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
2,501–2,550 of 214,524 · All objects seen in the 7 nights
ObjectClassLast magRisePeakFirst seenLast seenNightsDetectionsRel.RA, DecPartner
ZTF ZTF18acwwloy QSO18.89 r+0.418.662018-11-072026-09-2951921.00122.2935, 2.9303
ZTF ZTF18acwwlrr Unknown18.62 r+0.118.602018-12-162026-09-2926321.00125.9182, 2.2030
ZTF ZTF18acwwlvr Unknown16.60 r+0.116.602018-11-072026-09-29661.00120.8935, 1.8807
ZTF ZTF18acwwlwy HotSubdwarf_Candidate17.75 r+0.316.892018-01-112026-09-29871611.00122.3713, 5.0572
ZTF ZTF18acwwlxc EclBin19.19 r+0.218.962018-01-132026-09-2938431.00122.4277, 5.0125
ZTF ZTF18acwwlxk Unknownfaded r−0.118.282018-11-072026-09-29451.00121.1365, 2.0694
ZTF ZTF18acwxmwp Unknown17.18 r+0.117.182018-11-172026-09-29110.83124.0803, 3.7876
ZTF ZTF18acwxngf EclBinfaded r−0.518.692017-12-152026-09-2913141.00122.3246, 2.1207
ZTF ZTF18aczconz Unknown17.14 r+0.116.422018-11-172026-09-2932461.00121.6315, 7.6510
ZTF ZTF18aczcorl Starfaded r−0.1—2018-12-202026-09-29221.00122.4562, 7.8900
ZTF ZTF18aczcpbq Variable*16.15 r+0.115.972018-04-022026-09-2921261.00122.1661, 4.6948
ZTF ZTF18aczcpjq EclBin19.06 r+0.117.662017-12-142026-09-2947661.00123.3980, 5.6972
ZTF ZTF18aczehco EclBin18.07 r+0.218.072017-12-142026-09-2940521.00122.6896, 7.7775
ZTF ZTF18aczehdq EclBinfaded r−0.216.852018-01-142026-09-2933421.00120.8725, 3.1210
ZTF ZTF18aczehlj Unknownfaded r−0.217.822018-12-202026-09-2949601.00124.1187, 1.8866
ZTF ZTF18aczehpa Unknownfaded r−0.1—2018-12-202026-09-29771.00123.1848, 1.9752
ZTF ZTF18adaykck Unknownfaded r−0.116.812018-04-022026-09-2952731.00124.7075, 1.6528
ZTF ZTF18adaykqj Unknownfaded r−0.1—2018-12-282026-09-2915170.99120.8904, 2.1840
ZTF ZTF18adayksg Unknownfaded r−0.1—2018-12-282026-09-2939481.00126.3604, 1.2493
ZTF ZTF18adbgzok EclBinfaded r−0.215.452018-04-022026-09-296101.00124.9467, 2.5291
ZTF ZTF18adbgzol Unknown18.48 r+0.118.482018-12-292026-09-29661.00124.9768, 2.0123
ZTF ZTF18adbnusq EclBinfaded r−0.318.022017-12-142026-09-2925311.00120.1973, 7.7284
ZTF ZTF18adbybtl EclBinfaded r−0.1—2018-11-172026-09-29331.00120.2887, 6.1380
ZTF ZTF18adfhkmh Unknown19.08 r+0.219.082018-11-172026-09-2931361.00124.9675, 3.2200
ZTF ZTF18adowndd Unknownfaded r−0.1—2018-01-112026-09-29110.97126.7598, 2.2211
ZTF ZTF18adqvcxh Unknown14.87 r+0.214.872018-12-302026-09-2941611.00120.2464, 2.9437
ZTF ZTF19aaaoijv Unknownfaded r−0.1—2018-12-202026-09-2928281.00123.5464, 1.1766
ZTF ZTF19aaaokcn Unknownfaded r−0.118.242018-12-132026-09-2945621.00125.0187, 3.8213
ZTF ZTF19aaaokdj Starfaded r−0.118.552018-04-022026-09-29551.00123.0405, 7.5457
ZTF ZTF19aaaokrz Unknown17.38 r+0.016.902019-01-042026-09-29661.00122.0693, 4.1206
ZTF ZTF19aaaorsv Star16.68 r+0.216.682018-04-022026-09-29721001.00123.5934, 7.1820
ZTF ZTF19aaaosgc Unknown18.45 r+0.218.252019-01-042026-09-2954871.00122.8360, 1.5991
ZTF ZTF19aaaosjx Unknownfaded r−0.215.842018-04-022026-09-29621091.00122.7864, 3.7215
ZTF ZTF19aaaosld Unknown18.05 r+0.218.052018-12-292026-09-2943631.00127.2923, 2.3547
ZTF ZTF19aaaospu Unknownfaded r−0.1—2019-01-042026-09-2915231.00120.6451, 3.4575
ZTF ZTF19aabvzsf Unknownfaded r−0.115.172018-12-292026-09-297181.00122.1295, 4.0892
ZTF ZTF19aabwbne Unknown18.31 r+0.118.182018-11-172026-09-2931391.00124.1483, 2.7850
ZTF ZTF19aabwwpn Unknownfaded r−0.118.252019-01-082026-09-2940591.00122.2394, 1.7841
ZTF ZTF19aadlzxv Unknown18.38 r+0.217.802019-01-122026-09-2942721.00121.3796, 7.1083
ZTF ZTF19aadmaot LongPeriodV*faded r−0.1—2018-11-072026-09-29551.00120.7432, 1.0817
ZTF ZTF19aaeqdpr Unknownfaded r−0.214.982018-04-022026-09-2955991.00124.9850, 3.2003
ZTF ZTF19aaiqmgp UnknownAT 2018bdkfaded r−1.318.872018-12-132026-09-29661011.00126.1354, 3.6422
ZTF ZTF19aajyqbh Unknown18.11 r+0.117.762019-02-122026-09-29661.00124.4938, 3.5268
ZTF ZTF19aakilkg Unknownfaded r−0.1—2019-02-122026-09-29330.32125.7811, 2.9214
ZTF ZTF19aalxzzv Unknown18.58 r+0.118.582018-01-112026-09-29221.00122.3964, 1.0713
ZTF ZTF19aamkddr EclBinfaded r−0.318.042019-03-152026-09-29671.00121.4091, 2.3636
ZTF ZTF19aamucrw Unknownfaded r−0.115.292018-01-142026-09-297111.00120.3224, 5.5098
ZTF ZTF19aannxvz Unknown18.49 r+0.218.492018-11-052026-09-29701121.00121.5129, 6.0939
ZTF ZTF19aannxyb QSO19.08 r+0.818.982018-11-082026-09-29731251.00122.1556, 5.4808
ZTF ZTF19aapcnug Unknownfaded r−0.117.092019-02-092026-09-29781.00124.4209, 3.6330