Transient Explorer

What am I looking at?

Every night the Rubin (LSST) and ZTF telescopes image the sky and flag anything that changed since last time: a supernova going off, a star flaring, an asteroid passing through. Each flag is an alert. The Fink broker classifies them, and this site shows what they are and where. Transients the two surveys miss, reported by others to the Transient Name Server, are here too.

Sources

  • ZTF and Rubin: objects the surveys alerted on. Each detection is an alert, with the broker's classification, a reliability score and three image cutouts.
  • TNS: transients reported to the Transient Name Server that neither survey alerted on, among them nearly every bright one south of −30°, which ZTF cannot see. Each detection is a report: the magnitudes reported to TNS (the discovery, and any later ones), each in its reporter's filter, then ATLAS's measurements (c and o bands) for two months while it is brighter than 19. Reported by names the surveys (ATLAS, GOTO, Pan-STARRS, …). When ZTF or Rubin later alerts on one, it becomes their object.
  • CBAT: reports on the Central Bureau's Transient Object Confirmation Page that neither the surveys nor TNS have, mostly bright Galactic novae (PNV J…) and dwarf novae in outburst (TCP J…). An object that matches a TOCP entry shows its designation.
  • A TNS type (SN Ia, Nova, AGN, …) decides an object's class whoever saw it; without one, the broker's label does.
  • An object is active while it has detections in the window. A TNS or CBAT object ATLAS does not measure (fainter than 19, older than two months, or not yet measured) is active only while the window holds its last report, so it leaves the short windows a week later.

Pages

  • Dashboard: how many alerts and objects arrived in a window, what kinds, where on the sky, and the brightest new supernova candidates.
  • Sky: the map. Most of what follows is about it.
  • Objects: the same objects as a table you can sort, filter by the broker's label or TNS type, and page through; click one for its light curve and images.
  • Tonight: a planner for your telescope. Pick your site and telescope, and it lists the supernovae, novae and new objects seen this week that are above your horizon while it is dark and bright enough to see, sorted by when each is best placed, with finder charts, a CSV export and a printable list.

Search

  • An object id (ZTF26abvkmbu, a Rubin id, or the first few characters), a TNS name (SN 2026abc), coordinates (35.71 -4.75 or 02:22:50 -04:45:00, add r=10' for a radius), a deep-drilling field (COSMOS), a class (SN Ia, EclBin) or any name astronomers use (M31).

On the map: zoom to go deeper

  • Whole sky (wider than 20°): a heatmap of how many objects were seen in each patch of sky.
  • Region (1°–20°): a finer heatmap plus numbered badges. The number is the count of objects, the color is their most common class, and a white ring means something new in the last night.
  • Objects (under 1°): one dot per object. A white ring means it was seen last night, and a white center means it has been detected only once so far. Click a dot for its light curve, classification and images.

Drag to pan, scroll or pinch to zoom, or click a badge to zoom into it.

Filters

  • Window: how far back to look, from last night to a year.
  • Active / new: objects detected in the window, or only those first seen in it.
  • Class: most alerts are solar-system objects (asteroids). Pick Non-Solar System to hide them and see what else is out there.
  • Brightness (≤ 20, ≤ 18, ≤ 16): only objects at least that bright. Smaller magnitudes are brighter. An object marked faded was last seen fainter than in the survey's reference image, so it has no brightness of its own and counts only under any mag.
  • History (2+ nights, …): only objects seen on several nights, which filters out one-off artifacts.

Observing from your site

  • Your site: an observatory from the list, or your latitude and longitude (typed, or Use my location). A position is rounded to half a degree, and the site is remembered in this browser only.
  • Object panel: when the object is up tonight, its altitude through the night with the moon, the next 60 nights, and a Finder chart with a link to AAVSO's comparison stars.
  • Objects: Visible from… keeps what is above your limit in tonight's dark window, with when and how high.
  • Sky: Observer… shades what is below your horizon at a time you pick; the counts do not change.
  • Tonight: Subscribe gives an RSS feed of your setup, one item a night with the picks, once the data through the night before are in (or three hours before dark). A condition (novae, rare types, something brighter than a magnitude) leaves nights without a match out, so a feed-to-email service mails only those. The plan is also JSON, for scripts and robotic telescopes. A feed's address holds your rounded site and setup: a reader or email service you give it to keeps it.
  • Where your data count: the surveys measure their own objects every few nights, but a TNS or CBAT object gets only ATLAS's photometry, and only while it is brighter than 19. Unconfirmed marks one reported on a single night in the last two weeks: a detection confirms it, and a deep non-detection is news too. No recent data marks one seen on two or more nights that nothing has measured for four nights or more: a magnitude fills the gap in its light curve.

