[Click here for the October–December schedule and webinar registration links]
Gary Billings, "Information from Periodic Star Light Curves" Many variable stars exhibit their variability in repeating, or approximately repeating, cycles of brightness variation—they are periodic. This talk will present the basics of looking at regular periodic phenomena, and is intended to set the stage for the subsequent talk about O-C diagrams, where we will look at some of the ways that a star's behavior might vary from a constant period. These talks will focus on simple calculations involving a star's period and period changes, not the astrophysical causes of the period changes. While the principles apply to other types of stars, eclipsing binary stars will be used as examples.
George Silvis, "Using AAVSO's Exoplanet Database for Reporting and Retrieving Exoplanet Observations" Silvis volunteers with AAVSO, dedicating much of his time and expertise to our databases and software. If you want to learn how to submit your exoplanet observations to our database, or use any of the observations stored in the database for your research, this is the webinar for you!
François Cochard, "New to Spectroscopy? A few tips to start successfully"
Spectroscopy is the study of electromagnetic radiation wavelengths, each of which is emitted by an object or produced through an object’s interaction with other matter. In spectroscopy, a spectrum is a range of light separated into different wavelengths, each which projects a unique brightness. Observing stellar spectra can answer questions poised in human minds since our collective eyes first gazed starward. Beginner to experienced spectroscopists are encouraged to submit data to AAVSO's spectroscopy database, AVSpec. You can observe crucial data and uploaded to AVSpec with or without high-tech equipment. If you want to get started in spectroscopy, join in this webinar, complete with an audience (that's you!)-driven Q&A.
Cochard organizes the Spectro Star Party every year at the Observatoire de Haute Provence (OHP), assisting a lot of observers in their first steps in spectroscopy, so his instruction is a great place to begin your spectroscopy journey (or even figure out if spectroascopy is right for you)!
Gary Billings, "Eclipsing Binaries and O-C Diagrams" A continuation of Billings's September How-to Hour, "Information from Periodic Star Light Curves," (slide deck also available), where we will now look at some of the ways that a star's behavior might vary from a constant period. Both of his talks focus on simple calculations involving a star's period and period changes, not the astrophysical causes of the period changes. While the principles apply to other types of stars, eclipsing binary stars are used as examples.
Dr. Emily Levesque, "Betelgeuse Is Pretty Cool: Cosmic Questions for our Naked-Eye Neighbor" Betelgeuse's "Great Dimming" in the winter of 2020 quickly became a source of fascination for both professional and amateur astronomers. Drastic enough to be easily detected with the naked eye, the star's drop in brightness was unprecedented in observational memory, and revealed the extent to which the workings of red supergiants (RSGs) are still a mystery. RSGs are the coldest and physically-largest members of the massive star population, making them ideal sources for studying the extremes of stellar physics, and a key turning point in the evolution of post-main-sequence massive stars. They are also the progenitors of Type II-P supernovae, an intermediate evolutionary phase in the lifetimes of some stripped-envelope supernova progenitors, and a crucial step in the formation of massive binary systems (including those that will ultimately produce compact object binaries and gravitational waves). However, our recent studies of Betelgeuse have forced us to confront the many unanswered questions that still surround RSGs, including their binary fraction and evolution, their place in the larger picture of massive star evolution, and the numerous physical phenomena that drive their variability. Using Betelgeuse and its recent behavior as an archetype, this talk will provide an overview of our current knowledge of RSGs, identify some of the most pressing open questions about these stars, and consider the importance of studying RSGs in the coming decade as the next generation of observatories comes online.
