Past Guest Speakers

The SJAA has enjoyed presenting these notable individuals as guest lecturers during our general meetings.

May 6th, 2017
Lena Heffern, NASC
Title: Gamma-Ray Spectrometers for Use in Planetary Sciences
Description: Gamma-ray spectroscopy is a well-known technique used in measuring planetary elemental composition, a key to understanding planet formation and evolution. Orbital gamma-ray measurements have already been done on Mercury, the Moon, asteroids, and Mars. However, due to the need for a low-resource (power, mass) instrument, few surface measurements have been made using gamma-ray spectroscopy, especially at high resolution. The development of a new high-purity germanium (HPGe) gamma-ray spectrometer (GRS), called the GeMini-Plus, is currently underway and will allow for high-resolution, laboratory quality measurements to be made in both orbital and landed missions. This talk will focus on both the GeMini Plus and the Psyche gamma ray spectrometer. I will present the instrument designs and capabilities, including the science for characterizing surface compositions on Psyche, Titan, and the Martian moons Phobos and Deimos.

April 8th, 2017
Dr. Gibor Basri
Title: The Role of Magnetic Fields in the Lives of Stars
Description: Magnetic fields are pervasive in the Universe, and often have very noticeable and important effects on astrophysical phenomena. In particular, essentially all stars are magnetic at some level, and magnetic fields begin to play a role even before the star is born. Young stars are much more active than our Sun today, although solar magnetism has various effects on both the Sun and the Earth. Finally, magnetic fields can also play an important role in the death of stars. I’ll take you on a tour of the role magnetic fields play in stars of different masses and ages, with particular attention to our Sun.

March 11th, 2017
Dr. Peter Jenniskens, SETI
Title: Dance of streams
Description: Astronomers are engaged in far reaching surveys of stars and galaxies, mapping ever larger objects in the universe. Closer to home, the Bay Area is part of a very different type of survey: a night-time surveillance of the night sky to map out our meteor showers throughout the year. Meteor astronomer Dr. Peter Jenniskens of the SETI Institute and NASA Ames Research Center will present the fruit of that labor to date: a movie that shows the dance of meteoroid streams from night to night in the ever changing gravity field of the planets. The observations are occasionally punctuated by unexpected new showers, shower outbursts, and the occasional meteorite fall or satellite reentry. Jenniskens will explain how these maps have given astronomers new insight into the nature of the zodiacal cloud.

January 14th, 2017
Donald Gardner, Ph.D.
Title: Solar Eclipses from the North Pole to the Equator and Next Up:USA
Description: There are two to five solar eclipses every year, but total solar eclipses occur on average only once every 18 months. In addition, totality occurs only in a narrow path on the surface of the Earth, so totality reoccurs at any given place only once approximately every 400 years on the average. The last two total eclipses were challenging to see because they were at extreme locations on the Earth at the North Pole and at the equator. The next time the moon casts a shadow however will be here on August 21, 2017 where it will be racing across the United States from Oregon to South Carolina. The most dramatic features of an eclipse occur only during totality which include viewing the chromosphere, the corona, Baily’s beads, the diamond ring, shadow bands, and a” 360 degrees sunset”. Totality however is something that has to be experienced to be fully understood. In this presentation, images and video taken from the icy glaciers of Svalbard and from the volcanic islands of Indonesia will be shared followed by a discussion of the upcoming eclipse in America. One needs to be in the 70 mile wide path to experience the most amazing and awe inspiring aspects of totality. Strategies for how to view this upcoming eclipse, safety precautions, and best places to go will be reviewed.

November 12th, 2016
Dr. Jeff Moore
Title: New Horizons, NASA’s Pluto-Kuiper Belt Mission
Description: In 2006, NASA dispatched an ambassador to the planetary frontier, The New Horizons spacecraft. After 10 years and more than 3 billion miles, on a historic voyage that has already taken it over the storms and around the moons of Jupiter, New Horizons has shed light on new kinds of worlds on the outskirts of the solar system. On July 14, 2015, New Horizons flew 12,500 km (7,800 mi) above the surface of Pluto and continues into unexplained territory, as just the fifth probe to traverse interplanetary space so far from the sun and the first ever to travel to Pluto.

