Category Archives: lectures

LIGO and the era of multimessenger astronomy

Multimessenger astronomy is a fairly new buzz word in the science. Dr. Joey Key, an assistant professor of physics at the University of Washington Bothell and a member of the LIGO Scientific Collaboration, talked about the concept at last month’s meeting of the Seattle Astronomical Society.

Joey Key

Dr. Joey Key of the UW Bothell gave a talk about LIGO and the era of multimessenger astronomy at the Dec. 21 meeting of the Seattle Astronomical Society. Key made the same presentation to the Everett Astronomical Society Jan. 7. Photo: Greg Scheiderer.

As you probably know LIGO—the Laser Interferometer Gravitational-wave Observatory—made the first detection of gravitational waves, as predicted by Einstein’s theory of general relativity, back in December 2015 and announced the findings last February. So now what?

“The next big goal for LIGO is to have a gravitational wave detection where we also get an electromagnetic signal from the same source,” Key explained. She noted that various wavelengths of light, from gamma ray to radio, require different types of tools to detect and reveal different things about objects observed. Key said gravitational-wave astronomers refer to such science as “electromagnetic astronomy.” The big hope, then, is to learn even more if there can be an electromagnetic observation as well as a gravitational wave observation of the same event.

“That’s what we would call a multimessgenger source,” Key said.

A difficult search

Einstein never thought gravitational waves could be detected because he figured they would be too small. It took a century of technological advances to prove him right—again. Finding a multimessenger source may be an even more elusive needle in the cosmic haystack.

Key explained that, right now, it’s hard for LIGO to detect with precision from whence a source signal originates. When they detect a source they send an alert to about 60 electromagnetic astronomy partners and give them a general direction in which to look. In addition to the challenge of pinpointing the source, they also don’t really know what to look for. Key said their models aren’t very good, not yet anyway. Light from a source may have already passed, but there could be x-rays, gamma rays, afterglow, or shock waves under certain conditions.

Fortunately, LIGO is getting better. The addition of more Earth-based observatories will help better locate sources and discover collisions of neutron stars or stellar-mass black holes. Project LISA, scheduled to launch in 2029, will look for supermassive black hole collisions and “extreme mass ratio in-spirals” which occur when a little star or black hole falls into a big black hole. Pulsar timing arrays could detect when supermassive black holes collide in galaxy mergers. There’s even study of the cosmic microwave background to try to detect gravitational waves from early universe.

“Just like electromagnetic astronomy, different sources are detected by these different kinds of experiments,” Key said. “We need all these different kinds of gravitational-wave experiments to be able to study the gravitational-wave sky.”

The LIGO Scientific Collaboration includes more than a thousand scientists from 15 countries and 90 institutions. Four of the institutions are in Washington: The University of Washington, UW Bothell, Whitman College, and Bellevue College.

Unknown discoveries ahead

Key said it is an interesting time to be involved in the field as LIGO is just into its second observing run.

“We’re really going to be able to map out and explore the population of black holes in our universe,” Key said.

“We don’t know what we’ll discover, and that is always the story of a new astronomy,” she added. ”We do not know very much about black holes in general, and so this is a new way to study the universe and study what is out there. It will be very exciting!”

LIGO could discover new kinds of sources like cosmic strings, study supernovae, and maybe even lead to the detection of dark matter and dark energy.

“We are lucky we live in the era of gravitational-wave astronomy, and we hope soon that it will be the era of multimessenger astronomy,” Key concluded.


SU Search for Meaning Fest includes three talks with astronomy themes

If you’re looking for meaning you may be able to get some clues in February at Seattle University. The university’s annual Search for Meaning Festival is set for February 25, 2017, and will bring more than 50 authors and artists to campus to tackle topics surrounding the human quest for meaning and the characteristics of an ethical and well-lived life. Three of these talks may be of particular interest to astronomy enthusiasts.