Dariusz Kubicki, "International Observation Campaign of Eclipse of EE Cephei in 2020" In January 2020, we announced an international observation campaign. Over 50 observers from all over the world responded to our appeal, mainly from North America and Europe. Observations were carried out using the Johnson BVRI and Johnson-Cousins RcIc systems. During the campaign, TB, TG, and TR photo filters present in the Bayer mask in cameras were also used. A large number of observations were made by amateur astronomy enthusiasts. Although burdened with large dispersion, they give excellent coverage of light curves of both the eclipse and the brightening of the star in phase 0.2. To verify the correctness of photometry from amateur telescopes, data obtained from Mount Suhora Observatory were used. Pioneering polarimetric observations using the Savart Plates in R filter were made. They provided information about the change in total polarization and the light polarization angle of EE Cep. The observations were carried out over the course of a year and a half, including the eclipse and the brightening.
Dr. Nancy Morrison, "How To Write an Astronomical Research Paper" The presentation will be designed so that writers at all levels can take away valuable principles. It will include discussion and examples of how to: know and write for your audience, write an abstract, organize a research report by section, organize your ideas within each section, cover elementary concepts, support your points with citations, make a literature search with the ADS and with SIMBAD, support your points with figures and tables, design figures, write table and figure captions, construct a citation list, and revise your manuscript. A revision exercise will be provided as "homework."
Stay tuned for November and December!
Past 2021 webinars
Dr. Matthew Kenworthy, "Shadows of Circumplanetary Disks: J1407 and J0600" Planets form in the disks surrounding very young stars, and the planets themselves will have a smaller disk around them in which moons will form. These circumplanetary disks are hundreds of times larger than Saturn's rings and when they transit in front of their parent stars, the transits can last hundreds of days, with individual ring structures causing fluctuations on timescales of one day or less. The AAVSO has proved crucial in monitoring several stars in which we believe we are seeing circumplanetary disk transits. From the star J1407 and its eclipses in 2007, through to the current monitoring campaign of J0600, I'll show what we can discover through multiband light curves and what we hope to see in the next few years.
Dr. Hans Moritz Günther, "Variability in young stars: From the AAVSO to X-rays" While our Sun is almost 5 billion years old, stars still form in the the dark clouds of our Milky Way. When we observe those regions we can learn how star and planet formation works, so that we also understand the formation of our own solar system and the Earth better. I will show how we can use variability on many different time scales from hours to centuries to understand how young stars work. How do they accrete mass? How do their proto-planetary disks evolve? Do proto-planets ever crah into the stars? I will look at several specific stars such as RW Aur and T Tau, the star that named the group of T Tauri stars, and describe our observations including X-rays, UV, and optical data. In most cases, no one observation alone can tell us what's happening on the star; only when we combine observations from the Chandra X-ray observatory, the Hubble Space Telescope, and AAVSO data we can learn about the physics of star formation. For a few examples, I will explain how observations on space telescopes are allocated and planned, and why the generous and flexible support by AAVSO observers is so crucial to our observing programs. Star formation is a very active area of research with many open questions to solve and certainly one of the areas in astronomy that delivers extremely beautiful images of the Milky Way that surrounds us.
Melanie Crowson, "Study of and Reclassification Evidence For Four Candidate RR Lyraes - TY Cam, V0363 Dra, NSV 13109, V1386 Aql" RR Lyrae stars have been an important aspect of studying stellar evolution since their discovery in the early 20th century and are now frequently used for distance measurements in the universe. The purpose of this research is to examine four RR Lyraes, two confirmed and two candidates, in an attempt to determine their periodicities and assess their classifications. RR Lyraes TY Cam, and V0363 Dra, as well as candidates NSV 13109 and V1386 Aql were chosen for this project, and were all studied using the American Public University’s (APU) 24 inch CDK telescope and the NKAF observatory, along with the ASAS-SN and SuperWASP archives. This study determined the most likely periods of TY Cam and V0363 Dra, and sided with the reclassification suggestion by ASAS-SN for NSV 13109 as an L class, irregular variable. For V1386 Aql it was found that much inaccurate data has been collected on this star due to its proximity to a brighter companion; however it appears to be a promising variable candidate, but requires more precision photometry to solidify its classification. Future research by APU will include such observations on this challenging, potential variable.
