Orange County Astronomers

Open Spiral Bar
2022-03-12 22:00 - 23:30, 2022-04-09 22:00 - 23:30, 2022-05-14 22:00 - 23:30, 2022-06-11 22:00 - 23:30, 2022-07-09 22:00 - 23:30, 2022-08-13 22:00 - 23:30, 2022-09-10 22:00 - 23:30, 2022-11-12 22:00 - 23:30 (America/Los_Angeles) and 7 more dates | Online
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Come and socialize with your fellow astronomy enthusiasts face-to-face virtually!
Bring your latest astrophotography, mini-presentation, questions or none and your own refreshments.

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Online General Meeting - April 2022
2022-04-08 19:30 - 21:30 | Online
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The End of the Beginning

We used to think the Big Bang meant the universe began from a singularity. Nearly 100 years later, we’re not so sure. The Big Bang teaches us that our expanding, cooling universe used to be younger, denser, and hotter in the past. However, extrapolating all the way back to a singularity leads to predictions that disagree with what we observe. Instead, cosmic inflation preceded and set up the Big Bang, changing our cosmic origin story forever.

Download PDF of the presentation

Ethan has lived his life fascinated with one simple fact: we have the capacity to figure out definitive, scientific answers to even the deepest questions we can conceive about our physical reality. We do that by asking the right questions about the Universe, and then putting the Universe itself to the test. From where everything comes from to the Universe’s ultimate fate and all that lies between, he’s committed to not just figuring it out, but to sharing the answers — what we know and how we know it — with anyone curious enough to listen.

https://www.startswithabang.com/

https://twitter.com/StartsWithABang
https://www.facebook.com/startswithabang

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Online General Meeting - May 2022
2022-05-13 19:30 - 21:30 | Online
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Oumuamua: The nearest exoplanet?

When ‘Oumuamua passed by Earth in October 2017, the only thing certain about it was that it was not from this Solar System. Because of its high velocity, it was the first confirmed interstellar object. The next year the object 2I/Borisov was the second confirmed interstellar object. But whereas Borisov behaved very much like a comet (albeit an unusual one), mysteries remain about what ‘Oumuamua actually is. Although it pushed away from the Sun by a rocket effect, like comets, it could not be made of water, or contain much carbon monoxide or dust, making it very unlike a comet. The acceleration it experienced was very large, and from the variations in sunlight it reflected, it was more elongated than any other solar system object: either a very skinny pancake or a very long cigar. Dozens of explanations have been proposed to explain these oddities, and speculation has run rampant, with some astronomers even suggesting it was alien technology. The truth is more mundane but no less exciting. In a pair of papers in 2021, Steve Desch and Alan Jackson demonstrated that ‘Oumuamua is consistent in every way with being a small fragment resembling the surface of Pluto. Our own solar system must have ejected trillions of fragments like ‘Oumuamua in its early days, and a population of fragments from the surfaces of Pluto-like exoplanets must be common throughout the Galaxy. ‘Oumuamua itself may have been ejected about 400 million years ago, from a Pluto-like exoplanet in a young system in the Perseus arm of the Galaxy. ‘Oumuamua is arguably the closest we’ve ever come to directly observing the surface of an exoplanet.

Steve Desch is a Professor of astrophysics in the School of Earth and Space Exploration at Arizona State University. He studies the formation and evolution of planets, the origins of the Solar System, exoplanets, and meteorites. He has written about ‘Oumuamua in the popular press and is thrilled to have contributed to our scientific understanding of this unique object.”

https://slate.com/technology/2019/01/oumuamua-alien-ship-anthropomorphize-space.html

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Online General Meeting – June 2022
2022-06-10 19:30 - 21:30 | Online
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Three Decades of

the Hubble Space Telescope

After decades of discussion and construction, the Hubble Space Telescope was finally launched on April 24, 1990. While HST was not the first space telescope, it represented a major expansion in capability that has helped upend humanity’s understanding of the universe. HST helped show that the expansion of the universe is accelerating, and has transformed our view of the universe with a remarkable set of Hubble Deep Field images, amongst other things. Along the way, the engineers, scientists and astronauts behind HST managed to overcome a debilitating optical problem and have kept HST making discoveries for more than three decades. Now HST is about to work in tandem with its successor, the James Webb Telescope.
Not Yet Imagined E-flyer