ShetterlyMargot Lee Shetterly, author of Hidden Figures: The American Dream and the Untold Story of the Black Women Mathematicians Who Helped Win the Space Race (William Morrow, 2016) will give a keynote talk at the festival about race, gender, science, the history of technology, and much else. She will show us the surprising ways that women and people of color have contributed to American innovation while pursuing the American Dream. Hidden Figures has been made into a feature film that opens in theaters in January.

Marie BenedictMarie Benedict, author of The Other Einstein (Sourcebooks Landmark, 2016) will talk about her novel and explore the life of Mileva Maric, who was Albert Einstein’s first wife and a physicist herself, and about the manner in which personal tragedy inspired Mileva’s possible role in the creation of Einstein’s “miracle year” theories. She’ll also discuss how Mileva’s story is, in many ways, the story of many intelligent, educated women whose own aspirations and contributions were marginalized, or even hidden, in favor of those of their spouses.

CoyneRev. George V. Coyne, SJ, former director of the Vatican Observatory and currently the endowed McDevitt Chair in Physics at Le Moyne College in Syracuse, New York, is author of Wayfarers in the Cosmos: The Human Quest for Meaning (Crossroad, 2002). Father Coyne will talk about the history of the evolution of life in the cosmos—a history which may lead us to a deeper understanding of what many secular physicists say themselves about the cosmos: that a loving creator stands behind it.

The full schedule for the daylong event is available online. General admission tickets are $12.50 and are also available online.

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Dava Sobel and the ladies of the Harvard Observatory

If you don’t know the names Williamena Fleming, Antonia Maury, Henrietta Leavitt, Cecilia Payne, and Annie Jump Cannon, you’re not alone. Many people working in astronomy don’t recognize these women who have made enormous contributions to the field.

Dava Sobel

Dava Sobel talked about her new book “The Glass Universe” Dec. 15 at Town Hall Seattle. Photo: Greg Scheiderer.

“They’re making a splash now,” laughed Dava Sobel, author of the new book The Glass Universe: How the Ladies of the Harvard Observatory Took the Measure of the Stars (Viking, 2016). Sobel talked about the book Thursday night at Town Hall Seattle.

There is an impression that the women who worked at the observatory were trivialized or marginalized, Sobel said that really wasn’t the case.

“They really were well treated, they were given this tremendous responsibility, they made valuable discoveries, and they were well regarded—and some of them even world famous—in their own lifetimes,” Sobel said. She pointed out that Cannon, for example, held a number of honorary degrees, was a member and officer of the American Astronomical Society, and also was an honorary foreign member of the Royal Astronomical Society.

Interestingly enough, even Sobel, whose bailiwick is science history, hadn’t heard of Leavitt until her name came up during an interview for a magazine article she was writing 20 years ago. Her curiosity was piqued, and the seed for The Glass Universe was planted.

Cheap labor

Sobel noted that when Edward Pickering took over as director of the observatory in 1877 there were already a half a dozen women working there, many of them relatives of the resident astronomers. He liked working with the women. They did good work, and they were inexpensive.

“Women cost less,” Sobel said. “This is an old story about women earning less than men for doing the same work.”

But she added that it wasn’t just dollars and cents for Pickering.

“He was very open minded, broad minded, and felt that higher education for women was a good thing even at a time when this was questioned,” Sobel said. “There were people who really thought that college was bad for girls and could affect their ability to have children.”

Pickering recruited alumnae of women’s colleges who studied astronomy, asking them to make observations and contribute their data to the work of the observatory.

“That would be a way to prove to the world that women could make a contribution to science and that their education wasn’t wasted,” Sobel said.

Financial support from women

The observatory was a separate entity and didn’t receive any money from Harvard. Much of the work at the observatory was possible due to significant financial support from women.