Dr. Sarah Antier,"Kilonova-catcher project at GRANDMA and how AAVSO observers can help" Diverse messengers - photons and gravitational waves - provide a new picture of the collision of two neutron stars. In this talk, I will first review briefly how coherent analysis of the messengers can not only better constrain the astrophysical scenarios at play, but also further knowledge on the cosmology and fundamental physics side. In a second part, I will present the Global Rapid Advanced Network Devoted to the Multi-messenger Addicts, which aims to identify and characterize the optical counterparts of gravitational-wave sources. As a third part, I will describe how you can, as an amateur astronomer, join the project and participate in the observations of neutron star mergers.
Dennis Conti, AAVSO Exoplanet Observing Section, "Using AstroImageJ for Exoplanet Analysis" This webinar will include a step-by-step walkthrough of using the AstroImageJ freeware for the reduction, differential photometry, modeling, and overall analysis of exoplanet observations.
Dr. Luisa Rebull, "Stellar Rotation in Young Clusters using K2 and TESS" K2 has provided a phenomenal opportunity to study properties of stars in clusters, particularly young low-mass stars, far beyond the expectations of the original Kepler mission. The high-precision photometry provided by K2 allows us to probe stellar variability to lower masses and lower amplitudes than has ever been done before. Younger stars are generally more rapidly rotating and have larger star spots than older stars of similar masses, so spots rotating into and out of view reveal the (surface) rotation rate of these stars. K2 has monitored stars from several clusters, most notably Rho Oph (~1 Myr), Taurus (~5 Myr), USco (~20 Myr), the Pleiades (~125 Myr), and Praesepe (~700 Myr). The light curves have yielded thousands of rotation rates, and revealed far greater diversity in light curves than was anticipated. Now that we have TESS data as well, we can add the Upper Centaurus-Lupus (UCL) and Lower Centaurus-Crux (LCC) young moving groups (~15 Myr). In this talk, I will review the K2 results and present early results from UCL/LCC.
Dr. Margarita Karovska, "Why is it important to observe/monitor LPVs?" Long Period Variables (LPVs) are evolved stars (cool giants and supergiants) that show significant variations (including photometric, spectral, and variations of other physical characteristics) on time scales ranging from days to many years, even centuries (as shown for example by the AAVSO long term monitoring of their light curves). Some of these stars show regular periodic brightness changes due to pulsation, in some cases few magnitudes over hundreds of days (e.g., Miras). Longer secondary periods have also been observed, on the order of thousands of days, with the causes still not clearly identified. Among the LPVs there are stars that show irregular variations, and the causes of this variability have not yet been determined. A number of LPVs have a companion star, including an evolved compact white dwarf accreting mass from the powerful wind of the cool giant or supergiant.
Based on many years of multi-mission, multi-wavelength studies of these incredibly interesting sources, including high-angular resolution studies using ground- and space-based observations, I can summarize the results with three words: fascinating, unexpected, and surprising! The seemingly regular behavior of many LPVs is anything but that--when studied on a longer time scale of years!
I will highlight some recent results with emphasis on the critical role of the AAVSO long term LPV observing/monitoring in enabling these discoveries and on the potential for many future discoveries.
Dr. Barbara Harris, "How to Do Variable Star Photometry With Your DSLR" Many astronomers have a DSLR and use it for general photography and astrophotography. I would like to encourage you to use your DSLR to contribute to science by measuring the brightness of variable stars.
Dr. Steve Howell, "Using AAVSO photometry to understand and characterize variable giant stars" During a multi-year campaign, the AAVSO provided multi-color photometry to complement optical spectroscopy in an attempt to understand a number of long-standing misunderstood complexities and characteristics in a set of variable giant and supergiant stars. This talk will review the observations and how they have been fit together to formulate new insights into such stars. A few particularly interesting examples will be highlighted.