Dark means the sun more than 12° below the horizon (18° if you choose). Positions ignore refraction and precession, a few tenths of a degree: enough to plan, not to point.

Classes

  • SN candidate
  • AGN / nuclear
  • Variable star
  • Solar system
  • Cataloged
  • Unknown
  • Low reliability
  • Other

Data credits

Fink: ZTF and Rubin alerts: classifications, light curves and cutouts
Möller et al. 2021, MNRAS 501, 3272; ZTF (Bellm et al. 2019) and the Vera C. Rubin Observatory LSST.
Transient Name Server (TNS): names, types and discovery reports of transients from every survey
The IAU Transient Name Server, operated by the Weizmann Institute of Science; reports by the surveys named on each object.
CBAT: the Transient Object Confirmation Page: bright novae and other transients reported to the Central Bureau
Central Bureau for Astronomical Telegrams, Transient Object Confirmation Page (TOCP).
ATLAS: forced photometry of TNS objects, from the ATLAS forced-photometry server
Tonry et al. 2018, PASP 130, 064505; Smith et al. 2020, PASP 132, 085002; Shingles et al. 2021, TNS AstroNote 2021-7.
CDS, Strasbourg: sky imagery (HiPS), finder charts (hips2fits) and name resolution (Sesame)
This research has made use of the CDS services, Strasbourg Astronomical Observatory, France.

Everything here is also JSON: Data and API has the public API, the feeds, the exports and how to cite the data.

The data is refreshed nightly. Every view is a link: on the map the URL records the position, zoom, filters and selected object, so Copy link shares exactly what you see.

