Astro-COLIBRI

Astro-COLIBRI combines an application programming interface (API), a static and a real-time database, a cloud-based alert system, and a website and apps for iOS and Android. The clients show a graphical summary of the relevant data so that interesting phenomena can be identified quickly, together with an assessment of the observing conditions at a large selection of observatories around the world. With direct access to many external services, Astro-COLIBRI is a central point for information about astrophysical sources and transient events.

To meet the needs of real-time observations, the clients are built with the open-source framework Flutter, which provides the same interface on every platform, including mobile devices.

Astro-COLIBRI shows each event against historical data and other transients, on the timescale relevant for its category. A cone search around the event lists known sources and recent transients, and the localisation uncertainty is drawn on the sky.

Coordinating follow-up observations also means knowing who can observe what, and when. Astro-COLIBRI shows the short- and long-term visibility of events from all major observatories or any custom location: source altitude, Sun and Moon altitude, Moon phase and Moon–source separation. Exact observing conditions, including observations under moonlight, are implemented for selected observatories, and a link to ESA's TOBY tool gives the visibility and schedule of space observatories such as INTEGRAL, Gaia, Chandra, Insight-HXMT, XMM-Newton and Swift.

Astro-COLIBRI is free for professional and amateur astronomers, and burst advocates at several observatories (H.E.S.S., the LST-1 telescope of CTAO, SVOM and others) use it regularly. Version 2.0 of the web interface, released in August 2022, is described in the Galaxies paper; examples of use are given in F. Schüssler et al., PoS(ICRC2021) 935.

The website is at astro-colibri.com, and the apps are on Google Play and the App Store. Tutorials are on our YouTube channel, and discussions take place on the forum.

In early 2026 we added a fundamentally new interface to Astro-COLIBRI: the transient sky can now be explored in augmented reality, overlaid on the real sky through the camera of a phone.