Dr. Juan Echevarría, "Spectroscopic and photometric observations of the intermediate polar DW Cnc" Spectroscopy and photometric observations of the DW Cnc interactive binary will be shown during a low state and the beginning of a return to a high state: we will see that the signal from the spin of the white dwarf (38 min.), as well as the beat period signal (69 min.), were both absent, and mostly the power spectra showed the orbital period frequency (86 min.). On the way to the high state, we will start to see the former signals, but they are still not of the strength of the observations made around 1999-2003 by Patterson et al. (2004) and Rodriguez-Gil et al. (2004).
Dr. David Whelan, "Classifying Algol C, the Non-Eclipsing Member of the beta Persei System" For nearly a century it has been known that there are at least three stars in the Algol system: two (A and B ) in a close eclipsing binary, and a third (C) orbiting the binary at a much greater distance. But tension has existed as to Algol C's precise spectral type. Some scientists claim that it is a normal A- or F-type star, while others state that it must be an Am star. Using low-resolution spectra suitable for spectral classification, we have observed the Algol system at numerous phase angles, including primary and secondary eclipse, and have scaled and subtracted two of our spectra to create a spectrum for Algol C that allows us to recommend for it a precise spectral type. We will discuss our method, which is accessible to anyone with a suitable spectrograph. We will analyze our result to determine whether it can be deemed "correct." And if we are correct, then we will have definitively answered one of the many long-standing questions of astrophysical importance that lie hidden in plain sight, among the brightest stars in the sky.
Lauren Herrington, "Spectrography on a Budget" Spectrography has long been seen as a difficult and expensive pursuit, but it really doesn't have to be! The march of technological progress has brought about low-read-noise CMOS cameras, powerful computers, and inexpensive diffraction gratings, all of which help make it possible to record high quality stellar spectra without using a tracking mount at all.
I will reveal how you can use the "drift scanning method" to record scientifically useful spectra of tens of thousands of stars using nothing but a camera, diffraction grating, and an untracked telescope. I will also discuss how to optimize your resolution, so that you can use your slitless grating to record fine details, such as the blueshifted absorption lines originating in the torrential stellar wind of P Cygni. Lastly, I will demonstrate how to process and calibrate your spectra, and how to submit your processed spectra to the AAVSO's database.
No prior knowledge is necessary, but attendees will likely find it beneficial to know ahead of time what the terms "spectrum," "absorption," and "emission" mean as they relate to astronomy, and how to operate a simple telescope. Recommended pre-How-to Hour reading: http://spiff.rit.edu/classes/phys301/lectures/spec_lines/spec_lines.html.
AAVSO's Short Period Pulsator (SPP) Observing Section, "SPP Observing Section Webinar" The webinar begins with an introduction by SPP observing section leader Eric Hintz (5 minutes), and is followed by Jarrod Hansen discussing using short period variables to teach research to undergraduate students (25 minutes). Marcelo Bighetti will then speak on development of a high school competition based on short period pulsating stars (25 minutes). Hintz will wrap up the presentation by discussing testing automated variable star period determinations for SPP stars (40 minutes).
Using short period variables to teach research to undergraduate students: Over many years, SPP variables have been used as one of the targets for an observational astronomy class at Brigham Young University. The final goal of this class is to generate publication-quality papers from data taken in class and from online archives. As the class has evolved, the expectation levels have gone up. The current state of what the students can do with SPP variables will be discussed.
Development of a high school competition based on short period pulsating stars: SPP stars and other variables provide ideal targets for young observers. A short study showed that many junior high and high school-age students think astronomers basically run star parties. There is a need to change this perception, and SPP variables provide an ideal tool. An idea for high school competition using data on SPP stars will be presented. This is still in the early development phase, but we hope to have a test program with a small group of schools next school year. Once piloted, plans include having AAVSO observers help school groups get even larger data sets.
