Hi everyone,
We are excited to announce the release of Astro-COLIBRI v2.31.0! This is one of our largest updates so far. Astro-COLIBRI now reaches you on your home screen, publishes its own real-time alert stream over Kafka, and brings the long-term gamma-ray light curves of the Fermi-LAT catalog into the app. On top of that, poorly localised alerts became a lot easier to work with, and the search for the host galaxy of a transient was rebuilt from the ground up.
Here are the highlights of this version:
Home screen widgets for Android and iOS: the transient sky at a glance, without opening the app.
The Astro-COLIBRI Kafka broker: subscribe to our machine-readable alert stream in JSON or VOEvent format and react the moment we do.
Fermi-LAT Light Curve Repository: long-term light curves of more than 1500 4FGL sources, one tap from the source.
Cone searches over the full localisation region: for gravitational waves, Fermi-GBM, IceCube and MAXI, instead of a fixed circle.
Long-term visibility: darkness, moonlight and observation windows for any period up to a year at your observatory.
Reworked galaxy cross-match: GLADE+, the DESI Legacy Surveys and SDSS quasars, with image cutouts and results per catalog.
New and improved alert streams: MAXI/GSC X-ray transients, gravitational waves via the GCN JSON format.
NMMA model comparison: fit and rank up to 16 supernova and kilonova models on the same event.
We describe the main new features in more detail in the replies below. The complete changelog is on our release history page.
As always, this update also includes a range of smaller improvements and bug fixes.
We look forward to hearing your feedback!
Clear skies,
The Astro-COLIBRI Team
Home screen widgets for Android and iOS
Astro-COLIBRI now lives on your home screen: keep an eye on the transient sky without even opening the app. Four widgets are available now, with more to come.
- Astro-COLIBRI gives an overview of the last 24 hours with a breakdown per event type, covering the events that match your filters.
- Latest discoveries shows every new event in the sky, marking the ones that match your own filters.
- Observable tonight lists what is up at your observatory, with each target’s visibility window and peak altitude.
- Watchlist keeps the events you saved in view.
A few things worth knowing:
- Every widget comes in several sizes, from a single box to a full-height list, and each size shows what actually fits rather than a cropped version of the same layout.
- On iOS the widgets are also available on the Lock Screen.
- Tapping an event opens it right away in Astro-COLIBRI. Latest discoveries and Observable tonight also give direct access to the AR sky view.
- Widgets follow your colour theme, including the red night-vision theme, and your app language.
- The content refreshes roughly every 30 minutes and requires a verified Astro-COLIBRI account.
Add them from your device home screen as usual. The Home screen widgets entry in your account menu explains what each one does and when it was last refreshed.
The Astro-COLIBRI Kafka broker
Astro-COLIBRI now publishes its own alert stream, so can receive machine readable alerts from all our sources (incl. GCN, TNS, CBAT, etc.) and your pipeline can react to an event the moment Astro-COLIBRI does, instead of polling the API.
Available topics
| Topic |
Format |
astrocolibri.all.JSON |
JSON |
astrocolibri.all.VOEvent |
VOEvent / XML |
astrocolibri.important.JSON |
JSON |
astrocolibri.important.VOEvent |
VOEvent / XML |
astrocolibri.heartbeat |
JSON |
Every alert is published in both formats, so subscribe to the one you already work with rather than to both.
- The important topics carry every newly detected event plus the updates that change the science of one: a refined localisation, a new classification, a measured redshift.
- The all topics publish the complete record, including the routine metadata updates.
- Alerts stay on the broker for 24 hours over a TLS-encrypted and authenticated connection, and your read position is remembered, so a client that restarts picks up where it left off.
Getting started
The Python client is one command away:
pip install astro-colibri
from astrocolibri import Consumer
with Consumer(
username="your-username",
password="your-password",
) as consumer:
consumer.subscribe(["astrocolibri.all.JSON"])
for message in consumer.consume(timeout=30):
print(message.value())
Alerts are also available as canonical IVOA VOEvent v2.0 objects, and any Kafka client in any language works just as well if you prefer your own stack.
Create your credentials with Request broker access in the Astro-COLIBRI menu. Everything else, including the consumer-group rules and the full Consumer reference, is on the new broker documentation page.
The Fermi-LAT Light Curve Repository, inside Astro-COLIBRI
Long-term gamma-ray light curves of more than 1500 sources of the Fermi-LAT 4FGL catalog, from 100 MeV to 100 GeV, are now available directly inside Astro-COLIBRI. The data come from the Fermi-LAT Light Curve Repository (Abdollahi et al. 2023).
- Where to find it: one tap from any Fermi 4FGL catalog source, and from the FLaapLUC alerts associated with one. Try it on 4FGL J0538.8-4405.
- Configure the query: choose the binning (3-day, weekly or monthly), photon or energy flux, a fixed or free photon index, and the minimum test statistic.
- Explore interactively: click a data point to see its date and flux and how it ranks against the full history, or click a bin of the flux histogram to highlight everything it contains.
- Quality flags: upper limits, outliers and points close to the Sun are flagged, and can be hidden or removed from the export.
- Export: download exactly the selected data, as CSV or IVOA VOTable.
- API: the same query is available through our API (cf.
/fermi_lcr), which returns the cleaned and flagged data points and upper limits as JSON together with a validation figure.
Full details on the Fermi-LAT LCR documentation page.
Working with poorly localised alerts
Two changes that mostly matter for gravitational waves, Fermi-GBM bursts and IceCube neutrinos.
Cone searches now cover the full localisation region
- For events with an extended sky localisation (gravitational waves, Fermi-GBM, IceCube, MAXI), the search runs inside the full 90% localisation region instead of a simple circle. Events without such a localisation keep the standard 10° circular search.