Christopher Gainor is a historian of technology specializing in space exploration and aeronautics. He has written four books on the history of space exploration and two on Cold War history. His most recent book is a history of Hubble Space Telescope operations published by NASA. Gainor is editor of Quest: The History of Spaceflight Quarterly. From 2018 to 2020, he was President of the Royal Astronomical Society of Canada, and he is a fellow of the British Interplanetary Society. Gainor holds a Ph.D. in the history of technology from the University of Alberta, and has worked as a history instructor at the University of Victoria and the Royal Military College of Canada.

https://chrisgainor.ca

https://www.facebook.com/Gainorbooks

https://twitter.com/chrisgainor
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Online General Meeting – July 2022
2022-07-08 19:30 - 21:30 | Online
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Rovers on Mars: 21st Century

Natural History

Expeditions to Another Planet

Perseverance and Ingenuity are the current culmination of a long list of missions to Mars. During the first 400 days of operation on the surface of Mars Perseverance has traveled over 12 kilometers and Ingenuity has flown 28+ times. In addition to observations focused on understanding the geologic history and context of four+ samples collected for eventual return to Earth at this time, Perseverance has made a variety of observations of the atmosphere and the moons of Mars. At the time of this presentation we will be well into the exploration of the enormous delta deposited by an ancient river onto the floor of Jezero Crater where Perseverance landed.

Larry S. Crumpler, Ph.D. is Research Curator in Volcanology and Space Sciences at the New Mexico Museum of Natural History and Science. He received his doctorate from the University of Arizona in Planetary Sciences and MS from the University of New Mexico in Geology. Prior to the Museum, he worked at Brown University.
He is a member of the Perseverance Rover Mission science team where he is responsible for geologic context mapping of the terrain traversed by the rover. Previously, he was a team member on Ingenuity helicopter development, Mars Exploration Rover (Spirit & Opportunity) where he served as “Long-term Planning Lead,” Mars Odyssey Gamma Ray Spectrometer, and Mars Reconnaissance Orbiter Camera (HiRISE).
He previously participated in NASA’s Viking and Pathfinder Mars, Magellan mission to Venus, Russian Mars 96 mission planning, Mars landing site selection and rover field tests. He has published numerous research papers, book chapters, and geologic maps; and a book about Mars that will be published by Harper-Collins in late 2021. He is a Fellow of the Geological Society of America.
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Online General Meeting – August 2022
2022-08-12 19:30 - 21:30 | Online
This is a free and open to the public online event.
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The Backstory of Contact Binary Stars

Contact binary star systems have the remarkable property that they orbit so closely they share a common atmosphere. They are the most common type of eclipsing binary star system. Despite extensive observations over more than a century, answers to the most fundamental questions have eluded scientists until now: How do they form? How do they survive tranquilly in contact so long? What becomes of them in the end? An outburst in 2008 showed directly that contact binary stars end their long lives by merging in an explosive event known as a red nova. This presentation will reveal the recently uncovered backstory that answers these questions, and it will conclude by considering how these answers might help identify which contact binary will be the next to explode.

Professor Larry Molnar earned a B.S. in astronomy from the University of Michigan along with an MA and a PhD in astronomy from Harvard University. (Hence, he has the three-degree background appropriate for one studying the Universe) He was a postdoc at the Smithsonian Astrophysical Observatory and taught at the University of Iowa. He has been a professor of Physics and Astronomy at Calvin University since 1998.
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Online General Meeting – September 2022
2022-09-09 19:30 - 21:30 | Online
This is a free and open to the public online event.
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Cosmic rays, antimatter, dark matter:

connecting the dots

In August 1912, Austrian physicist Victor Hess made a discovery that opened a new window to the most energetic phenomena happening in the universe: he had discovered cosmic rays. Cosmic rays are high-energy charged particles coming from space and striking the Earth from all directions. After a century of transformative discoveries and advancements, cosmic-ray physics is a lively and interdisciplinary field of research. In recent years, space-born experiments have delivered many new measurements of cosmic-ray protons, nuclei, electrons, and their antiparticles which generate renewed interest and prompted new open questions. This colloquium will address the main open questions in cosmic rays concerning their nature, their origin, and their connection with the dark matter puzzle. Emphasis will be given to the rare antimatter component, which is a promising discovery tool for new fundamental physics or exotic astrophysical phenomena.

