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
3,101–3,150 of 214,524 · All objects seen in the 7 nights
ObjectClassLast magRisePeakFirst seenLast seenNightsDetectionsRel.RA, DecPartner
ZTF ZTF19acysftz Unknownfaded r−0.117.152017-12-242026-09-2916160.98120.1311, 21.7694
ZTF ZTF20aabmwlc EclBinfaded r−0.2—2018-01-132026-09-2916171.00125.5969, 17.2372
ZTF ZTF20aaedfca Variable*19.04 r+0.119.042018-11-022026-09-29110.99123.6507, 15.2425
ZTF ZTF20aaedqlp Unknown15.19 r+0.115.192018-11-032026-09-29110.13121.8551, 17.2859
ZTF ZTF21aaciyuy QSO19.01 r+0.718.702019-11-042026-09-29811501.00124.5934, 17.7576
ZTF ZTF21abxzcno Seyfert119.28 r+0.819.282019-03-272026-09-29661.00121.0574, 20.6983
ZTF ZTF24aabsbtl Unknown18.12 r+0.217.992019-01-282026-09-2945551.00122.2709, 15.2885
ZTF ZTF24aadcnxq Unknownfaded r−0.118.822018-11-062026-09-2921241.00124.8548, 17.8288
ZTF ZTF25aacylkx Unknown19.17 r+0.119.172019-02-262026-09-29111.00120.7588, 16.6695
ZTF ZTF25abpsryn Solar System MPC16.39 r—16.392025-09-092026-09-29221.00121.1330, 19.7759
ZTF ZTF25abztmbz Unknown18.12 r+0.118.122018-09-112026-09-29771.00124.1711, 15.4876
ZTF ZTF25ackwuvs Unknownfaded r−0.1—2017-12-142026-09-29110.88120.8813, 16.5025
ZTF ZTF26abyamts Solar System MPC14.11 r—14.112026-09-292026-09-29111.00126.5873, 16.7698
ZTF ZTF26abyamtt Solar System MPC17.32 r—17.322026-09-292026-09-29111.00126.5521, 16.7455
ZTF ZTF26abyamtu Solar System MPC17.45 r—17.452026-09-292026-09-29111.00126.3927, 16.4980
ZTF ZTF26abyamtv Solar System MPC18.24 r—18.242026-09-292026-09-29111.00126.6068, 16.5592
ZTF ZTF26abyamtw Solar System MPC18.68 r—18.682026-09-292026-09-29111.00125.9476, 16.2070
ZTF ZTF26abyamty Solar System MPC19.30 r—19.302026-09-292026-09-29110.99126.6421, 16.3365
ZTF ZTF26abyamwt Solar System MPC17.85 r—17.852026-09-292026-09-29111.00122.2371, 16.3301
ZTF ZTF26abyamyw Solar System MPC17.79 r—17.792026-09-292026-09-29111.00123.1594, 19.6661
ZTF ZTF26abyanbp Solar System MPC16.63 r—16.632026-09-292026-09-29111.00123.2536, 16.1314
ZTF ZTF26abyanci Solar System MPC17.67 r—17.672026-09-292026-09-29111.00123.3231, 21.9176
ZTF ZTF26abyancv Solar System MPC19.05 r—19.052026-09-292026-09-29110.99126.6931, 18.1158
ZTF ZTF26abyandy Solar System MPC18.14 r—18.142026-09-292026-09-29111.00125.2979, 15.5275
ZTF ZTF26abyanea Solar System MPC18.93 r—18.932026-09-292026-09-29111.00125.7438, 15.8439
ZTF ZTF26abyanfl Solar System MPC18.86 r—18.862020-04-152026-09-29110.99123.4422, 17.4865
ZTF ZTF26abyanft Solar System MPC16.58 r—16.582026-09-292026-09-29111.00121.6334, 17.5848
ZTF ZTF26abyangb Solar System MPC18.92 r—18.922026-09-292026-09-29111.00124.7251, 18.7277
ZTF ZTF26abyangh Solar System MPC18.83 r—18.832026-09-292026-09-29111.00122.2161, 19.5672
ZTF ZTF26abyangj Solar System MPC19.26 r—19.262026-09-292026-09-29111.00122.2761, 19.5762
ZTF ZTF26abyangl Solar System MPC19.20 r—19.202026-09-292026-09-29111.00122.4570, 19.7335
ZTF ZTF26abyangv Solar System MPC17.03 r—17.032026-09-292026-09-29111.00121.2722, 18.6087
ZTF ZTF26abyangw Solar System MPC18.50 r—18.502026-09-292026-09-29111.00121.5406, 18.4954
ZTF ZTF26abyangx Solar System MPC18.53 r—18.532026-09-292026-09-29111.00121.0359, 18.1511
ZTF ZTF26abyanhs Solar System MPC17.16 r—17.162026-09-292026-09-29111.00122.4726, 17.8261
ZTF ZTF26abyanht Solar System MPC18.00 r—18.002026-09-292026-09-29111.00122.5105, 17.8450
ZTF ZTF26abyanhu Unknown18.62 r—18.622026-09-292026-09-29111.00122.2313, 17.5058
ZTF ZTF26abyaniy Solar System MPC16.73 r—16.732026-09-292026-09-29111.00125.3145, 18.3204
ZTF ZTF26abyanjb Solar System MPC18.24 r—18.242026-09-292026-09-29111.00124.9076, 18.4301
ZTF ZTF26abyanjc Solar System MPC18.58 r—18.582026-09-292026-09-29111.00125.6549, 18.7043
ZTF ZTF26abyanje Solar System MPC19.10 r—19.102026-09-292026-09-29111.00125.0251, 18.5049
ZTF ZTF26abyanjr Solar System MPC18.09 r—18.092026-09-292026-09-29111.00121.5651, 15.5494
ZTF ZTF26abyankb Solar System MPC18.82 r—18.822026-09-292026-09-29111.00120.5055, 18.7707
ZTF ZTF26abyankd Solar System MPC18.78 r—18.782026-09-292026-09-29111.00120.5273, 15.2220
ZTF ZTF26abyanke Solar System MPC19.01 r—19.012026-09-292026-09-29111.00120.6162, 15.3729
ZTF ZTF26abyankf Solar System MPC18.96 r+1.918.962026-09-292026-09-29110.98120.6102, 15.8892
ZTF ZTF26abyankm Solar System MPC16.81 r—16.812026-09-292026-09-29111.00122.8762, 15.4665
ZTF ZTF26abyankn Solar System MPC18.39 r—18.392026-09-292026-09-29111.00122.2755, 15.5502
ZTF ZTF26abyankp Solar System MPC19.01 r—19.012026-09-292026-09-29111.00122.8113, 15.7098
ZTF ZTF26abyankq Solar System MPC19.26 r—19.262026-09-292026-09-29111.00122.5768, 15.8877