ALeRCE Labs

ALeRCE Labs is a space for experimental tools, interfaces, and community-driven developments built around ALeRCE data and services. These projects are often created rapidly to explore new ideas, workflows, and ways of interacting with astronomical data.

While these tools are not part of the official ALeRCE production platform and may not undergo the same level of testing, they can provide valuable capabilities for researchers and the broader community. We also welcome contributions from community members and are happy to showcase tools that help expand the ALeRCE ecosystem.

ALeRCE Explorer

https://explorer-experiment.alerce.online
This project is an experimental, multi-survey explorer for ALeRCE that lets astronomers find and study transient and variable objects detected by survey telescopes — currently ZTF and the Vera Rubin Observatory (LSST). You search for objects by their machine-learning classification, probability, brightness history, detection count, or position on the sky, then open a single detail view that brings everything about a source together in one place: its light curve (with toggles for flux or magnitude, observed or extinction-corrected, apparent or absolute, and phase-folding), its difference/science/template images, an interactive sky viewer with redshift catalogs, classifier probabilities, a periodogram for finding periods, catalog crossmatches, and links out to other archives. The main users are astronomers and students working with ALeRCE alert streams who want one integrated tool for quickly characterizing and following up interesting objects. The key thing that sets it apart from the standard ALeRCE Explorer is that it is genuinely multi-survey: whenever you open an object, it automatically looks for the same source in the other survey at that sky position and overlays its data on the same light curve, images, and plots, so a source seen by both ZTF and Rubin is shown as a single combined object rather than two separate detections.

By Francisco Förster

ALeRCE Hunter

https://hunter-experiment.alerce.online
ALeRCE Hunter is a web application for discovering astronomical transients — exploding stars, variable objects, and other things that change in the night sky — in near real time. It connects to the ALeRCE broker, which processes the live alert streams from two major sky surveys: the Rubin Observatory (LSST) and the Zwicky Transient Facility (ZTF). You search for candidates by survey, object class, and filters like detection count, age, magnitude, and brightness band; results come back as a sortable table you can label as genuine candidates or bogus. For any object you can open a detailed view with its image stamps, an interactive light curve (how its brightness changes over time), a zoomable sky view, and full object metadata — plus an all-sky map showing every candidate at once and an airmass calculator to plan when and from which observatory a target is best observed. Results can be exported to CSV, and the tool is built
to work on both desktop and mobile.

By Francisco Förster

TNS Reporter

https://tns-experiment.alerce.online/

The ALeRCE TNS Pipeline is a web-based tool that streamlines the reporting of newly discovered supernova candidates to the Transient Name Server (TNS), the official IAU registry where astronomical transients are formally announced and named. Drawing on candidates flagged by ALeRCE’s machine-learning classifiers from the ZTF and Rubin/LSST sky surveys, it guides an astronomer through the full reporting journey in one place: reviewing and cleaning the night’s candidate list, vetoing any that look spurious, automatically identifying each transient’s likely host galaxy, cross-checking against objects already known to TNS (while still allowing genuinely independent detections from a different survey through), and finally assembling and submitting a properly formatted discovery report — with optional Slack and WhatsApp notifications to the team. Its main users are the ALeRCE astronomers responsible for the nightly supernova-reporting duty. The key difference from other ALeRCE tools — which focus on detecting and classifying transients, or on browsing the alert stream — is that this one sits at the very end of that chain: it takes the candidates ALeRCE has already found and handles the official act of reporting them to the world, replacing what used to be a slow, error-prone manual process spread across Python scripts, notebooks, spreadsheets, Slack, and the TNS website with a single, guided, semi-automated web application.

By Francisco Förster

ALeRCE Feature Explorer

https://fforster.github.io/experimental/feature-explorer/
The ALeRCE Feature Explorer is an interactive, browser-based tool that lets astronomers visually explore the physical and statistical “features” that the ALeRCE broker computes for the millions of changing objects (transients, variable stars, etc.) it monitors from the ZTF and LSST sky surveys. Instead of querying a database or writing code, a user picks a classifier and one or more object classes (say, supernovae or quasars) and the tool pulls a live sample straight
from ALeRCE‘s servers, then displays it as a pair plot or a UMAP map where each point is a real object. Clicking any point instantly reveals that object’s light curve and its position on the sky, so you can connect a pattern in the data to the actual astrophysical source behind it — and even overlay fitted physical models on the light curve. The main users are astronomers and students who want to understand and compare the features driving ALeRCE‘s classifications: to spot clusters, outliers, and class differences, sanity-check the data, or hunt for interesting objects. The key difference from other ALeRCE tools (like the main Explorer or the API) is its focus on feature-space visualization and discovery: rather than searching for or listing individual objects, it gives you a fast, exploratory, point-and-click overview of how whole populations of objects distribute across their measured properties, all in a single self-contained page with no installation.

By Francisco Förster