Nicola Tomassetti is an astroparticle physicist and space scientist. He is an associate professor at the Department of Physics and Geology at the University of Perugia, Italy. His research interests include cosmic rays, dark matter, antimatter, heliospheric, and space physics phenomena. He is part of the Alpha Magnetic Spectrometer collaboration for the search for dark matter and antimatter in space. He teaches introductory physics, space physics, cosmology & astroparticles for undergraduate, master’s degree, and PhD students.
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Online General Meeting – October 2022
2022-10-14 19:30 - 21:30 | Online
This is a free and open to the public online event.
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The Dynamic Sky:

How We Find Discover and Understand

Stellar Explosions in the 21st Century

Humans have recorded the appearance of “new stars” since prehistory, but only in the last century have astronomers begun to understand their nature as stellar explosions. These “supernovae” provide clues about the lives and deaths of stars, the formation and evolution of galaxies, the production and distribution of chemical elements (including those required for life on Earth), and even the accelerating expansion of the Universe.

In the last two decades, the discovery rate of supernovae has ballooned from hundreds per year to tens of thousands per year, and in the coming decade, it will reach into the millions. This explosion can be traced back to the same technological advances behind the Internet age: high-speed telecommunications, digital imaging, increased computer processing power, and machine learning. This presentation will explore the history and future of supernova observations, with a focus on the technology behind them and the science they enable.

Dr. Griffin Hosseinzadeh is a postdoctoral researcher at Steward Observatory at the University of Arizona, where he studies various types of stellar explosions. He was previously a postdoctoral researcher at the Center for Astrophysics | Harvard & Smithsonian. He received his bachelor’s in physics from UC Berkeley in 2012 and his Ph.D. in astrophysics from UC Santa Barbara in 2018.

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Online General Meeting – November 2022
2022-11-11 19:30 - 21:30 | Online
This is a free and open to the public online event.
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X-raying the Winds of Giant Stars

We are made of stardust—or, at least in significant parts, of material produced in giant stars. These giant stars have strong winds that strip away the outer layers of stellar material. To understand giant stars, astronomers thus need to understand their winds. In this talk, Dr. Grinberg will explain why astrophysicists use space-based X-ray telescopes such as ESA’s XMM-Newton to study such winds and show how they are using black holes and neutron stars as backlights to make such stellar winds visible.

Photo:Friedhelm Albrecht/Universität Tübingen

Dr. Victoria Grinberg is an astrophysicist working in the Netherlands for the European Space Agency (ESA) where she helps ESA communicate with the scientific community. After her PhD in Germany, her research has taken her around the world – USA, the Netherlands and again Germany – before accepting her current position. Using space-based telescopes, Dr. Grinberg is studying the most extreme environments in our Universe: black holes, neutron stars, and the winds of the most massive giant stars. She also publishes on sustainability and climate crisis from an astrophysics perspective. In her free time, Dr. Grinberg creates cartoons about science and academia.
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General Meeting – December 2022
2022-12-09 19:30 - 21:00 | Irvine Lecture Hall of the Chapman University, 336 N Center St, Orange, CA, 92866, United States
This is a free and open to the public hybrid event, held both inperson and online. Due to the newly effective insurance requirements, we regret that we can not allow people under 18 on the Chapman Campus, they are welcome to attend online.
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The meeting is held at the Irvine Lecture Hall of the Chapman University, the exact street address can be found on the section above under “VENUE”.

