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.
This section grew out of the AAVSO International Gamma-Ray Burst (GRB) Network, which had a lot of success detecting and following up on the optical afterglows of GRBs. Observers around the world are ready to respond quickly to alerts from satellites, giving amateurs the chance to image these fleeting, rapidly fading events.
Today, HEN is broader: in addition to GRBs, we monitor blazars and Active Galactic Nuclei (AGN), Galactic gamma-ray sources (like X-ray binaries), and other high-energy phenomena. We also aim to support multi-messenger sources, including optical follow-up of gravitational wave events and other transient high-energy triggers.
Our network is truly international: observers worldwide collaborate in follow-up campaigns, contributing vital data to scientific research.
How We Do It
When a high-energy event is reported (for example, a GRB detection by a satellite), alerts are distributed via the Gamma-ray Burst Coordinates Network (GCN). Observers with suitable telescopes and CCD equipment can rapidly respond, image the field, and attempt to catch optical afterglows or transient behavior.
These observations are typically done with CCD cameras, using standard or specialized filters, depending on the target and the science goals. Data are reduced (e.g. photometry) and sent to the AAVS International Database (AID), where they can be used for light‑curve construction, analysis, and publication. We maintain detailed guides, tools, and procedures to help observers participate effectively.
Is It Right for Me?
Level: Challenging. Observing high-energy targets often requires fast response, experience with CCD photometry, and an understanding of transient-source behavior.
Equipment: A telescope (size can vary) with a CCD camera, sometimes with filters optimized for faint transient detection. Access to a system that can respond quickly to alerts is very helpful.
Observing Requirements: Observers may need to monitor on short notice (within minutes to hours) when alerts are issued. Observing sessions vary: GRB afterglows fade quickly, while blazars or AGN might require long-term monitoring.
Additional Considerations: Observers should be familiar with data reduction software (photometry), comfortable with rapid, sometimes unpredictable observing schedules, and able to submit data via AAVSO tools. Participation often involves working within a global, collaborative campaign structure.