October 15th, 2016
Dr. Yashar Hezaveh
Title: Unveiling the Dark Universe: A Tale of Fish Tanks, Wine Glasses, and the Smallest Dark Matter Clumps
Description: What is “dark matter?” This is a question that has preoccupied astrophysicists for many decades. Observations show that 80% of the matter in our universe is in this mysterious, invisible form. In this talk, I will discuss how we use ALMA, the world’s most sophisticated radio telescope, to observe some of the most distant galaxies of our universe to learn new things about dark matter. On their 12 billion light year journey to us, light rays from these galaxies pass near other galaxies. As this happens, the dark matter halos of the intervening galaxies, large and small, bend their trajectories, causing the images here on the Earth to look distorted, like images in a funhouse mirror.

September 17th, 2016
Mr. Don Machholz
Title: Messier Marathon
Description:The talk will be about the Messier Marathon and how to run it. We begin with a short overview of the life of Charles Messier, a comet hunter who developed the list of objects. We then move on to the actual Messier Objects in Messier’s Catalogues. Some of the Messier Objects have been missing or misidentified, and we will take a few minutes to cover the “lost” objects. An overview of the Messier Marathon follows, with tips on making it a successful night. Finally, using maps of the sky showing all of the Messier Objects, we take a walk through the objects, one by one, showing how to find each of the objects and the purpose of the observing order.

August 20, 2016
Dr. Amy Furniss
Title: The Violent Universe Observed with the Fermi Telescope
Description: The Fermi Gamma-ray Space Telescope was launched into space in June 2008. The main instrument is the Large Area Telescope (LAT). Dr. Amy Furniss will present the Fermi-LAT instrument and highlight its most interesting results after seven years of operation.Gamma-ray observations open a new window into the universe, allowing us the study of exotic and violent processes. These photons are also an important tool in the search for the dark matter that pervades the universe. One expected signal is gamma rays from annihilations of massive dark matter particles, and the LAT has made by far the most sensitive searches for this process. The high-energy sky seen by the Fermi-LAT is quite dynamic, including explosions of massive stars and their remnants and supermassive black holes in the centers of distant galaxies. The Fermi-LAT also enabled the identification of many cosmic particle accelerators, including supernova remnants and active galactic nuclei, which are far more powerful than the largest particle accelerator on Earth, the Large Hadron Collider in Europe.

June 18th, 2016
Francesca Fornasini
Title: Hunting for Black Holes in High-Mass X-ray Binaries
Description: Not only are black holes fascinating objects in and of themselves because of their extreme gravitational fields, but they are also important pieces in the puzzles of how massive stars and whole galaxies evolve.  A better understanding of the stellar black hole population can shed light on key outstanding questions about stellar and galaxy evolution, such as:  How much material do massive stars lose before exploding as supernovae?  What fraction of massive stars that explode leave behind a black hole?  When and how quickly did early galaxies re-ionize the hydrogen gas in the intergalactic medium?  What factors determine how many stars a galaxy produces over time? I will discuss my ongoing work to find and study black holes in high-mass X-ray binaries, binary systems consisting of a black hole or neutron star accreting matter from a massive stellar companion, and how this work will help answer some of these broader questions.

21 May, 2016
Dr. David Clark
Title: The Beautiful Shapes of Planetary Nebulae and Theories About Their Formation
Description: Planetary nebulae are formed when a small-to-medium mass star dies and puffs its outer atmosphere into space. Their many varied shapes are beautiful, ranging from bubbles, to rings, to bipolar lobes. Some have high velocity jets. In this talk I will discuss three planetary nebulae: NGC 6751, NGC 7026, and Hb 12. NGC 6751 consists of multiple shells and a bipolar outflow. NGC 7026 is an intricate, multi-polar planetary nebula with X-ray emission. Hb 12 is a gorgeous, hourglass planetary nebula with a tight waist. The data for NGC 6751 and NGC 7026 were acquired using the Manchester Echelle Spectrometer at San Pedro Matir Observatory in Baja California, Mexico. The data for Hb 12 were acquired using the integral field spectrograph NIFS on Gemini North. The analysis for NGC 6751 and NGC 7026 was done using the modeling program Shape. I will present the analysis for each object and then compare and contrast the findings.

23 April, 2016
Dr. Chris McKay
Title: Recent results from Enceladus and the NASA Ocean Worlds Program
Description: From Cassini we are learning more about the inside ocean on Enceladus and everything we learn further indicates habitability. At the behest of Congress NASA has now started an Ocean Worlds program. A New Frontiers mission to Enceladus is one of the candidate missions. Life in the sea of Enceladus.

