Uploaded May 2020 | Updated September 2026, 2 weeks ago
Instructeur de AAVSO CHOICE: Jean-Bruno Desrosiers
AAVSO HQ
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CHOICE en français: Classification des Étoiles Variables et Courbes de Lumière, chapitre 1
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![AAVSO How to [image star guts with cosmic music]](https://i.ytimg.com/vi/aKtQcmRtYzI/mqdefault.jpg "AAVSO How to [image star guts with cosmic music]
Originally broadcast April 2, 2022
Jim Fuller (CalTech) instructs this AAVSO How-to session
What lies at the center of a star? A stellar core is surrounded by a million Earths worth of plasma, so we cannot see it directly. However, the immense power of a star’s radiation causes nearly all stars to pulsate, creating “star quakes” at their surfaces. These oscillations are a collection of musical notes that uniquely define each star and are determined by its internal structure, just as the sound of a musical instrument is determined by its size and shape. Join us for a cosmic symphony as we journey to the center of the Sun, Saturn, white dwarfs, red giants, and heartbeat stars.
Fuller is an assistant professor in theoretical astrophysics at the California Institute of Technology. He uses asteroseismology to study the structure and evolution of all types of stars, including Sun-like stars, red giants, massive stars, white dwarfs, and even the planet Saturn.
Interested in attending a live (on Zoom) 2022 How-to session? aavso.org/2022-how-to-hours
Explore all the opportunities to make a real contribution to science with AAVSO, an international scientific and educational nonprofit: aavso.org/welcome")
![AAVSO How to [Count Sunspot Activity]](https://i.ytimg.com/vi/aeYM3WVCxc8/mqdefault.jpg "AAVSO How to [Count Sunspot Activity]
With instructor: Dr. Kristine Larsen (Central Connecticut State University)
Original broadcast date August 6, 2022. At the time of the broadcast, the closest variable star, our sun, has begun to awaken from solar minimum, presenting observers with an ever-changing constellation of sunspots and other features. Following up on her popular 2021 webinar on how to safely observe the sun*, Dr. Kristine Larsen returns to share the ins and outs of sunspot monitoring. Measuring sunspot activity takes more finesse than merely counting the total number of spots. Learn about the care and feeding of sunspot groups, and the important role they play in measuring solar activity.
Dr. Larsen is an astronomy professor at Central Connecticut State University. Her teaching and research focus on the intersections between science and society, including Gender and Science, science and popular culture (especially science in the works of J.R.R. Tolkien), and the history of science. She has received numerous awards, and has authored several books.
* 2021 webinar on how to safely observe the sun: https://www.youtube.com/watch?v=Vh3FakqfbPQ&list=PLnZ_rvnR35re3ZxnumCnIesanWvUyy9eB&index=3")
![AAVSO How to [Observe Optical Counterparts of High Energy Astronomical Transients]](https://i.ytimg.com/vi/bQfXWKMjWkc/mqdefault.jpg "AAVSO How to [Observe Optical Counterparts of High Energy Astronomical Transients]
Originally broadcast Feb. 5, 2022. In AAVSOs first How-to Hour of 2022, Heinz-Bernd Eggenstein leads us. He is an AAVSO observer and co-lead of AAVSOs High Energy Network Observing Section.
Heinz-Bernd focuses on discussing the observation of three of the most energetic and interesting phenomena in the universe: the Gamma-Ray-Burst (GRB) and its optical afterglow, the Binary Neutron Star (BNS) Merger resulting in a “kilonova,” and the Core-Collapse Supernova (and here specifically the next such event in our own galaxy).
At first glance, none of these three event classes seem to be well suited for the amateur astronomer because their first signals reaching us can only be seen by professional observatories: the Earth’s atmosphere shields us against gamma rays, so Gamma Ray Bursts are typically detected by satellites like FERMI and SWIFT. Binary Neutron Star Mergers so far can only be detected with high confidence by huge gravitational wave observatories. And, perhaps somewhat surprisingly, the very first signal of the next galactic core collapse supernova will actually be a burst of neutrinos, minutes to hours before the optical supernova signal can be seen.
However, in all three cases, professional astronomers broadcast “alerts” of such events through channels that are now available to the public, some more well known than others. We discuss how amateurs can use these channels and join professional-amateur collaboration projects to make meaningful observations of these most fascinating events. While observing these transients remains challenging for various reasons, being prepared for “target of opportunity” observations should be a skill that can be rewarded by outstanding and important amateur observations.
Interested in AAVSO? visit aavso.org
Interested in our HEN observing section? aavso.org/aavso-international-high-energy-network")
