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
2,551–2,600 of 214,524 · All objects seen in the 7 nights
ObjectClassLast magRisePeakFirst seenLast seenNightsDetectionsRel.RA, DecPartner
ZTF ZTF19aaptorn Unknownfaded r−0.218.712019-03-052026-09-2933491.00123.1685, 2.0656
ZTF ZTF19aarqqsy Starfaded r−0.1—2019-04-252026-09-2924351.00123.0873, 7.5991
ZTF ZTF19aarqrms EclBin18.77 r+0.118.092019-04-252026-09-2955861.00121.6311, 7.1613
ZTF ZTF19aasxozj Starfaded r−0.1—2019-04-292026-09-2921221.00123.1842, 7.5366
ZTF ZTF19aatqcut Unknownfaded r−0.118.742019-04-082026-09-2914151.00121.8341, 3.7652
ZTF ZTF19aatqdad Unknown19.16 r+0.319.162020-10-132026-09-29441.00121.8323, 0.9524
ZTF ZTF19aatqdfw Unknown18.86 r+0.318.612019-05-042026-09-2952911.00121.6934, 3.2389
ZTF ZTF19aatqmro Seyfert1AT 2020uzi19.19 r+0.419.162018-11-082026-09-2937581.00122.5839, 7.5708
ZTF ZTF19aatqnea Unknownfaded r−0.318.502019-05-042026-09-2956861.00120.9045, 4.7013
ZTF ZTF19aatwkda Unknown18.86 r+0.118.862018-11-072026-09-29331.00125.5447, 3.2059
ZTF ZTF19aatwlit Unknownfaded r−0.317.672018-12-282026-09-2956811.00125.9609, 3.8216
ZTF ZTF19acajkvs Unknownfaded r−0.216.922018-04-022026-09-2916170.99123.6351, 1.9998
ZTF ZTF19acbmzez Unknownfaded r−0.115.892018-11-192026-09-2936611.00121.4094, 1.4176
ZTF ZTF19acboqiu Unknownfaded r−0.1—2019-03-012026-09-2913151.00120.9590, 1.0004
ZTF ZTF19acboqjt Unknown18.10 r+0.118.052019-01-082026-09-29220.76121.9038, 0.9805
ZTF ZTF19accstvj Unknown18.78 r+0.218.782018-12-292026-09-2930401.00120.7992, 6.6174
ZTF ZTF19achtdnu Unknownfaded r−0.1—2019-09-222026-09-29330.83123.9190, 1.8867
ZTF ZTF19achtegl QSOfaded r−0.418.802019-05-042026-09-29601111.00123.5017, 1.5752
ZTF ZTF19acpybym Unknownfaded r−0.118.702019-02-122026-09-29440.00120.6350, 1.5096
ZTF ZTF19acpyfbl Unknown18.56 r+0.218.562019-02-092026-09-2923311.00125.4041, 2.8852
ZTF ZTF19acpykkv Unknown18.43 r+0.718.432019-02-092026-09-2920251.00121.3014, 1.2527
ZTF ZTF19acpzsfx Unknown18.53 r+0.118.412019-05-042026-09-2916171.00125.1764, 3.4967
ZTF ZTF19acpzumi Unknownfaded r−0.1—2019-11-072026-09-29220.99127.0103, 0.8557
ZTF ZTF19acpzygw Unknown19.19 r+0.119.192018-11-172026-09-29110.94122.3753, 7.2025
ZTF ZTF19acqarod EclBinfaded r−0.219.522019-02-202026-09-29671.00120.3861, 6.2807
ZTF ZTF19acqcmfo Unknown18.47 r+0.118.462018-11-082026-09-29661.00123.4984, 6.9463
ZTF ZTF19acqdqyp Unknownfaded r−0.1—2019-11-072026-09-29791.00123.3120, 6.0859
ZTF ZTF19acvdlml Unknownfaded r−0.1—2019-02-122026-09-2919190.53124.0433, 1.6318
ZTF ZTF19acvdmnw Unknownfaded r−0.118.792018-11-192026-09-2941531.00125.9561, 2.3605
ZTF ZTF19acxodqr Unknownfaded r−0.115.182018-11-172026-09-2935481.00121.7241, 7.6968
ZTF ZTF19adfxmho Unknownfaded r−0.115.632018-11-192026-09-2921271.00120.5555, 4.6467
ZTF ZTF19adgjuml QSOfaded r−0.619.102018-11-052026-09-29791361.00122.2802, 5.4489
ZTF ZTF19adgjvol Unknownfaded r−0.216.542019-02-092026-09-2924261.00120.7563, 2.2590
ZTF ZTF19adhdmwu Unknownfaded r−0.117.732018-12-292026-09-29701111.00125.3096, 3.3690
ZTF ZTF20aabgfsl Unknownfaded r−0.118.262020-01-022026-09-2931441.00122.5069, 2.5032
ZTF ZTF20aabjbce Unknownfaded r−0.1—2019-10-142026-09-29110.79122.0648, 2.9816
ZTF ZTF20aabjbco QSOfaded r−0.3—2019-05-042026-09-2955751.00123.1132, 7.9592
ZTF ZTF20aabkjvp Unknown17.55 r+0.217.552018-11-132026-09-2962961.00126.9275, 1.0451
ZTF ZTF20aablyaw RRLyraefaded r−0.1—2018-11-072026-09-29440.97123.0247, 7.9799
ZTF ZTF20aabnigw QSOfaded r−0.919.062019-05-042026-09-29721261.00124.9629, 4.3904
ZTF ZTF20aabofik Unknownfaded r−0.115.222018-12-132026-09-2912150.96121.4144, 3.1834
ZTF ZTF20aacmpmg Unknown18.96 r+0.718.312019-05-042026-09-29791451.00124.1728, 2.4343
ZTF ZTF20aaedomn Unknown15.96 r+0.115.962018-11-172026-09-29110.83122.7164, 3.4725
ZTF ZTF20aaeeaxx EclBin18.88 r+0.218.882017-12-142026-09-29881.00121.2609, 7.0647
ZTF ZTF20aaeebao Star18.44 r+0.118.442018-12-292026-09-29111.00122.2278, 3.8764
ZTF ZTF20aamahcc Unknown16.70 r+0.116.702018-11-082026-09-29331.00123.3822, 5.1973
ZTF ZTF20aasdgqw Unknownfaded r−0.1—2020-03-042026-09-2913141.00123.5100, 5.5041
ZTF ZTF20aauyoii Unknownfaded r−0.218.852020-04-162026-09-2940521.00122.2167, 2.1275
ZTF ZTF20acabdct Seyfert2AT 2020urh17.61 r+0.217.252018-11-172026-09-2958841.00121.4406, 7.5906
ZTF ZTF20ackigpo Seyfert218.83 r+0.218.832019-05-042026-09-2938451.00124.5613, 1.3742