Uploaded May 2021 | Updated September 2026, 2 weeks ago
This webinar was originally broadcast on May 8, 2021, and features talks by two astronomy researchers:
First, Dr. Christian Knigge: "Cataclysmic Variables as Universal Accretion Laboratories." Cataclysmic variables (CVs) are numerous, bright, and nearby, making them excellent laboratories for the study of accretion physics. Since their accretion flows are unaffected by relativistic effects or ultra-strong magnetic fields, they provide a crucial "control" group for efforts to understand more complex/compact systems, such as accreting neutron stars (NSs) and black holes (BHs). He reviews recent work on CVs, which has revealed that these superficially simple systems actually exhibit the full range of accretion-related phenomenology seen in accreting NSs and BHs. Given this rich set of shared behavior, it is reasonable to hope that much of accretion physics is, in fact, universal.
François Cochard follows with "Spectroscopy: Which Hardware for Which Observations?" We look into what kind of hardware is required to start in spectroscopy, and the kind of observations we can make with it. There are a lot of things that we can do in spectroscopy---but some are easier and some less so. This presentation is mainly be dedicated to newcomers to spectroscopy, and no experience is necessary to benefit from this discussion--just curiosity.
Explore AAVSO and how YOU can make a valuable contribution to science by visiting us at aavso.org
This webinar was originally broadcast on May 8, 2021, and features talks by two astronomy researchers:
First, Dr. Christian Knigge: "Cataclysmic Variables as Universal Accretion Laboratories." Cataclysmic variables (CVs) are numerous, bright, and nearby, making them excellent laboratories for the study of accretion physics. Since their accretion flows are unaffected by relativistic effects or ultra-strong magnetic fields, they provide a crucial "control" group for efforts to understand more complex/compact systems, such as accreting neutron stars (NSs) and black holes (BHs). He reviews recent work on CVs, which has revealed that these superficially simple systems actually exhibit the full range of accretion-related phenomenology seen in accreting NSs and BHs. Given this rich set of shared behavior, it is reasonable to hope that much of accretion physics is, in fact, universal.
François Cochard follows with "Spectroscopy: Which Hardware for Which Observations?" We look into what kind of hardware is required to start in spectroscopy, and the kind of observations we can make with it. There are a lot of things that we can do in spectroscopy---but some are easier and some less so. This presentation is mainly be dedicated to newcomers to spectroscopy, and no experience is necessary to benefit from this discussion--just curiosity.
Explore AAVSO and how YOU can make a valuable contribution to science by visiting us at aavso.org





![AAVSO How to [Understand Star Photometry]
Originally broadcast March 5, 2022. Instructor: Richard Berry. Berry is well experienced in stellar photometry and was a programmer for the science-oriented software Astronomical Image Processing for Windows (AIP4Win).
Photometry seems like magic: you click on a star image and a magnitude pops up! But a lot happens between the moment you click and the moment that magnitude pops up on the computer screen. Berry explores with you in non-technical terms what the computer has to do to turn your pixels into meaningful information. This talk complements Bob Buchheims Introduction to Photometry 2021 webinar (https://www.youtube.com/watch?v=gcE7c4CggFM). Berry describes how to do photometry by presenting the inside picture of how photometry works and why it works so well. He demonstrates using AIP4Win software (join aip4win@groups.io to download this freeware package), but all stellar photometry software works pretty much the same way.
Interested in AAVSOs Instrumentation & Equipment Section led by Rich Berry? aavso.org/instrumentation-section
Interested in our other How-to Hours and webinars? aavso.org/programs-events
Visit us and learn how to make a meaningful contribution to science at aavso.org AAVSO How to [Understand Star Photometry]](https://i.ytimg.com/vi/ufbFaUywEBg/mqdefault.jpg)
![AAVSO How to [Think About Transformation]
with instructor Tom Calderwood. Originally broadcast June 4, 2022. Astronomers have spent decades defining photometric systems. Systems like Johnson-Cousins define a standard scale on which photometry from different observers can be directly compared. However, simply using a Johnson or Cousins filter does *not* put your magnitudes on the standard system. Your data require adjustment, and this step is known as transformation. In this discussion, Tom explains why transformations are necessary, and sketch out the basics of how their parameters are determined.
Tom Calderwood is head of the AAVSO Photoelectric Photometry Observing Section. He observes from Central Oregon, and is the author of The Great Dimming of Betelgeuse in the March 2021 issue of Sky & Telescope. A graduate of MIT in mathematics, he is a retired software engineer who worked on parallel processing computers, communication networks, video games, and the data system for the Chandra X-ray Observatory.
Interested in attending a free live How to [...] session? aavso.org/2022-how-to-hours
Want to learn more about photoelectric photometry (PEP)? AAVSO has an observing section full of people dedicated to it: https://www.aavso.org/aavso-photoelectric-photometry-pep-section
Check out all AAVSO has to offer you at aavso.org AAVSO How to [Think About Transformation]](https://i.ytimg.com/vi/urgkBDkiUEE/mqdefault.jpg)