Heiress Anna Palmer Draper and her husband, Dr. Henry Draper, had done some of the earliest work on photographing the spectra of stars. Henry Draper was a medical doctor, but he was, according to Sobel, a passionately engaged and inventive amateur astronomer. They built their own observatory and Henry created many of his own instruments for the work on spectra. Unfortunately, Henry got sick and died at the age of 45. Anna eventually donated much of their gear, and a lot of money, to the observatory to continue the work on stellar spectra.

Philanthropist Catherine Wolfe Bruce donated $50,000 to help the observatory set up a telescope in Peru for observing the skies of the southern hemisphere. Data from this instrument informed Leavitt’s work on variable stars.

Major achievements

The contributions by the computers were significant. A few examples noted by Sobel:

Leavitt studied variable stars and discovered that the brightest ones took longer to cycle through their changes, and that the length of the cycle correlated to the true brightness of the star. Knowing this, one can calculate how far away a variable star is based on how bright it appears from Earth.

Harvard women 1918

Some suggest this 1918 photo of Harvard College Observatory women in “paper doll” pose marginalizes them, but Sobel says they were regarded and treated well in their time. Photo: Harvard University Archives.

“This work was fundamental to distance measurements all over the sky,” Sobel said. The discovery, most often called the period-luminosity relation, is more often these days being referred to as “Leavitt’s Law.”

Cannon, a renowned observer, came up with the star classification system still in use today.

Fleming first came to the observatory as a maid, but later found astronomical success, too.

“She was the first woman to get a university title at Harvard,” Sobel said. “She was the curator of astronomical photographs.” Her analysis of some ten thousand stars were critical to the publication of the first Henry Draper Catalogue.

Maury, Draper’s niece, studied at Vassar, graduated with honors in astronomy and physics, and went to work at the observatory, where she came up with a system of identifying stars.

Payne was Harvard’s first Ph.D. in astronomy. It was no surprise that a woman earned the top degree first; all of the early graduate students in astronomy were women because the only money the observatory had for the graduate program came through fellowships established for women to study there. Payne studied spectra of stars and found that hydrogen was far more prevalent in stars than any other element. She wrote about her findings in her dissertation, but it was so counterintuitive that it was downplayed. Within a few years, however, her findings were confirmed.

Given the stature of the accomplishments, it seems astounding that these women are not more well known.

“A lot of history gets buried just because there are so many people, so many characters, so much time goes by,” Sobel noted, adding that the women didn’t feel marginalized at the time. “They really loved what they did and were credited for it, but over time I think it has been downplayed.”

They’re making a splash now

There’s been a lot more attention for the women astronomers in recent years. A decade ago George Johnson penned the biography Miss Leavitt’s Stars (W.W. Norton and Company, 2006). A couple of plays have been written about them, including Silent Sky by Laruen Gunderson, which was produced earlier this year in Seattle by Taproot Theatre. You can go back to read our coverage of the play. The 2014 reboot of the television series Cosmos with Neil deGrasse Tyson featured a segment about the computers.

“This got the attention of a lot of young women,” Sobel said. The Harvard women are also featured in the web series Insignificant.

“It’s great fun to see their story being remembered in so many ways. There are even Lego figures,” of Cannon, Leavitt, and Payne, Sobel said. “You know you’ve made it!”

Several other recent books have highlighted the work of women in space and astronomy. Sobel singled out The Rise of the Rocket Girls (Little, Brown and Company, 2016) by Nathalia Holt, a story about the women who made contributions to space science at the NASA Jet Propulsion Lab; and Hidden Figures (William Morrow, 2016) by Margot Lee Shetterly, a look at the African-American women who worked at Langley in the 1940s and ‘50s. Hidden Figures has been made into a feature film that is scheduled to open in theaters in January.

An important story for our times

Sobel said she enjoyed getting to know the personalities of the ladies of the Harvard College Observatory and feels that their story is an important one in the era of fake news and anti-science attitudes.

“All of us need to be telling true stories about science,” Sobel said. “I feel especially good about this one not only because it’s true, but because I hope it will be inspirational to young women to have models like these ladies and to show that women have always been interested in science.”