The Voyager Spacecraft

Where they are, how they got there,

and where they are going

Twin Voyager spacecraft were launched in the summer of 1977 on a four-year mission to study Jupiter, Saturn and their natural satellites. A fortuitous option existed for one of them to continue on to Uranus five years later and Neptune after another three years. Space missions at the time were typically of days to months duration, and technology for even a four-year mission was considered pushing the limits of technology. A 12-year mission was seen as a pipe dream. But the Voyagers were outfitted with some new innovations, and techniques were developed in flight to make enhanced science possible at Uranus and Neptune if they should survive that long. The only thought given to a purpose beyond Neptune was in the form of a video record of sounds, music and greetings from the people of Earth to any intelligent beings that might happen upon the derelict remains of either craft somewhere in the cosmos. As the world has seen, expectations were exceeded beyond anyone’s imagination. The spacecraft are still operating well, with data being transmitted continuously and received daily.
This talk is intended to focus on the spacecraft technologies and highly creative techniques developed in flight, in the hands of a dedicated flight team, that allowed these intrepid explorers to extend their four-year prime mission to 45 years now, with the expectation of another possible five to ten years before they finally succumb to the inevitable loss of enough electrical power to keep them running.

Tim Hogle became hooked on astronomy at age 12 after building a 3″ Newtonian telescope and seeing Saturn with it in the dark skies of his front yard. These interests, astronomy and telescope making, have stayed with him ever since. After graduating in electrical engineering from Cal Poly San Luis Obispo in 1971, he joined the Navy Air Corps as a Naval Flight Officer for a few years, then left the Navy and serendipitously joined JPL and the Voyager flight team shortly after their launches; a dream opportunity to explore the solar system in a detail he never could through a telescope. This was so much fun that he accepted an offer to continue with the team to explore Uranus and Neptune.
Starting as a real time analyst, seeing the data coming in before anyone else saw it, he soon became the senior spacecraft systems engineer, responsible for a wide variety of duties including data and anomaly analysis, sequence, test, and contingency planning, and being involved in nearly all aspects of the mission. By the Neptune encounter, the Voyagers were as close as family members to him, and Tim wanted to continue using his years of experience to extend the mission as long as possible. His total time with Voyager was 27½ years. He has been retired since 2006, but kept in touch with former colleagues on the flight team to keep abreast of the progress of the Voyagers in his absence. In retirement, his astronomical interest has continued with visual observing at every opportunity, especially of faint galaxies through an 18″ telescope.
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General Meeting – January 2023
2023-01-13 19:30 - 21:30 | Irvine Lecture Hall of the Chapman University, 336 N Center St, Orange, CA, 92866, United States
This is a free and open to the public hybrid event, held both inperson and online. Due to the newly effective insurance requirements, we regret that we can not allow people under 18 on the Chapman Campus, they are welcome to attend online.
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COSMIC ARTIST:

THE WORK OF JON LOMBERG

Artist Jon Lomberg will talk about his long career working with Carl Sagan on projects like the Voyager Golden Record, the TV series COSMOS, and the movie CONTACT. He will also discuss work with Mauna Kea observatories and his creation of the Galaxy Garden, the worlds first scale model, walk through galaxy.

Jo Lomberg is one of the world’s most distinguished space artists. He was Designer of the Voyager Golden Record and Emmy-Award winning Chief Artist of Carl Sagan’s COSMOS series. He is a winner of the ASP’s Klumpke Roberts Award for astronomy popularization and has an asteroid named after him. He lives in Kona, Hawaii.

www.jonlomberg.com
www.galaxygarden.net

Special Offer
Jon is offering two of his best-known pieces with Carl Sagan, one from COSMOS and one from CONTACT at a special price of $60 (+$15 shipping) each. You can see the details of each by clicking on the respective words. These prints can be ordered directly from Jon at this special members price. Do not order through the website but send payment via PayPal to lomberg@aloha.net

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General Meeting – February 2023
2023-02-17 19:30 - 21:30 | Irvine Lecture Hall of the Chapman University, 336 N Center St, Orange, CA, 92866, United States
This is a free and open to the public hybrid event, held both inperson and online. Due to the newly effective insurance requirements, we regret that we can not allow people under 18 on the Chapman Campus, they are welcome to attend online.
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Puzzles in Galaxy Evolution