- The searched region can be enlarged directly on the sky map with a small margin control (−/+ in 1° steps, up to 20° around the contour).
- Also available through the API via the extended
/cone_search endpoint.
Long-term visibility of any source at your observatory
- A new interactive plot shows darkness, moonlight and daytime windows for any period up to a year, replacing the static, external image we used before.
- Selecting a night opens its detailed daily visibility view.
- Timetables can be copied or exported as ASCII, CSV or JSON.
The host-galaxy cross-match, rebuilt
The search for the host galaxy of a transient now queries an updated set of catalogs and presents its results per catalog.
New catalogs
- GLADE+ replaces GLADE v2.3: 22.5 million galaxies all-sky, with distances, stellar masses and a per-galaxy binary-neutron-star merger rate (VII/291).
- DESI Legacy Surveys DR8 photometric redshifts: 1.6 billion sources, the best chance of finding a faint host (VII/292).
- SDSS DR16 quasars: 750,000 spectroscopically confirmed quasars (VII/289). A match here suggests the transient sits on an active nucleus rather than in an ordinary host galaxy.
- PGC / HyperLEDA, 2MRS and the 2MASS extended source catalog remain available, and any VizieR table can be queried by name.
What you see
- A summary of the closest informative match, with separation, redshift, distance and projected offset in kiloparsecs.
- Sortable columns carrying their units, redshift uncertainties, and a show all columns switch for the rest.
- Direct links per match to SIMBAD, NED, VizieR, the Legacy Survey viewer and Aladin. The Aladin link opens with both the transient and the galaxy marked, named and colour-coded.
- An image cutout for every match, with the transient’s position and localisation uncertainty marked and the catalog source at the centre. Clicking it opens the usual image viewer for downloading and sharing.
New and improved alert streams
MAXI/GSC X-ray transients
Unknown X-ray transients detected by the MAXI/GSC instrument on the ISS are now ingested and shown as events.
- They join the Other high-energy observatory filter group and carry their own markers.
- The localisation uncertainty is drawn on the sky map, whether the error region is circular, elliptical or rectangular.
- When a GCN circular later identifies the source, the event is automatically renamed and reclassified, for instance to a gamma-ray burst.
- Notifications go to the Burst stream, and to the GRB stream once a circular identifies the event as a gamma-ray burst.
Gravitational waves
- The parsing of LIGO/Virgo/KAGRA alerts switched to the GCN JSON notice format.
- VOEvent downloads remain available: Astro-COLIBRI reconstructs a VOEvent in the familiar LVK layout. They are of course also available through our new broker (see above).
- Sky maps are archived in Astro-COLIBRI’s own storage, so localisations stay available independently of GraceDB.
- Alerts coincident with an external detection now name the reporting observatory, the type of the coincident event and the time difference between the two.
Fermi and FLaapLUC
GeV flares from AGN found by FLaapLUC are now part of the Fermi observatory. FLaapLUC analyses Fermi-LAT data, so its alerts are Fermi events with the instrument LAT-FLaapLUC, selected through a FLaapLUC sub-filter of the Fermi observatory filter instead of the separate FLaapLUC entry.
Modelling, catalogs and smaller improvements
NMMA: comparing several models at once
The light-curve fitting introduced in v2.29.0 grew a comparison mode.
- Fit up to 16 models on the same event in a single request and rank them by Bayesian evidence (log Bayes factor), with dedicated overlay light-curve and corner plots.
- Five kilonova models joined the eleven supernova templates, and the fits now run on NMMA 1.1.0. Existing fits were re-processed with the new version.
- The service is described in detail in W. Kiendrébéogo et al., NMMA - Astro-COLIBRI: An Automated Light-Curve Supernovae Classification Service in the Multi-Survey Era, submitted (arXiv:2608.17568).
Catalogs
- Updated TeVCat copy: 337 sources, 21 more than before, with increased redshift coverage, distances in kiloparsecs for Galactic sources, and more precise source classes.
- New figures for Fermi-LAT 4FGL sources: a flux vs. spectral index figure like the one for TeVCat, and a combined figure with the spectral energy distribution from 50 MeV to 1 TeV next to the 14-year yearly light curve, showing at a glance whether a source is steady or flaring. All catalog figures load about three times faster.
- More precise classes and filters: 4FGL now distinguishes BL Lacs, FSRQs and blazar candidates instead of grouping them as AGN, and TeVCat has dedicated sub-filters for shell-type supernova remnants, pulsars, superbubbles and massive star clusters.
General filters now work in cone searches
Catalog sources (4FGL, TeVCat, X-ray binaries, IceCube IceCat neutrinos) stay in cone-search results unless they genuinely fail a criterion, and the general sub-filters can be used to refine those results. As a reminder, the general filters apply on top of the event-type and observatory filters and let you select by visibility from your observatory, distance to the Sun, alert broker, follow-up program, and whether retracted events are shown.
And a few more
- The AI-assisted extraction of follow-up observations from GCN circulars is now an open-source Python package, astro-colibri-circular-parser, described in F. Schüssler et al., AI-Assisted Extraction of Follow-up Observations from GCN Circulars in Astro-COLIBRI, submitted (SciX).
- GRB optical afterglows: the archival comparison sample was updated to include three additional catalogues, now shows upper limits correctly, and the brightness extrapolation can be configured for a selected filter band.
- The last modified time of an event now changes only when its core information actually changes, not when metadata such as image URLs or photometry is refreshed.
- Watchlist events can be removed from the list of displayed events.
- Updated access to solar activity data from NOAA.
Reminder to save the date: the 5th Astro-COLIBRI Multi-Messenger Astrophysics Workshop takes place October 12-16, 2026 at Paris-Saclay, France.