More books by Dava Sobel:

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Book review: Sun Moon Earth by Tyler Nordgren

Tyler Nordgren’s new book Sun Moon Earth: The History of Solar Eclipses from Omens of Doom to Einstein and Exoplanets (Basic Books, 2016) is a must read for anyone with even the slightest interest in the heavens, or in the total solar eclipse that will sweep across the United States on August 21, 2017. It’s far more than a where-to-go and how-to-see-it tale, although those pointers do show up at the end (don’t stare at the partially eclipsed Sun without proper, certified shielding, folks.) The fun part is the history lesson suggested by the subtitle.

Indeed, total solar eclipses have been happening for millennia, and Nordgren travels the world to examine what ancient cultures made of this unusual phenomenon. The complete blotting out of the Sun was seldom considered a good thing by people who didn’t understand what was really going on. It has only been in very recent times that the total solar eclipse has been embraced as a tourist attraction. Nordgren’s explanations of how scientific thinking developed and helped explain what was happening during eclipses are engaging and fascinating, as are his tales of the science that has only been possible during these rare events.

Nordgren has become an eclipse chaser himself, and I enjoyed his accounts of his travels to view eclipses, especially his trip to the relatively remote Faroe Islands, between Scotland, Iceland, and Norway, for the eclipse of March 20, 2015. The islands are not exactly the world’s leading tourism destination, and yet they were on that day because it was one of the few dry-land locations from which to see that particular eclipse. It was an interesting tale of the lengths to which people will go to get into the path of totality of a solar eclipse, and how the communities within that path prepare and react to the event.

Most people seem to agree that next year’s total solar eclipse will be seen by more people than any other in history. Often times the path of totality mostly passes over water, as it did for the Faroe Islands in 2015. The last time a total solar eclipse crossed the U.S. like this was in June of 1918. The 2017 eclipse will cross a huge land mass with a large population, many opportunities for tourists, and easy access to the path of totality all along the way.

Sun Moon Earth is a delightful read and would be a most welcome gift for anyone on your list with an interest in astronomy. We included it in our recent gift guide for astronomy buffs.

Tyler Nordgren

Tyler Nordgren

Author Nordgren is a renaissance man of sorts. He’s a professor of physics and astronomy at the University of Redlands. He’s also a photographer and an artist and has done a variety of beautiful travel posters for the eclipse as well as for other tourist spots around the solar system. They’re available on his website and also referenced in our gift guide. He’s done a great deal of work on night sky astronomy programs in National Parks. He’s the author of Stars Above, Earth Below: A Guide to Astronomy in the National Parks (Praxis, 2010) and spoke about the topic at the 2014 annual banquet of the Seattle Astronomical Society. He’ll be in town again to talk about Sun Moon Earth January 14 at Town Hall Seattle. Tickets are $5 and are available online.

Purchases made through links on Seattle Astronomy or through our store support our efforts to bring you interesting astronomy stories. We thank you!


Dava Sobel talk highlights week’s calendar

A talk by author Dava Sobel is the highlight of this week’s astronomy calendar. Sobel, whose new book is The Glass Universe: How the Ladies of the Harvard Observatory Took the Measure of the Stars (Viking, 2016) will speak at 7:30 p.m. Thursday, December 15 at Town Hall Seattle.

The book is the story of the contributions of women at the observatory who made major advancements in the science, often without getting proper credit or recognition. From Williamina Fleming, originally hired as a maid, who identified ten novae and more than three hundred variable stars to Dr. Cecilia Helena Payne-Gaposchkin, appointed as the first woman professor of astronomy at Harvard in 1956, this group of remarkable women disproved the notion that “the gentler sex” had little to contribute to human knowledge.

Tickets to Sobel’s talk are $5 and are available online.