I will describe a pair of sharp puzzles suggesting a possible mismatch between our theory of galaxy evolution and recent observations from the James Webb Space Telescope (JWST). First, current models predict that most distant galaxies found by JWST should be seen at a time when they are transitioning from the initial assembly of their ingredients to the later processes by which they form stars, and other structures we recognize as a galaxy. Instead, fully-formed, massive galaxies appear to exist impossibly early, before their ingredients should even have been able to assemble. Second, a possible explanation for this would be that most galaxies grow very differently from the processes we have observed in star-forming regions of our own Milky Way. I will discuss whether such a difference might be able to reconcile both problems, or whether something is still “broken”.

Charles Steinhardt is an associate professor at the Cosmic Dawn Center and University of Copenhagen, having previously spent time at Caltech, Kavli IPMU, Harvard, and Princeton. His research is inspired by astrophysical phenomena whose explanation has been cast into doubt, either by new theoretical ideas or new observations. Recently, this includes several different areas of astronomy and astrophysics, including galaxy evolution, black hole accretion, and gamma-ray bursts. Recent work also includes developing machine learning and statistical methods for making full use of the large datasets modern astronomy produces. He also runs a summer undergraduate research program that brings American students to Copenhagen each summer.
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General Meeting – March 2023
2023-03-10 19:30 - 21:30 | Irvine Lecture Hall of the Chapman University, 336 N Center St, Orange, CA, 92866, United States
This is a free and open to the public hybrid event, held both inperson and online. Due to the newly effective insurance requirements, we regret that we can not allow people under 18 on the Chapman Campus, they are welcome to attend online.
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Hunting Isolated Black Holes

Black holes are fascinating, but enigmatic celestial objects. Long predicted by theory, as the product of some of the most energetic events in the universe, they have always presented severe challenges to observational astronomers. If the have a binary companion, accretion or the gravitational waves released during a merger can reveal their presence, but isolated black holes offer no such signatures. Yet understanding the Milky Way’s population of stellar remnants – both isolated and binary – will place important constraints on models of stellar evolution. The phenomenon of microlensing provides the means to detect massive objects, even when they emit no light at all. Modern surveys are capable of detecting these transient events across a huge swathe of the Galaxy, and will chart the population of stellar remnants in the Milky Way. This talk will explore how black holes fit into our understanding of the lives of massive stars, how microlensing can reveal even singleton stellar remnants, and describe how recent work has confirmed the first such discovery.
More on microlensing: http://www.microlensing-source.org/

Dr. Rachel Street completed her Ph.D. at the University of St. Andrews in Scotland, where her thesis focused on searching for exoplanets in open clusters. This work led to her first post-doctoral position at Queen’s University Belfast, Northern Ireland, where she was a founder member of the SuperWASP transit survey, for which she received the RAS Group Achievement Award and a PPARC Postdoctoral Fellowship. Rachel considers herself fortunate to have joined Las Cumbres Observatory (LCO), soon after it was founded, giving her the opportunity to watch the LCO Telescope Network develop into full operation. Rachel started to study first exoplanets and later stellar remnants through the phenomenon of microlensing using LCO’s telescopes, and she now leads the LCO Microlensing group as a Senior Scientist. Rachel recently stepped down as a co-chair of the Rubin Observatory Transients and Variable Stars Science Collaboration, which aims to prepare for groundbreaking science with the Legacy Survey of Space and Time.

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General Meeting – April 2023
2023-04-14 19:30 - 21:30 | Irvine Lecture Hall of the Chapman University, 336 N Center St, Orange, CA, 92866, United States
This is a free and open to the public hybrid event, held both inperson and online. Due to the newly effective insurance requirements, we regret that we can not allow people under 18 on the Chapman Campus, they are welcome to attend online.
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Observing the universe in the Ultraviolet

Prof. Hamden is a telescope builder, with a focus on UV astronomy and developing new detector technology. She will describe why the UV is so interesting scientifically and why is it criminally understudied. She will also discuss her own work on several different UV missions in development, including FIREBall-2 and Aspera.

