What we learn from studying variable stars.
Variable stars are vital for understanding the life cycle of stars, for getting distances to faraway galaxies, and for uncovering exoplanets orbiting stars.
Wednesdays: Oct. 18, 25; Nov. 1, 2023. 7-9 PM online.
Reduced tuition- $35 AAA members/ $45 non-members.
Our instructors are from AAVSO, the American Association of Visible Star Observers
AAVSO, is a major resource for training amateur observers and linking them to professional astronomers. It is a large organization that has extended its roots in variable stars to other aspects of modern astronomy, such as exoplanets, spectroscopy, photometry, supernovae light curves, solar physics. It does so via journals, workshops, mentoring, networking, conferences, and with 12 focused research sections. It maintains an extensive, well-organized website: AAVSO.org.
AAA members should know about the AAVSO. Some may want to avail themselves of its events, resources, workshops, and its website. Some already have.
Light curves of variable stars reveal much.
Oct. 18- Brian Kloppenborg, AAVSO Executive Director.
AAVSO is a 112-year-old non-profit whose mission is to enable anyone, anywhere, to participate in scientific discovery through variable star astronomy. We achieve this by teaching amateur astronomers how to conduct variable star observations; collecting, reviewing, and disseminating data; establishing collaborations with professional astronomers and observatories; and promoting citizen science.
I will introduce the AAVSO by discussing its history, resources, offerings, and contributions to science with examples from the work of our members.
I am an astrophysicist and entrepreneur with a Ph.D. in Physics from the University of Denver, and a B.A. in Physics from Hastings College. Previously I worked as a Research Scientist at Georgia Tech Research Institute as a subject matter expert, lead engineer, product owner and businessman, and project director on a variety of government programs. My research includes photometry, spectroscopy, astrometry, and long-baseline optical interferometry of eclipsing binaries, novae, and young stellar objects. This work has been published in Nature, ApJ, JAAVSO, and other journals.
Oct. 25- Dennis Conti, Chair of Exoplanet section and AAVSO Board Member
Exoplanets (planets outside our solar system) come in all sizes, compositions, and orbital configurations around their host star. Some are even free floating! Our overall
knowledge of these distant and strange worlds has grown exponentially, with amateur astronomers, working side-by-side with professional astronomers.
This lecture will review some of the many types of exoplanets discovered so far, how and why the transit method is the dominant method of exoplanet discovery, what some of the
challenges are in discovering exoplanets, and how observations by amateur astronomers have been essential.
I am a retired telecommunications professional and an amateur astronomer with a strong interest in exoplanet research. In 2015, I founded the AAVSO’s Exoplanet Section which works closely with the TESS Science Team to qualify AAVSO members as participants in the ground-based follow-up program. Over 26 AAVSO members now part of that program. This required forming TESS submission guidelines and the software for detecting false positives, both of which have benefited the entire TESS team.
I’m co-author of over 50 exoplanet discovery papers, including a recent publication in Nature, and have presented at conferences and local astronomy clubs, as well as teaching online exoplanet courses. I was honored by the American Astronomical Society’s 2020 Chambliss Amateur Astronomy Achievement Award.
Nov. 1- Ken Menzies, Instructor and Associate Leader of AAVSONet Section, which manages remote telescopes.
I suspect most of you know what a variable star is. It changes its apparent brightness over time, as
observed from our point of view. When and how a massive spheroidal body of plasma (hot, ionized gas)
emits more or less radiation during its lifetime from birth to death is caused by external and internal
processes that are defined by surrounding conditions and/or internal structure that change over a
period of up to 10 trillion years!
While most stars may appear stable over perhaps 90% of their lifetime, that additional 10% of life (birth,
old age, or death) exhibits many surprises! We’ll review these external conditions (stellar nursery or
binary companion), or internal structure (shells/layers of different composition) and the impact they
have on the brightness variation over both short and long timeframes. These lightcurves are the key to
identifying the many types of variable stars that we enjoy observing and investigating.
Subsequently, we will discuss the best practices to use to reliably observe a star’s fluctuation in visible
light and measure a star’s magnitude which can be displayed in a light curve.
I have been a variable star observer since my teens in the 60’s. I started with visual observing in Cambridge MA, that was supported by Margaret Mayall (Director) at the nearby AAVSO HQ. More recently, CCD observation from my roll-off roof observatory has facilitated active observing of short period pulsators and cataclysmic variables. I’m active in AAVSO as an Associate Leader and an observer and facilitated the Choice Course entitled “Photometry using Vphot”.
In Tribute: Dr. Leavitt’s work on variable stars was the key to determining distances to galaxies.
A bonus for those who register:
Your receipt will contain the link to the Google Classroom. Click that to be put on the class roster. Posted in that “GC” is a link to a recording of a recent class by Bart Fried (V.P. of AAA) on binary stars. A special extra to supplement the topics to be covered by AAVSO.
