The American Association of Variable Star Observers (AAVSO) hosts several Special Interest Groups that focus on specific aspects of variable star astronomy. These groups bring together observers, researchers, and enthusiasts with common interests to share knowledge, collaborate on projects, and advance citizen science in astronomy.
Our Special Interest Groups welcome members of all experience levels, from beginners to advanced observers. Each group provides resources, tutorials, observing campaigns, and a community of supportive members to help you develop your skills and contribute meaningful astronomical data.
Below you’ll find our current Special Interest Groups. Feel free to explore and join any that match your interests.
Exploring the night sky through a global network of telescopes—bringing remote observing to every AAVSO member What We Do AAVSOnet is a collection of telescopes located around the world, operated and maintained by a dedicated volunteer team of AAVSO members.
Monitoring nature’s fireworks—the explosive science of stellar remnants. What We Do Cataclysmic Variables (CVs) are interacting binary systems where a white dwarf accretes material from a companion star. This process produces dramatic variability: dwarf nova outbursts, classical novae, and other
Dimming Stars that enlighten our understanding of stellar evolution What We Do Eclipsing binaries are pairs of stars whose orbital plane is aligned so that, from Earth, one star passes in front of the other, causing periodic dips in brightness.
Exploring distant worlds—detecting and monitoring exoplanets through long-term transit observations. What We Do Exoplanets are planets orbiting stars beyond our Solar System. By observing the slight dips in a star’s brightness as a planet transits (passes in front of it),
Watching the universe’s most extreme explosions—monitoring optical counterparts of gamma-ray bursts, X-ray binaries, blazars, and other high‑energy phenomena. What We Do The AAVSO International High Energy Network is dedicated to the optical monitoring of high-energy astrophysical phenomena in the universe.
Building the tools of discovery—developing, using, and improving telescopes, photometers, spectrographs, and all gear that enables observational astronomy. What We Do The Instrumentation & Equipment Section is the central hub for discussing, learning about, and innovating in the hardware and
Tracking the slow, grand changes of giants—observing Miras, semi‑regulars, RV Tauri, and irregular long‑period variable stars. What We Do Long Period Variables (LPVs) are pulsating red giant and supergiant stars, that provide fascinating insights into the inner workings of stellar
Measuring the lives of the brightest variable stars. What We Do While CCD cameras have revolutionized amateur photometry, camera systems struggle with very bright stars like Betelgeuse. AAVSO PEP concentrates on stars brighter than magnitude 6 using instruments known as
Exploring the heartbeat of stars—measuring rapid pulsations in Cepheids, RR Lyrae, δ Scuti, and other short‑period variable stars. What We Do Short period pulsators (SPPs) are stars whose brightness varies due to internal pulsations, caused by a variety of factors including
Counting magnetic maelstroms—unraveling the Sun’s mysteries through long-term monitoring of sunspots. What We Do The Sun is the nearest star to Earth. As our stellar neighbor, it’s the first that comes to mind—and the standard by which astronomers measure all
A rainbow of potential—capturing and analyzing the spectra of variable stars to understand their physical properties and processes. What We Do The AAVSO Spectroscopy Special Interest Group promotes and advances astronomical spectroscopy for observers at all skill levels. We help
Probing the birth of stars—observing the chaotic, dynamic light of pre–main sequence stars (YSOs) to understand stellar formation and early evolution. To begin with, it is known that many stars listed in the GCVS of type I are seriously underobserved.