Made by jgriz

Objects

Objects
Source
Bucket
Clear
3,551–3,600 of 212,839 · All objects seen in the 7 nights
ObjectClassLast magRisePeakFirst seenLast seenNightsDetectionsRel.RA, DecPartner
ZTF ZTF26abydnun Solar System MPC19.27 r—19.272026-09-302026-09-30111.00332.2856, -16.3278
ZTF ZTF26abydnuo Solar System MPC19.26 r—19.262026-09-302026-09-30111.00331.8068, -16.7452
ZTF ZTF26abydnup Solar System MPC19.44 r—19.442026-09-302026-09-30111.00332.0841, -16.1470
ZTF ZTF26abydnvc Solar System MPC14.65 r—14.652026-09-302026-09-30111.00332.5649, -15.6468
ZTF ZTF26abydnvd Solar System MPC18.61 r—18.612026-09-302026-09-30111.00332.4273, -15.8101
ZTF ZTF26abydnve Solar System MPC18.58 r—18.582026-09-302026-09-30111.00332.7845, -15.7267
ZTF ZTF26abydnvg Solar System MPC19.05 r—19.052026-09-302026-09-30111.00332.9274, -15.5822
ZTF ZTF26abydnvh Solar System MPC19.36 r—19.362026-09-302026-09-30110.99333.1533, -15.9400
ZTF ZTF26abydnvq Solar System MPC16.56 r—16.562026-09-302026-09-30111.00334.1121, -19.2504
ZTF ZTF26abydnvr Solar System MPC18.81 r—18.812026-09-302026-09-30111.00333.5738, -19.4977
ZTF ZTF26abydnvt Solar System MPC19.51 r—19.512026-09-302026-09-30111.00333.4473, -19.6928
ZTF ZTF26abydnvv Solar System MPC19.14 r+3.719.142026-09-302026-09-30111.00333.4808, -19.8190
ZTF ZTF26abydnxb Solar System MPC19.63 r—19.632026-09-302026-09-30110.99335.8291, -19.3343
ZTF ZTF26abydnyx Solar System MPC17.96 r—17.962026-09-302026-09-30111.00333.7234, -19.9645
ZTF ZTF26abydnyy Solar System MPC18.48 r—18.482026-09-302026-09-30111.00334.0810, -20.1908
ZTF ZTF26abydnyz Solar System MPC18.24 r—18.242026-09-302026-09-30111.00333.5501, -20.7352
ZTF ZTF26abydnza Solar System MPC18.41 r—18.412026-09-302026-09-30111.00334.0080, -20.4320
ZTF ZTF26abydnzb Solar System MPC18.63 r—18.632026-09-302026-09-30111.00333.9678, -20.0760
ZTF ZTF26abydnzc Solar System MPC18.51 r—18.512026-09-302026-09-30111.00333.6629, -20.5244
ZTF ZTF26abydoaj Solar System MPC18.37 r—18.372026-09-302026-09-30111.00331.9927, -15.4017
ZTF ZTF26abydoal Solar System MPC18.94 r—18.942026-09-302026-09-30111.00331.7081, -15.7838
ZTF ZTF26abydoam Solar System MPC18.87 r—18.872026-09-302026-09-30111.00331.5846, -16.0425
ZTF ZTF26abydoan Solar System MPC19.09 r—19.092026-09-302026-09-30110.99331.8521, -15.8956
ZTF ZTF26abydoao Solar System MPC19.43 r—19.432026-09-302026-09-30111.00331.4891, -15.3333
ZTF ZTF26abydoap Solar System MPC19.28 r—19.282026-09-302026-09-30111.00332.0093, -15.9985
ZTF ZTF26abydoaq Solar System MPC19.43 r—19.432026-09-302026-09-30111.00331.9176, -15.7436
ZTF ZTF26abydoar Solar System MPC18.53 r—18.532026-09-302026-09-30111.00334.6210, -19.5676
ZTF ZTF26abydoas Solar System MPC18.97 r—18.972026-09-302026-09-30111.00335.0959, -19.1869
ZTF ZTF26abydocf Solar System MPC17.00 r—17.002026-09-302026-09-30111.00335.8850, -20.1644
ZTF ZTF26abydocg Solar System MPC17.92 r+2.917.922026-09-302026-09-30111.00335.4898, -20.2390
ZTF ZTF26abydoch Solar System MPC18.16 r—18.162026-09-302026-09-30111.00335.7051, -20.3702
ZTF ZTF26abydoci Solar System MPC19.38 r—19.382026-09-302026-09-30111.00335.7132, -20.5194
ZTF ZTF26abydodq Solar System MPC16.43 r—16.432026-09-302026-09-30111.00330.7957, -16.0235
ZTF ZTF26abydodr Solar System MPC18.15 r—18.152026-09-302026-09-30111.00330.9069, -15.7022
ZTF ZTF26abydods Solar System MPC19.05 r—19.052026-09-302026-09-30111.00330.7824, -15.9776
ZTF ZTF26abydodx Solar System MPC17.43 r—17.432026-09-302026-09-30111.00329.6832, -15.4306
ZTF ZTF26abydody Solar System MPC17.53 r—17.532026-09-302026-09-30111.00330.2658, -15.6947
ZTF ZTF26abydodz Solar System MPC17.58 r—17.582024-11-222026-09-30111.00329.5406, -15.9141
ZTF ZTF26abydoea Solar System MPC18.21 r—18.212018-07-222026-09-30111.00329.7617, -15.6775
ZTF ZTF26abydoeb Solar System MPC18.52 r—18.522026-09-302026-09-30111.00329.9003, -15.5004
ZTF ZTF26abydogo Solar System MPC15.18 r—15.182026-09-302026-09-30111.00332.4612, -20.0179
ZTF ZTF26abydogq Solar System MPC19.18 r—19.182026-09-302026-09-30111.00332.4797, -19.9603
ZTF ZTF26abydogr Solar System MPC19.15 r—19.152026-09-302026-09-30111.00332.9371, -19.9443
ZTF ZTF26abydogx Solar System MPC14.69 r—14.692023-11-132026-09-30111.00329.9061, -16.8605
ZTF ZTF26abydogy Solar System MPC17.24 r—17.242026-09-302026-09-30111.00330.0752, -16.6811
ZTF ZTF26abydogz Solar System MPC17.89 r+4.517.892026-09-302026-09-30111.00329.7226, -16.4171
ZTF ZTF26abydoha Solar System MPC18.05 r—18.052026-09-302026-09-30111.00330.0694, -16.1340
ZTF ZTF26abydohb Solar System MPC18.44 r—18.442026-09-302026-09-30111.00329.9390, -16.2454
ZTF ZTF26abydojw Solar System MPC17.54 r—17.542026-09-302026-09-30111.00330.2972, -20.6740
ZTF ZTF26abydokk Solar System MPC15.86 r—15.862026-09-302026-09-30111.00331.2677, -14.6857