9 April, 2016
Dr. Sukanya Chakrabarti
Title: Hunting for Dark Matter Using Galaxy Quakes
Description: Dark matter is believed to pervade our universe, but there are few ways to find and understand this mysterious stuff that does not emit any light. I will review how the astronomical community first inferred the existence of dark matter and the current methods used to search for it. My own work in understanding dark matter is similar to the hunt for planets in the 1800s. I use a dynamical analysis to infer properties of dark-matter dominated dwarf galaxies from studying the gravitational tides they raise on galactic disks. We now have evidence that this method, that we call Galactoseismology (or analyzing Galaxy quakes), gives us a new way to hunt for the darkest galaxies and understand how dark matter is distributed in galaxies like our own.

23 January, 2016
Mr. Donald Gardner
Title: Solar Eclipse in Svalbard
Description: The speaker will share his experiences during his trip to Svalbard, Norway to view the March 20, 2015 solar eclipse.
Some info on the eclipse is here.

29 August, 2015
Mr. Jim van Nuland
Title: Weather or Not
Description: Every time we amateur astronomers plan to go out with our scopes we face the same question: What will the conditions be like? Our very own Jim van Nuland will present his experiences on predicting the weather and making the call whether or not to go out or not. Following his presentation, we’ll hold an open discussion and invite everyone to ask questions and share experiences.

29 May 2015
Mr. Michael Packer
Title: Cracking Globular Clusters
Description: The 160 spherical oceans of stars we call globular clusters (GCs) need aperture, good seeing and dark skies to resolve detail. But once observed to their core CG’s can reveal a exquisitely rich sea of red giant and fuel spent stars that do not take us back to the big bang but rather show us time in its extreme. Michael’s talk will spell out the general properties GC’s and which ones to observe/image for detail. He will also cover GC formation with some N-particle animation and the role GCs play in the new field of galactic archeology.

2 May 2015
Mr. Curtis Macchioni
Title: An Introduction to Deep Sky Video Astronomy
Description: Video astronomy is no longer just for the planets, the moon and the sun. Today’s astro-video cameras can easily reach down to 18th magnitude or lower and bring up dramatic color views of galaxies, nebulae, star clusters and many other deep sky objects. No longer do you need to stare at a faint fuzzy image of a distant galaxy in your eyepiece. With a video camera costing less than a good eyepiece, you can view dust lanes and globular clusters on the screen of your TV with ease.
I will show you images taken from my back yard in Livermore, as well as, images taken at CalStar and GSSP of a variety of DSOs using several different cameras and scopes. I will review and show you many of the available video cameras and their different features from a $35 DIY camera to a $1800 top of the line camera. I will discuss the advantages of video, show the equipment needed to get started and provide an in-door demonstration with a camera and small scope.
Hopefully, you will learn why so many are now turning to video to re-energize their interest in astronomy and you will see how video is a great tool for public outreach. You will even learn how to use video astronomy as an easy and inexpensive way to get started in astrophotography.

April 2015
Mr. Brian Kruse, Bay Area Project ASTRO
Mr. David Prosper, NASA Night Sky Network
TitleProject ASTRO and the NASA Night Sky Network
Description: There are two things amateur astronomers like to do best: look at objects in the night sky through their telescopes, and share their enthusiasm and views through their telescopes with others. The second activity frequently takes place at public star parties, or at a school-based event for teachers and students. Two programs at the Astronomical Society of the Pacific are specifically designed to help build the capacity of amateur astronomers and their clubs to engage in effective outreach at these events.
Founded in 1993, Project ASTRO partners volunteer astronomers with classroom teachers, bringing the wonders of the universe to thousands of students in classrooms throughout the Bay Area every year.
Managed by the ASP for NASA, the NASA Night Sky Network has for over ten years developed toolkits of essential resources to assist amateur astronomy clubs in engaging the public in astronomy.
These two programs complement each other, helping astronomers develop the skills and have access to the resources needed to effectively reach out to their community. Astronomers from SJAA have participated in Project ASTRO, and utilized toolkits from the Night Sky Network. This evening find out more about these two programs, and how you can get involved.

January 2015
Mr. Andrew Bell
Title: Seeing Double
Description: Double stars are often quite pretty to look at. And we don’t need dark-sky sites or moonless nights to enjoy looking for them. Close pairs (or more distant but “unequal” pairs) can afford good tests of our eyes, our optics, and our seeing conditions. Much of our modern understanding of stellar populations and stellar evolution has been gleaned from careful observations of close binaries and small multiple-star systems.
I will talk a little bit about how double stars are catalogued, describe good resources for finding useful double star information (both printed and electronic), and then discuss some of what has been learned from the study of visual double stars and small star systems. A handout will be provided, with charts and data for several dozen nice winter season “challenge objects” for double star observations.

2011-2014    2007-2010