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 discovery, with the reporter's magnitude in its own 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.
  • 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 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.
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
1–50 of 256,032 · All objects seen in the 7 nights
ObjectClassLast magPeakFirst seenLast seenNightsDetectionsRel.RA, DecPartner
ZTF ZTF17aaahimt EclBinfaded r17.472017-12-082026-09-269101.0071.7124, -19.8143
ZTF ZTF17aabrzzd CataclyV*AT 2019coofaded r15.292017-12-082026-09-2622381.0072.2612, -18.6914
ZTF ZTF17aabsagi EclBin16.58 r16.482017-12-082026-09-2631401.0071.7443, -20.6377
ZTF ZTF18acenqto SupernovaSLSN-Ifaded r18.072018-11-062026-09-2624381.0069.7373, -20.6622
ZTF ZTF18aclamab EclBinfaded r14.872017-12-082026-09-2626291.0070.7810, -16.5247
ZTF ZTF18acxhvfb EclBinfaded r16.812017-12-082026-09-2625291.0074.5853, -18.3266
ZTF ZTF19aampqti AGNfaded r17.322018-11-172026-09-2653841.0075.5014, -20.0368
ZTF ZTF20aalbjsa Starfaded r17.252018-11-062026-09-2648821.0075.8905, -19.0744
ZTF ZTF26abxsyoo Solar System MPC15.69 r15.692026-09-262026-09-26111.0075.2395, -17.6573
ZTF ZTF18aaahouu Unknownfaded r—2021-02-122026-09-26110.97149.8988, 17.7383
ZTF ZTF18aaheytk Unknownfaded r—2018-04-062026-09-26110.96149.6634, 17.7712
ZTF ZTF18aciczxg Unknownfaded r—2018-11-122026-09-26110.71149.7537, 17.1986
ZTF ZTF19aagqizk Unknownfaded r—2018-03-302026-09-26110.99149.9575, 17.1793
ZTF ZTF19aagsfvn Unknownfaded r—2019-01-302026-09-26110.99149.9982, 17.3175
ZTF ZTF19aagsfvv Unknownfaded r—2019-01-302026-09-26110.94149.4786, 17.8863
ZTF ZTF19aaqybul Unknownfaded r—2019-04-182026-09-26221.00149.9788, 17.6958
ZTF ZTF20aaawfjd Unknownfaded r—2020-01-012026-09-26110.91149.6331, 17.6701
ZTF ZTF20abihypn Unknownfaded r—2019-01-302026-09-26221.00149.8370, 17.3927
ZTF ZTF22abjcosl Unknownfaded r—2022-09-282026-09-26110.82149.8307, 17.7948
ZTF ZTF23abiunre Unknownfaded r—2022-09-282026-09-26110.96149.9469, 17.7054
ZTF ZTF26abxsyna Solar System MPC16.08 r16.082026-09-262026-09-26111.00148.7494, 19.4717
ZTF ZTF18aaajive EclBinfaded r16.902017-12-142026-09-2631411.00143.1520, 8.0265
ZTF ZTF18aabjptt Unknownfaded r—2018-01-132026-09-26220.99143.0481, 8.1788
ZTF ZTF18acpcrju Unknownfaded r—2018-01-112026-09-26111.00142.9817, 8.0776
ZTF ZTF18acxadcy Unknownfaded r—2017-12-162026-09-2624261.00142.3985, 7.9612
ZTF ZTF19aaglxka Unknownfaded r—2017-12-162026-09-26110.99143.3520, 7.9563
ZTF ZTF19aaglxkc Unknownfaded r—2018-11-172026-09-26110.41143.2666, 7.9867
ZTF ZTF19aaglxke Unknownfaded r—2019-10-012026-09-26111.00143.2861, 7.9168
ZTF ZTF19aajdpdf Unknownfaded r—2019-02-092026-09-26110.58142.8857, 7.6738
ZTF ZTF19aajfezc Unknownfaded r—2018-04-022026-09-26221.00142.9167, 8.2149
ZTF ZTF19aajfjxg Unknownfaded r—2017-12-162026-09-26110.98143.3391, 8.0112
ZTF ZTF19aajfjxo Unknownfaded r—2017-12-162026-09-26110.98143.1673, 7.8520
ZTF ZTF19aajfjxy Unknownfaded r—2018-11-172026-09-26110.99143.3436, 7.8222
ZTF ZTF19aajfjzs Unknownfaded r—2018-11-172026-09-26110.91143.4061, 7.8191
ZTF ZTF19aajfkbz Unknownfaded r—2018-11-172026-09-26110.43143.3761, 7.8325
ZTF ZTF19aajfrri ChemPec*faded r—2017-12-162026-09-26120.96142.3873, 7.7051
ZTF ZTF19aajfrto Unknownfaded r—2019-02-092026-09-26120.90142.3555, 7.5477
ZTF ZTF19aajfrvd Starfaded r—2019-02-092026-09-2631411.00142.3546, 7.8408
ZTF ZTF19aajfrwa Unknownfaded r—2019-02-092026-09-26110.98141.7490, 7.8620
ZTF ZTF19aajgkfy Unknownfaded r—2019-02-092026-09-26110.99141.7956, 7.0247
ZTF ZTF20aahowcy Unknownfaded r—2018-11-172026-09-26110.86142.9919, 7.6573
ZTF ZTF20acgybsg Unknownfaded r—2018-11-172026-09-26110.93142.9958, 7.7071
ZTF ZTF20acgybsk Unknownfaded r—2017-12-162026-09-26110.85143.0886, 7.9045
ZTF ZTF20acsurfx Unknownfaded r—2018-11-172026-09-26110.97142.8939, 7.8415
ZTF ZTF21aaikxgm Unknownfaded r—2018-11-172026-09-26110.78142.7498, 7.9681
ZTF ZTF21aakqpjf Unknownfaded r—2018-04-022026-09-26110.90142.9396, 8.1641
ZTF ZTF21aaksoss Unknownfaded r—2021-01-062026-09-26110.96142.3515, 3.5091
ZTF ZTF21aaksost Unknownfaded r—2021-02-122026-09-26111.00142.2348, 3.5643
ZTF ZTF22aadcxbg Unknownfaded r—2019-01-302026-09-26110.76142.3307, 3.1363
ZTF ZTF26abxsyxn ChemPec*faded r—2022-10-062026-09-26110.98143.0849, 8.0295