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
2,901–2,950 of 214,524 · All objects seen in the 7 nights
ObjectClassLast magRisePeakFirst seenLast seenNightsDetectionsRel.RA, DecPartner
ZTF ZTF19acifssa Unknown17.40 r+0.117.402018-11-172026-09-29661.00124.4867, -4.8503
ZTF ZTF19acifstn Unknownfaded r−0.1—2019-04-262026-09-2910101.00119.1551, -0.1643
ZTF ZTF19aciftaz Variable*faded r−0.1—2019-01-042026-09-29991.00118.3081, -2.7808
ZTF ZTF19aclhnro Starfaded r−0.1—2019-10-312026-09-2954921.00121.0001, -4.0728
ZTF ZTF19aclhntp Unknownfaded r−0.116.852019-10-192026-09-2968911.00120.3827, -2.2482
ZTF ZTF19acpkzmj Unknownfaded r−0.1—2019-11-062026-09-2924271.00118.8868, -5.0911
ZTF ZTF19acvrffb Unknownfaded r−0.1—2019-11-252026-09-2952681.00122.0770, -5.7471
ZTF ZTF19acvrgsh Star17.50 r+0.217.502018-11-072026-09-2916191.00121.9550, -3.1943
ZTF ZTF19acxnode Unknownfaded r−0.1—2019-10-192026-09-2927331.00120.2023, -3.2560
ZTF ZTF19acxnscv EclBinfaded r−0.2—2018-11-072026-09-29551.00119.7268, -6.0137
ZTF ZTF19acxnzsv delSctV*16.95 r+0.216.852018-11-072026-09-2925261.00119.7996, 0.5272
ZTF ZTF19acxobav Unknownfaded r−0.1—2019-02-262026-09-2943551.00119.7636, -3.9567
ZTF ZTF19acxodtp Unknownfaded r−0.117.642019-12-102026-09-29761151.00119.8834, -0.1256
ZTF ZTF19acxwkwa Starfaded r−0.1—2018-11-202026-09-2910101.00120.3796, -6.3409
ZTF ZTF19acxxgnz AGNfaded r−0.519.422019-03-192026-09-29661021.00120.1373, -0.3604
ZTF ZTF19acxxkmq AGNfaded r−0.818.672019-10-192026-09-29861481.00120.2470, -0.0670
ZTF ZTF19acxyare AGN19.03 r+0.318.472019-03-252026-09-29771271.00121.1646, -0.9850
ZTF ZTF19aczjarc EclBin19.00 r+0.118.242018-11-072026-09-2928291.00119.0884, -0.1492
ZTF ZTF19adblmaj Unknown17.46 r+0.217.462018-12-292026-09-29551.00122.0369, -5.4525
ZTF ZTF19adlfhcp Unknown18.19 r+0.118.192018-11-192026-09-29111.00120.3955, -2.4608
ZTF ZTF20aabfygx Unknown17.98 r+0.217.782019-10-252026-09-2945741.00120.1653, -3.6972
ZTF ZTF20aabhgyh Unknownfaded r−0.1—2019-10-042026-09-2914151.00120.3515, -4.4114
ZTF ZTF20aabivca Unknown18.80 r+0.118.802020-01-022026-09-29221.00118.1149, -4.3169
ZTF ZTF20aabivuf Unknownfaded r−0.2—2020-01-022026-09-2947611.00118.6457, -1.8163
ZTF ZTF20aabiwmr Unknownfaded r−0.118.712020-01-022026-09-2917171.00118.2773, -2.2042
ZTF ZTF20aabjejx Unknown19.09 r+0.319.092020-01-022026-09-2928301.00118.7787, -1.9773
ZTF ZTF20aabjtha Star19.06 r+0.118.902020-01-022026-09-2921341.00124.8276, -4.8910
ZTF ZTF20aabkixs Unknownfaded r−0.1—2019-10-082026-09-2933471.00119.7310, -5.8439
ZTF ZTF20aabkpri Unknownfaded r−0.1—2018-11-072026-09-2940521.00118.7512, 0.6684
ZTF ZTF20aabkqht EclBin17.79 r+0.117.402018-11-072026-09-2922271.00118.4849, -2.8487
ZTF ZTF20aablcxb RRLyraefaded r−0.215.242018-11-072026-09-2918191.00122.6766, -5.1444
ZTF ZTF20aablgca Unknown18.63 r+0.118.262018-11-172026-09-29330.91119.3988, -3.6298
ZTF ZTF20aablony EclBin18.73 r+0.317.872017-12-082026-09-2951661.00119.3100, 0.1987
ZTF ZTF20aabmdce EclBin18.21 r+0.218.182018-11-102026-09-29551.00123.6884, -5.0293
ZTF ZTF20aabngsm RRLyrae18.94 r+0.118.602017-12-082026-09-29221.00119.1705, -0.8360
ZTF ZTF20aacouqy QSOfaded r−0.6—2020-01-042026-09-2945761.00118.7478, -4.3219
ZTF ZTF20aacrkmq Unknown17.57 r+0.117.572018-11-172026-09-29111.00117.9482, -5.3559
ZTF ZTF20aactloc Unknownfaded r−0.1—2018-11-072026-09-29550.99119.6486, -1.1569
ZTF ZTF20aaedwbr EclBin17.31 r+0.117.312017-12-082026-09-29221.00120.3923, -3.1300
ZTF ZTF20aaefagv Starfaded r−0.1—2020-01-022026-09-2917201.00121.5961, -3.3814
ZTF ZTF20aaefptn EclBinfaded r−0.1—2018-11-072026-09-29111.00120.9964, -1.8000
ZTF ZTF20aafzeut Unknown18.25 r+0.218.252020-01-022026-09-29701041.00123.8220, -5.5605
ZTF ZTF20aalmujd Unknown18.92 r+0.318.922020-01-042026-09-29661.00121.2162, 0.1716
ZTF ZTF20aanohqh Unknownfaded r−0.2—2019-03-162026-09-2925271.00123.7765, -3.6027
ZTF ZTF20aaohkpf Unknown18.34 r+0.118.342018-11-172026-09-29670.87122.4972, -4.3549
ZTF ZTF20aaotncr Unknown18.82 r+0.218.792020-01-272026-09-2930461.00119.8152, -5.4956
ZTF ZTF20aarcfgv Unknownfaded r——2020-01-022026-09-29561.00123.8194, -3.6151
ZTF ZTF20aavfepw Unknown18.04 r+0.118.042018-12-032026-09-29551.00118.7066, -2.7669
ZTF ZTF20acitzuj AGNfaded r−0.418.922020-01-272026-09-29781291.00118.7676, 0.3987
ZTF ZTF20aciubtf Unknown17.47 r+0.217.472018-12-202026-09-2950821.00119.0526, -3.6177