Testing automated variable star period determinations for SPP stars: Observers can contribute even if they only have a couple hours in a night to work. We have used SPP variables for many years to teach research methods to our astronomy majors at BYU. The students can see clear variations in a single night and can most likely get entire cycles of the light curve. In the current epoch of astronomy there are a large number of programs that find new variable stars, such as TESS, KELT, ATLAS, ASSN, and in the future, LSST. We have searched these databases for potential new targets for extensive study using our group of 6 robotic campus telescopes. However, the number of potential variables is far more than even 6 telescopes can handle. We hope to make a list of targets available to AAVSO observers that covers both hemispheres, over the entire year, and over a range of magnitudes. The majority of these objects do not appear in previous variable star catalogs, and most don't have an entry in SIMBAD. This is a chance to help establish the true nature of these objects, even if you only have a few hours.
Dr. Adam Burgasser, "Stormy with a Chance of Iron: Weather and the Dynamic Atmospheres of Cold Stars and Brown Dwarfs" The lowest-mass fusing stars and non-fusing brown dwarfs have atmospheres that are cool enough to form clouds of liquid and solid condensates. However, unlike our beautiful water vapor clouds on earth, these clouds are made of molten iron, rock snow, and sulfide sleet. In this talk, I discuss how we know about the existence of these clouds, both from theory and observation, and how these clouds are used to study rotation and 3D atmospheric structure, and even find binary brown dwarfs.
Dr. Boris Gänsicke, "The end of the worlds" We now know that it is totally normal for stars to have planets, and the variety and complexity of observed exo-planetary systems is continuously growing. One question that then arises: what is the ultimate fate of these planetary systems? And what is the fate of our solar system? Once the planet host stars run out of fuel, they will become red giants, shedding a fraction of their mass, and leaving their burnt-out, Earth-sized cores behind (white dwarfs). Recent years have seen a rapidly growing number of observations that show that many planets or their remains survive the metamorphosis of their host stars, and now orbit the slowly cooling embers of stellar evolution. I will review how we can identify such evolved planetary systems via the detection of planetary debris contaminating the atmospheres of white dwarfs--debris causing rapidly evolving photometric transits, and discuss the detections of giant planets on close orbits around white dwarfs.
Bob Buchheim, "How to start with CCD photometry" CCD astro-imaging can make beautiful pictures and very accurate measurements of the objects in your field. This workshop is aimed at the person who is curious about the “measurement” aspect of CCD imaging. I will introduce the concept of stellar photometry, some differences in imaging techniques when your goal is “measurement” vs. “beauty,” and suggestions for your first few variable star activities. No experience in CCD imaging is required to join this session, but a little bit of knowledge will be helpful. The goal is to help you experience variable star measurement for yourself, so you can decide if it is an activity that you enjoy.
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). I will review 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, "Spectroscopy: which hardware for which observations?" We'll 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 spectro---but some are easier and some less so. This presentation will mainly be dedicated to newcomers to spectroscopy, and you can attend even with no experience---just curiosity!
Trevor Dorn-Wallenstein, "Solving the Red Supergiant Problem with a New Class of Pulsators" Massive stars drive the radiative, chemical, and kinematic evolution of their host galaxies. Despite the importance of these stars, the physical factors that govern their progression through the exotic evolved states that we observe them in are poorly understood, and every new observational advance seems to raise more questions than it answers. In particular, there is a mismatch between the masses of stars we expect to explode as supernovae, and the red supergiant stars we have witnessed undergoing this cataclysmic event—a discrepancy known as the red supergiant problem. One potential solution? If the most massive and luminous red supergiants shed enough of their envelopes before the ends of their lives, they explode as yellow or blue supergiants instead. While finding genuine post-red supergiants is difficult, discovering the lowest mass star that undergoes this phenomenon would place stringent constraints on the evolution and final fates of massive stars. In this talk, I will highlight the discovery of a new class of pulsators called “fast yellow pulsating supergiants” (FYPS) that may be genuine post-red supergiant objects. I will discuss the context surrounding this discovery, as well as the scientific avenues that FYPS may let us explore. Finally, I will demonstrate how observations from AAVSO observers can enable similar discoveries.
