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.

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.

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
2,151–2,200 of 214,516 · All objects seen in the 7 nights
ObjectClassLast magRisePeakFirst seenLast seenNightsDetectionsRel.RA, DecPartner
ZTF ZTF18acegehb CataclyV*AT 2020kse18.35 r+1.618.132018-02-112026-09-2916161.00132.8061, 34.7467
ZTF ZTF18acidpfv Unknown16.21 r+0.116.212017-11-212026-09-29110.78132.5596, 35.9604
ZTF ZTF18acvhhoy Unknownfaded r−0.219.232018-12-122026-09-2920231.00131.4679, 35.0719
ZTF ZTF19aaicyac Unknownfaded r−0.2—2018-11-182026-09-29561.00131.5678, 33.8303
ZTF ZTF19aarsunp BLLac18.98 r+0.218.322019-02-082026-09-2934551.00132.6510, 34.9232
ZTF ZTF19acjhvmx Unknownfaded r−0.217.232017-10-282026-09-2933481.00130.5281, 36.2117
ZTF ZTF20aakxrzn BYDraV*faded r−0.118.082018-09-192026-09-2925281.00129.5813, 34.7727
ZTF ZTF20aapywfg QSOfaded r−0.419.352019-02-082026-09-2930481.00130.7885, 36.6940
ZTF ZTF21aakzvad QSO19.34 r+0.519.042019-12-292026-09-29731151.00129.9067, 35.0557
ZTF ZTF21acckjyb EclBinfaded r−0.2—2017-11-192026-09-29221.00132.5179, 32.2054
ZTF ZTF22abmojjg Unknownfaded r−0.1—2017-11-192026-09-29110.94137.5775, 32.2094
ZTF ZTF23aaavkrr PulsV*faded r−0.3—2017-11-212026-09-29331.00132.0366, 36.1064
ZTF ZTF23aaclpjs Unknown19.10 r+1.119.102022-12-172026-09-2928401.00136.8917, 32.4326
ZTF ZTF25aawucwu Unknownfaded r−0.217.372018-11-132026-09-2944711.00130.3807, 33.7191
ZTF ZTF26abvzwcd SN candidateAT 2026acrm19.60 r—19.552026-09-182026-09-29221.00132.6184, 36.4583
ZTF ZTF26abyamig Solar System MPC19.12 r—19.122026-09-292026-09-29111.00136.3949, 29.6386
ZTF ZTF26abyamky Solar System MPC19.42 r—19.422026-09-292026-09-29111.00131.5203, 34.7873
ZTF ZTF26abyamla Solar System MPC18.09 r—18.092026-09-292026-09-29111.00136.9618, 30.7911
ZTF ZTF26abyamoa Solar System MPC18.58 r—18.582026-09-292026-09-29111.00132.4885, 29.7650
ZTF ZTF26abyamoi Solar System MPC18.65 r—18.652026-09-292026-09-29111.00131.4944, 31.7911
ZTF ZTF26abyamoj Solar System MPC18.29 r—18.292026-09-292026-09-29111.00130.7988, 30.5377
ZTF ZTF26abyamok Solar System MPC19.21 r—19.212026-09-292026-09-29110.99130.8404, 30.5488
ZTF ZTF26abyampu Solar System MPC19.45 r—19.452026-09-292026-09-29111.00136.5583, 32.7233
ZTF ZTF26abyamqi Solar System candidate19.03 r+3.819.032026-09-292026-09-29110.00132.3846, 34.2615
ZTF ZTF26abyamqp Solar System MPC19.43 r—19.432026-09-292026-09-29111.00131.5371, 29.6891
ZTF ZTF26abyamqz Solar System MPC18.68 r—18.682026-09-292026-09-29111.00130.0660, 34.6539
ZTF ZTF26abyamrn Unknown18.67 r+1.718.672026-09-292026-09-29111.00130.8531, 34.0199
ZTF ZTF26abyamtn Solar System MPC19.16 r—19.162026-09-292026-09-29111.00131.7007, 35.5305
ZTF ZTF26abyamuq Solar System MPC19.29 r—19.292026-09-292026-09-29111.00130.3172, 32.6676
ZTF ZTF26abyamus Solar System MPC19.53 r—19.532026-09-292026-09-29110.99130.4698, 32.8402
ZTF ZTF26abyamwz Solar System MPC18.44 r+4.618.442026-09-292026-09-29111.00131.6823, 32.5769
ZTF ZTF26abyamzb Solar System MPC17.01 r—17.012026-09-292026-09-29111.00129.5542, 30.9483
ZTF ZTF26abyanfe Solar System MPC19.22 r—19.222026-09-292026-09-29111.00133.9690, 30.5262
ZTF ZTF26abyanhd Solar System MPC19.35 r—19.352026-09-292026-09-29110.99132.0218, 30.8544
ZTF ZTF26abyanhe Solar System MPC19.42 r—19.422026-09-292026-09-29111.00131.4800, 30.5532
ZTF ZTF26abyanig Solar System MPC19.45 r—19.452026-09-292026-09-29111.00133.2511, 30.7362
ZTF ZTF26abyanmg Solar System MPC17.68 r—17.682026-09-292026-09-29111.00129.9593, 30.0948
ZTF ZTF26abyanmi Solar System MPC18.56 r—18.562026-09-292026-09-29111.00130.1035, 30.2015
ZTF ZTF26abyanmj Solar System MPC18.62 r—18.622026-09-292026-09-29111.00129.8095, 29.9729
ZTF ZTF26abyanmk Solar System MPC18.88 r—18.882026-09-292026-09-29111.00130.0170, 29.6386
ZTF ZTF26abyanml Solar System MPC18.75 r—18.752026-09-292026-09-29111.00129.9854, 30.0443
ZTF ZTF26abyanmm Solar System candidate19.39 r—19.392026-09-292026-09-29111.00129.4700, 30.1548
ZTF ZTF26abyanmn Solar System candidate19.64 r—19.642026-09-292026-09-29111.00129.4462, 30.2384
ZTF ZTF17aaagvsz CataclyV*faded r−1.513.112017-12-082026-09-2952791.00127.1538, 25.3342
ZTF ZTF17aaagvta EclBin18.36 r+0.217.632017-12-142026-09-2937481.00126.8997, 24.9358
ZTF ZTF17aaagwoc EclBinfaded r−0.218.262017-12-142026-09-2934411.00129.5982, 22.7493
ZTF ZTF17aaaivav QSOfaded r−1.218.402017-12-142026-09-29651241.00126.1375, 24.6452
ZTF ZTF17aaaivca RRLyraefaded r−0.216.102017-12-082026-09-2965961.00124.5505, 29.2376
ZTF ZTF17aaaivch RRLyrae16.69 r+0.316.152017-12-082026-09-2943551.00129.0463, 25.5700
ZTF ZTF17aaaizir RRLyrae17.24 r+0.317.162017-12-082026-09-2944581.00128.5142, 25.7220