Dr. Erika Hamden is a professor of astrophysics at the University of Arizona. She specializes in building telescopes that go into space and the stratosphere, and developing technology to make telescopes better. Erika is a leader in the field of space astrophysics, and has developed programs to teach early career scientists how to develop their own space missions. She is the deputy principal investigator of Aspera, a NASA orbiting telescope in development. She is a former chef, a TED Fellow, a AAAS If/then Ambassador, an aspiring astronaut, and is working on her pilots license.
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General Meeting – May 2023
2023-05-12 19:30 - 21:30 | Irvine Lecture Hall of the Chapman University, 336 N Center St, Orange, CA, 92866, United States
This is a free and open to the public hybrid event, held both inperson and online. Due to the newly effective insurance requirements, we regret that we can not allow people under 18 on the Chapman Campus, they are welcome to attend online.
Join Zoom

The Mystery Behind the Origin of

Radio Filaments in our Milky Way Galaxy

The Galactic center is an active region of our Milky Way Galaxy. There is a supermassive black hole at the center of the Galaxy.
Beyond its sphere of influence, there is a rich environment revealing relic of past activities of the black hole.
As part of an international team, observations with the new South African MeerKAT observatory has discovered hundreds of
magnetized thread-like filaments in the inner 1000 light years of the region surrounding the black hole at the Galactic center. These filaments appear
harp-like, commentary tail-like, or loop-like structures. After a brief history of the discovery of radio filaments in
the 80’s, the nature and origin of these structures will be discussed with an emphasis of why it is so puzzling
to understand their origin.

F. Zadeh received his PhD in Astronomy from Columbia University in 1986 before he went to NASA/Goddard Space Flight center as a National Research Council postdoc. He then joined the department of physics and astronomy at Northwestern University in 1989 and has been there since. His research interests are the black hole at the center of the Galaxy, star formation and cosmic-ray physics.
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General Meeting – June 2023
2023-06-09 19:30 - 21:30 | Irvine Lecture Hall of the Chapman University, 336 N Center St, Orange, CA, 92866, United States
This is a free and open to the public hybrid event, held both inperson and online. Due to the newly effective insurance requirements, we regret that we can not allow people under 18 on the Chapman Campus, they are welcome to attend online.
Join Zoom

Throwing DART(s) at Asteroids

NASA’s First Planetary Defense Mission

On September 26, 2022, NASA intentionally smashed the DART spacecraft into an asteroid as humanity’s first test mission for planetary defense. The Double Asteroid Redirection Test (DART) spacecraft’s collision with its target asteroid, which poses no threat to Earth, changed the asteroid’s motion in a way that can be measured using ground-based telescopes, including those of Las Cumbres Observatory.

In this talk, Dr. Tim Lister will describe near-Earth asteroids, impact hazards, and what the DART mission will do to prepare for potentially deflecting asteroids in the future.

Dr Tim Lister joined Las Cumbres Observatory (LCO) as a project scientist in 2007 and is now a Staff Scientist. He specializes in the observation and characterization of small Solar System bodies, particularly comets and Near Earth Asteroids. He received a M. Sci in Astrophysics from the University of St Andrews in 1997 and a Doctorate in Astrophysics on the study of magnetic activity on variable stars in 2000, also from the University of St Andrews. Following his doctorate, he was a founding member of the
SuperWASP transit survey searching for extrasolar planets, specializing in building data processing pipelines for analyzing the survey data, for which he received the RAS Group Achievement Award. Since joining LCO, he has worked on building pipelines and data archives for the observatory, confirming new transiting extrasolar planets and building a new science group for the study of Solar System objects. In the course of this research, he has developed web-based software to allow the scheduling and analysis of observations of Solar System objects using the telescopes of the LCO Network. He is currently Co-lead of the LCO Outbursting Objects Key (LOOK) Project to study the behavior of comets for ESA’s Comet Interceptor mission and a member of NASA’s Double Asteroid Redirection Test (DART) Investigation Team.
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