Dr. Burçin Mutlu-Pakdil, "The Faintest and Smallest Galaxies" around the Milky Way are the most ancient, most metal-poor, and most dark-matter-dominated systems known. These extreme objects offer unique access to small scales where the stellar and dark matter content can be studied simultaneously and hold the promise of major breakthroughs in understanding the nature of dark matter, and a more complete picture of galaxy formation. Thus, their discovery and characterization are among the most important goals in the field. I will share our ongoing observational efforts to detect these faint systems around the Milky Way and beyond, and upcoming advances in the era of deep and wide imaging instrumentation.
Richard Berry, "Your First Observatory: Keep It Simple!" Your first observatory should be inexpensive, simple, and easy to use. Its purpose: to be the place you call your own, offering minimal set-up time and maximal convenience. For example, a simple L-shaped fence can shelter you from wind and stray light, while a small concrete pad with an electric outlet can make set up fast and the alignment accurate. After getting started with a simple observatory, you can build on the experience as you plan a fancier shelter, roll-off roof, or domed observatory.
Dr. Dan Milisavljevic of the Supernova Early Warning System (SNEWS) Team, "Observing the Next Galactic Supernova: Will you be ready?" The catastrophic deaths of massive stars--supernova explosions--are among the most powerful and important events in the cosmos. Supernovae strongly shape the structure and chemistry of their host galaxies; they produce a variety of exotic objects including neutron stars, black holes, and gamma-ray bursts; and, perhaps most importantly, supernova debris ejected into interstellar space is chock full of the heavy elements that make planets and life possible. Dr. Milisavljevic will provide a vivid description of historical supernovae that occurred in our own Milky Way galaxy, and outline plans for a coordinated global response to the next "Big One." Particular emphasis will be drawn to the special role that AAVSO members will have in responding to an alert from the Supernova Early Warning System (SNEWS), which is a network of neutrino detectors around the world designed to rapidly provide the first announcement when the next once-in-a-century Galactic supernova occurs.
Tom Calderwood, "A Romp with Betelgeuse" The dramatic fade-out of alpha Orion in 2019-2020 was of major interest to professional and amateur astronomers alike, and scientists are still trying to sort out what happened. We will review the research results for this extraordinary event and highlight AAVSO's photometry of the red star in the giant's left shoulder.
Sebastián Otero, "A Quick Guide on VSX" A large number of observers worldwide find AAVSO's Variable Star Index (VSX) as the most practical venue to share their discoveries with the world. And people everywhere search VSX for the latest information on their favorite variable stars. But some may still find it hard to use, or may not be aware of some options, features, and resources that can be found in VSX. This will be a practical guide to show you how to use the VSX search options, how to submit your new discoveries and how to revise the information on existing objects.
Dr. Sanlyn Buxner, "Celebrating Amateur Astronomers Engaging in Exploration, Outreach, and Research" Astronomy continues to capture the imagination of individuals across the world. Public engagement is supported and facilitated by a large community of amateur astronomers who not only engage in their personal interests, but provide outreach and engage in important research activities. This talk will highlight the importance of the work done by volunteers of the AAVSO and other organizations, through interviews with 53 individuals from across the spectrum of amateur astronomy. The findings reveal the complexity of how amateur astronomers engage as independent explorers, outreach agents, and researchers. This talk will also include a discussion about how the field is working to enhance diversity, and innovations that occurred as a result of the worldwide lockdown due to COVID.
Dr. Kathy Vivas, "Las galaxias más pequeñas del Universo y sus estrellas variables" Los grandes sondeos digitales del cielo que se están realizando en la actualidad han permitido que en los últimos 5 años se duplicara el número conocido de galaxias satélites de la Vía Láctea. La mayoría de estas galaxias son enanas y muy poco luminosas y, por esas razones, se les llama galaxias enanas ultra-débiles. Estas galaxias no solo son las más pequeñas sino también las más comunes en el Universo y juegan un papel fundamental en la formación y evolución de estructuras en el Universo. La búsqueda de estrellas variables en esas diminutas galaxias permite conocer mas sobre la población estelar de esas galaxias y la distancia a la que se encuentran.