Astronomy on Tap Seattle

December’s edition of Astronomoy on Tap Seattle will consist of three shows at the University of Washington Planetarium on Wednesday, December 14. The program will be a guided tour of the universe. Unfortunately, all of the seats for the three shows were snapped up quickly, but you might watch the AoT Facebook event page to see if any openings occur.

Public night in Pierce County

The Tacoma Astronomical Society plans one of its public nights for 7:30 p.m. Saturday, December 17 at the Fort Steilacoom campus of Pierce College. The indoor program will be a viewing of a movie about the Christmas star. If the weather is clear they’ll break out the telescopes for some observing, too.

Futures file

You can scout out future astronomy events on our calendar. The page also features a full schedule of planetarium and stage science shows at Pacific Science Center. Recently added events include:

Up in the sky

The Geminid meteor shower peaks this week, but will have to compete with the full Moon. The Sky This Week from Astronomy magazine and This Week’s Sky at a Glance from Sky & Telescope offer more observing highlights for the week.


David Grinspoon will make three northwest appearances in January

Folks in the northwest have three chances next month to hear a talk by astrobiologist, award-winning science communicator, and prize-winning author David Grinspoon. Grinspoon, author of Earth in Human Hands: Shaping our Planet’s Future (Grand Central Publishing, 2016) will speak at 7 p.m. Tuesday, January 10, 2017 at the University Book Store in Seattle. The following evening, Wednesday, January 11, he will appear at the Pacific Science Center at 7 p.m. as part of the center’s Science in the City lecture series. The following Monday, January 16, Grinspoon will speak at 7:30 p.m. at the monthly meeting of the Rose City Astronomers at the Oregon Museum of Science and Industry in Portland.

David Grinspoon

David Grinspoon

Grinspoon will assess climate change by comparing Earth’s story to those of other planets. Without minimizing the challenges of the next century, Grinspoon suggests that our present moment is not only one of peril, but also great potential, especially when viewed from a 10,000-year perspective. He’ll discuss the human impact on Earth and what we can do to shape our future. Possible implications for the search for extraterrestrial intelligence will be considered, as well as the choices our civilization faces in seeking to foster a wisely managed Earth.

Grinspoon is a senior scientist at the Planetary Science Institute and adjunct professor of astrophysical and planetary science at the University of Colorado. His research focuses on climate evolution on Earth-like planets and potential conditions for life elsewhere in the universe. He is involved with several interplanetary spacecraft missions for NASA, the European Space Agency and the Japanese Space Agency. He’s a contributing editor for Sky & Telescope magazine, and his work also has appeared in Astronomy and a variety of other publications. He often appears as a commentator on television, radio, and podcasts.

The lecture at Pacific Science Center is free for members, $5 for the general public; tickets will be on sale soon. The Rose City Astronomers and University Book Store events are free and open to the public.

Books by David Grinspoon:

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Beatty tapped as keynoter for SAS annual banquet

Kelly Beatty, senior editor for Sky & Telescope magazine and a board member of the International Dark-Sky Association, will be the keynote speaker at the Seattle Astronomical Society‘s annual banquet. The event is scheduled for 5 p.m. Saturday, January 28, 2017 at the Swedish Club on Dexter Avenue North in Seattle.

unnamed-2Beatty, who specializes in planetary science and space exploration, will give a talk titled, “Pluto’s Amazing Story.” He’ll cover the history of the former ninth planet from predictions of its existence and its discovery by Clyde Tombaugh to its “demotion” to dwarf-planet status and the amazing new data from the New Horizons mission.

Reservations for the event are available online now for members of the Seattle Astronomical Society, and will be made available to nonmembers beginning January 11. The member price is $45, and the nonmember price will be $60. There are two good reasons to join SAS right there: save a seat at the banquet now, and save $15. Annual dues are just $35, so you’d be almost halfway to paying it off!

(Disclaimer: While I’m a member of the Seattle Astronomical Society and often cover its events and activities, Seattle Astronomy is not formally affiliated with the society.)