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
2,001–2,050 of 256,284 · All objects seen in the 7 nights
ObjectClassLast magRisePeakFirst seenLast seenNightsDetectionsRel.RA, DecPartner
ZTF ZTF18acrxnku Unknownfaded r−0.117.062018-11-072026-09-2659831.00119.9266, -2.1256
ZTF ZTF18acrxogc Unknownfaded r−0.217.662018-11-282026-09-26651121.00123.5548, 0.4733
ZTF ZTF18acsoskw EclBin17.88 r+0.317.652018-11-072026-09-26771101.00120.1374, -2.3293
ZTF ZTF18acsotcl Variable*faded r−0.117.872018-12-032026-09-26881.00119.4004, -0.3600
ZTF ZTF18acurqai Unknownfaded r−0.2—2018-11-172026-09-26441.00121.2063, 1.6976
ZTF ZTF18acurqak EclBin15.59 r+0.115.382017-12-142026-09-2626321.00121.3420, 1.8823
ZTF ZTF18acvvtzp EclBinfaded r−0.518.432018-01-112026-09-2661871.00119.1809, 3.4802
ZTF ZTF18acvwhmz Unknownfaded r−0.317.912018-11-172026-09-26851541.00120.3246, 0.8140
ZTF ZTF18acvwhop Variable*faded r−0.117.342018-12-132026-09-26461.00121.3961, 2.3836
ZTF ZTF18acvwhor Unknownfaded r−0.315.702018-12-132026-09-26581091.00121.1490, 2.3630
ZTF ZTF18acwwlor EclBinfaded r−0.216.252018-11-072026-09-2613191.00122.2682, 3.3234
ZTF ZTF18acxwsmq Unknownfaded r−0.115.622018-12-172026-09-2645621.00125.0167, -2.7438
ZTF ZTF18adbqeuu Unknown18.68 r+0.318.682018-12-292026-09-26111.00119.7437, 1.8334
ZTF ZTF18adbyhsr EclBinfaded r−0.2—2018-11-172026-09-26331.00119.3709, 3.1394
ZTF ZTF18adpacne Mira12.72 r+2.212.422018-11-102026-09-2664951.00123.9685, -1.8470
ZTF ZTF18adpacnt EclBin19.02 r+0.218.292018-11-102026-09-2635401.00123.4933, -2.4102
ZTF ZTF18adpadqk EclBinfaded r−0.416.782017-12-082026-09-2660871.00123.0049, -1.4610
ZTF ZTF18adpadyt EclBinfaded r−0.617.982018-11-102026-09-2611141.00122.4022, -2.1254
ZTF ZTF18adpfbna Unknownfaded r−0.316.762018-11-172026-09-2653731.00123.2929, -1.6105
ZTF ZTF18adplwwj EclBinfaded r−0.2—2018-11-202026-09-2610101.00124.3584, -2.4117
ZTF ZTF18adqwbub Star17.65 r+0.117.652018-12-292026-09-2631361.00120.0634, 3.8535
ZTF ZTF19aaaokov Unknownfaded r−0.3—2018-01-112026-09-2658911.00119.3383, 1.2667
ZTF ZTF19aabvzsf Unknownfaded r−0.115.172018-12-292026-09-266171.00122.1297, 4.0893
ZTF ZTF19aabwvbg EclBinfaded r−0.218.002018-11-262026-09-2615181.00119.3508, -0.5234
ZTF ZTF19aaerntm EclBinfaded r−0.316.922019-01-262026-09-26691.00122.9169, 0.1608
ZTF ZTF19aafzzdf Unknownfaded r−0.115.722018-11-192026-09-269141.00120.5554, 4.6467
ZTF ZTF19aalcufp Unknownfaded r−0.217.932018-11-072026-09-2650551.00125.2025, -1.5624
ZTF ZTF19aaljcnl Unknownfaded r−0.117.752018-11-192026-09-26671071.00122.7371, -1.3320
ZTF ZTF19aaljeul AGNfaded r−0.518.472018-12-292026-09-26731301.00121.8733, -1.1963
ZTF ZTF19aamrxrp Unknownfaded r−0.218.182018-11-122026-09-2650901.00124.8176, -1.6133
ZTF ZTF19aasaeti Unknownfaded r−0.1—2019-04-262026-09-26331.00122.9249, -1.4634
ZTF ZTF19aasxcbh Unknownfaded r−0.215.262018-11-072026-09-2619201.00122.4915, -2.0180
ZTF ZTF19acbmzez Unknownfaded r−0.215.892018-11-192026-09-2635601.00121.4093, 1.4176
ZTF ZTF19accstlr Starfaded r−0.217.642019-10-012026-09-26721311.00121.7592, -1.7518
ZTF ZTF19acdtkse Unknownfaded r−0.218.702019-10-082026-09-2627391.00120.0884, 0.7451
ZTF ZTF19acnqckr EclBin18.90 r+0.218.232018-11-172026-09-268211.00119.0810, 4.6278
ZTF ZTF19acokzvy Unknownfaded r−0.1—2018-01-112026-09-26771.00121.6327, 1.8309
ZTF ZTF19acpykkv Unknown18.66 r+0.518.632019-02-092026-09-2619241.00121.3014, 1.2527
ZTF ZTF19acxnnqa Unknown18.94 r+0.218.312019-05-052026-09-26631011.00123.7203, 0.6897
ZTF ZTF19acxobmq EclBinfaded r−0.618.612017-12-082026-09-2619191.00122.5378, -1.3109
ZTF ZTF20aabgbbu QSOfaded r−0.3—2019-11-032026-09-2642671.00121.9630, -0.0761
ZTF ZTF20aabgfsl Unknownfaded r−0.118.262020-01-022026-09-2630431.00122.5070, 2.5033
ZTF ZTF20aabjdby Unknownfaded r−0.2—2019-10-082026-09-269111.00122.8734, -1.6371
ZTF ZTF20aagafbr Unknown18.90 r+0.218.622018-11-042026-09-2650611.00119.0430, 3.1927
ZTF ZTF20aaiyftv QSOfaded r−0.418.722020-01-272026-09-267161.00122.2268, 4.4703
ZTF ZTF20aaphqpp Unknownfaded r−0.318.782019-10-272026-09-2661781.00126.2816, -1.2427
ZTF ZTF20aauyoii Unknownfaded r−0.218.852020-04-162026-09-2639511.00122.2168, 2.1276
ZTF ZTF20aaxehlq Unknownfaded r−0.1—2020-04-292026-09-26111.00122.2898, -1.2195
ZTF ZTF20acjivdl Unknown16.99 r+0.116.492018-12-292026-09-265141.00121.8433, -0.6869
ZTF ZTF20acjivdn RRLyrae18.72 r+0.218.272018-11-192026-09-26361.00122.1159, -0.8072