Ken Menzies, George Silvis, & Gary Walker "AAVSONet Proposals – What, Why and How?" and "Introduction to the Bright Spectral Robot." In this webinar with the Bright Star Monitor (BSM) Observing Section, AAVSONet Management Team leaders Ken Menzies and George Silvis will first discuss: "AAVSONet Proposals – What, Why and How?" You will learn how you can take some images using the AAVSONet Telescopes? A few simple answers will get you images in your VPhot account, that you can analyze and report to the AAVSO International Database(AID), and more.
Gary Walker (BSM systems engineer) will then introduce you to the Bright Spectral Robot: The success of the Bright Star Monitor is impressive, currently operating at 300,000 images annually, with a total since inception of nearly 2 million images. It has recently been updated with Epsilon 180 Astrographs and Paramounts. This project explores the possibility of doing similar work with spectroscopy. The advantages of clear weather, dark skies, and autonomous operation are well proven for photometry, and the author believes that the time is right to do the same for spectroscopy. The author has configured a system consisting of ZWO and SBIG sCMOS cameras, a Shelyak UVEX spectrometer, a PlaneWave CDK 14 optical tube,a Planewave L350 Mount with Hi Rez Encoders, which gives a platform that can do this task. This is a progress report to date.
John Toone, "Visual Photometry of Variable Stars" Visual photometry is the original method of recording changes within variable stars, and it is as important today as it was 150 years ago when it was the sole means of measuring variable stars. Toone's presentation will demonstrate the basic methodology, how it can be optimized, and explain the effects of color & the relationship with Johnson V, which is the equivalent electronic photometry passband. Toone will also introduce you to the world’s most prolific visual observers of variable stars.
Dr. Elmé Breedt, "The Gaia Science Alerts Transient Survey" Now in its eighth year in orbit, the European Space Agency's Gaia satellite has already had a transformational impact on astronomy. Apart from its main goal of creating a 3-dimensional map of the Milky Way, Gaia is also discovering thousands of new objects through its transient survey, known as Gaia Science Alerts. Dr. Breedt, who works on the Gaia Science Alerts project, will talk about what goes on behind the scenes to run a survey like this, and discuss some of the interesting transients observed so far.
Dr. Gibor Basri, "Information and Illusions in Starspot Light Curves" Brightness variations of stars have been known for centuries. Some of them are due to the passage of starspots over the visible hemisphere as stars rotate. In the past 15 years, we have been able to gather vastly better, longer, and more numerous light curves from space--especially from the Kepler mission. Starspots have various sizes, grow and decay with various timescales, and appear at various locations over time; their composite light curve also depends on the stellar inclination. Stars like the Sun show such chaotic light curves that it is hard to infer even the rotation periods. In (more variable) stars that show clear periods, most light curves are deceptively simple, with one or two dips per stellar rotation. This simplicity is mostly illusory; the true spot distributions can be quite complicated. That presents problems to making astrophysical conclusions about the starspots. I’ll discuss what we are learning and how stellar variability changes as a function of stellar mass and age.
Ana Parra, "Ana's Journey into Exoplanet Transit Analysis" How did I go from not knowing anything about Exoplanets, planets that exist outside our Solar System, to wanting to record an Exoplanet transit with my first telescope? My journey began with an Astronomy 101 course, a few amazing mentors, and an opportunity to do exoplanet transit research. Learning the history of Exoplanets was the jumping point to analyzing exoplanet transits with the TESS Follow-up Observing Program Sub-Group 1, mentoring Boyce-Astro students interested in Exoplanet research, and reaching out to my fellow AAVSO ambassadors for support in purchasing and operating my very first telescope. I will discuss how Exoplanets were discovered, how we benefited from Exoplanet research, and my involvement in Exoplanet transit research. I will also share how important it is to have mentors and to become a mentor.