the winter Milky Way.

Over many years, the particular date of March 23 has brought many treasured  memories to my personal life and my skywatching life.   Late in 1988 I began studying the behavior of TV Corvi, a certain variable star that had been discovered in 1931 by Clyde Tombaugh, the same person who discovered Pluto. On the evening of March 23, 1990, TV Corvi erupted againlike a nova, brightening from fainter than magnitude 19 to magnitude 12, an increase of almost 250 times in brightness in just a few hours.    Even though it has gone through outburts of energy many times since then,  one of those outbursts also took place on another March 23.

All these events paled in contrast to what happened next.  On March 23, 1993,  Gene and Carolyn Shoemaker and I, while observing from Palomar Observatory, took the two photographs of a region of sky that led to our discovery of Comet Shoemaker-Levy 9.  Sixteen months later, the 21-odd pieces of that tidally disrupted comet collided with Jupiter, the largest planet in our solar system, in what is now regarded as the mightiest collision ever witnessed by humanity.  This event captured the attention, and the imagination, of the world, and was directly responsible for inspiring many people to become interested in the breathtaking majesty and behavior of the universe.   

The fact that my youthful map of the Milky Way, a new variable star, and one of the most interesting comets in the history of science (according to scientists around the world),  all began on March 23, left a most lasting impression on me regarding that special date.   In the nonastonomical parts of my own life, on March 23, 1992, I typed a postcard to Wendee Wallach, a teacher in Las Cruces, New Mexico.  It was my not very romantic way of asking her out on a date.  At the time it was just a coincidence that the letter was written on that particular date.  But five years later, it was not a surpise, therefore, that Wendee and I were married on March 23, 1997. 

There is a special reason that March 23 recurs in this way.  The various astronomical happenings associated with this date comprise not just a single part of astronomy, like a planet, a comet or a star that suddenly changes in bightness, but almost the whole gamut of what can happen in the sky, from a comet that collides with a planet, to a unique variable star, and on to the vast expanse of our galaxy across the night, and how all these things relate to the happiest parts of my personal life.  The date reminds me once again of how exciting and unexpected the night sky can be.

Nov 9 GAAC Program Note

This month we're pleased to have as our speaker Sarah Blunt from the Harvard-Smithsonian Center for Astrophysics. Sarah's presentation is titled "Know thy Star, Know thy Exoplanet."

Sarah's talk is based on the simple fact that nearly every known exoplanet has been discovered indirectly; that is, in order to detect and characterize the planet, we make measurements of its host star.

Because of these relationships, many exoplanet measurements have been limited by our knowledge of their stars at the time the planets were detected. In this talk, Sarah will discuss exoplanet discoveries that have now been made possible by more precise stellar data, and will introduce ongoing stellar research that has the potential to improve our understanding of exoplanets.

There are more planets out there than stars --  hundreds of billions just in the Milky Way alone.

See you there, 8 Vulcan Street in Lanesville, 8:00 pm on the 9th -- lots of good things to eat, lots of fun stuff to know, and great conversations to be had!