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.
  • Tonight: Subscribe gives an RSS feed of your setup, one item a night with the picks, once the data through the night before are in (or three hours before dark). A condition (novae, rare types, something brighter than a magnitude) leaves nights without a match out, so a feed-to-email service mails only those. The plan is also JSON, for scripts and robotic telescopes. A feed's address holds your rounded site and setup: a reader or email service you give it to keeps it.

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
1–50 of 212,839 · All objects seen in the 7 nights
ObjectClassLast magRisePeakFirst seenLast seenNightsDetectionsRel.RA, DecPartner
ZTF ZTF17aabuzqb RRLyraefaded r−0.115.972017-12-082026-09-30901261.0014.1439, 20.4628
ZTF ZTF18abmofzl RRLyrae18.72 r+0.217.962018-07-222026-09-3028301.0018.1674, 15.8592
ZTF ZTF18abncqwh RRLyraefaded r−0.215.402017-12-082026-09-3053591.0017.2538, 16.2508
ZTF ZTF18abncrcm Unknown15.02 r+0.114.342018-07-032026-09-3046521.0013.2336, 20.2917
ZTF ZTF18abncrke EclBin14.34 r+0.214.262018-07-192026-09-3028290.9913.2360, 22.1568
ZTF ZTF18abncrkh Seyfert117.83 r+0.617.672018-07-032026-09-301062261.0013.4423, 22.5395
ZTF ZTF18abnurpw RRLyrae18.03 r+0.317.272017-12-082026-09-301152031.0012.2757, 19.3742
ZTF ZTF18abnzlmz EclBinfaded r−0.217.232018-07-252026-09-3019201.0015.6365, 22.4049
ZTF ZTF18abosoqk Unknown15.10 r+0.214.682018-07-032026-09-3050561.0015.4766, 21.3606
ZTF ZTF18abtldok QSO19.08 r+0.618.642018-08-162026-09-301272671.0012.4622, 20.0575
ZTF ZTF18abtmwfr Unknown14.67 r+0.214.672018-07-222026-09-30440.9913.2157, 17.1559
ZTF ZTF18abtrpxx EclBin18.34 r+0.217.942018-07-162026-09-3052611.0016.2189, 16.9063
ZTF ZTF18abungui RRLyraefaded r−0.515.152018-07-032026-09-3057851.0014.5553, 16.2992
ZTF ZTF18abunhkc Unknown18.31 r+0.115.652018-07-032026-09-3050611.0015.0278, 18.1723
ZTF ZTF18abunhkj EclBinfaded r−0.218.472017-12-082026-09-3025281.0015.0679, 18.1262
ZTF ZTF18abunjbw QSO19.21 r+0.219.212018-09-052026-09-3012141.0015.0019, 19.1983
ZTF ZTF18abvfbeh RRLyrae14.99 r+0.414.092018-07-162026-09-3058811.0015.4773, 15.9060
ZTF ZTF18abvkcxs Unknownfaded r−0.216.422018-07-312026-09-30961411.0014.2672, 21.0138
ZTF ZTF18abvspsv EclBinfaded r−0.217.932018-07-162026-09-3019191.0013.5741, 15.4818
ZTF ZTF18acevgdk UnknownAT 2021yjtfaded r−0.218.672018-09-152026-09-30951391.0014.0357, 20.1322
ZTF ZTF18acsxvok Unknown18.15 r+0.117.612018-08-042026-09-3044461.0016.7507, 16.2680
ZTF ZTF18actyunk EclBinfaded r−0.1—2018-07-032026-09-30440.9914.0312, 21.7777
ZTF ZTF18admcjpa BLLacfaded r−1.016.742018-07-032026-09-301001451.0017.2841, 18.2687
ZTF ZTF18admqjhx EclBinfaded r−0.3—2018-07-132026-09-307111.0012.2548, 15.3266
ZTF ZTF18adnhjaq RRLyrae18.55 r+0.417.712017-12-142026-09-3070981.0015.6358, 22.5633
ZTF ZTF18adnouxb EclBin16.39 r+0.316.272018-07-032026-09-3024241.0014.4891, 16.3108
ZTF ZTF19aakvjjq Unknownfaded r−0.117.352018-09-032026-09-3019241.0015.2245, 20.6746
ZTF ZTF19aazedvy QSOfaded r−0.4—2018-09-092026-09-3045571.0013.5869, 19.7966
ZTF ZTF19abcelqj QSO19.32 r+0.419.072018-09-082026-09-30711001.0015.6198, 18.4823
ZTF ZTF19abcevdu QSOfaded r−0.619.532019-06-282026-09-30771071.0013.7814, 19.1999
ZTF ZTF19abpnjfc Unknownfaded r−0.117.252018-09-212026-09-30561.0012.7641, 19.7600
ZTF ZTF19abtrfeb Seyfert1faded r−0.318.162019-07-092026-09-30821141.0014.5536, 16.0336
ZTF ZTF19abxvffs QSO19.17 r+0.518.972019-01-102026-09-30741021.0013.5694, 18.2733
ZTF ZTF19acaegvv Unknownfaded r−0.1—2019-08-092026-09-30781.0014.0119, 19.4240
ZTF ZTF19adjwzst Unknownfaded r−0.1—2019-08-262026-09-3014151.0014.2852, 18.3943
ZTF ZTF20aafdeic AGNfaded r−0.319.232018-11-062026-09-3069941.0014.7676, 18.5534
ZTF ZTF20abmdknq Unknown19.33 r+1.019.252019-09-072026-09-30691021.0013.4175, 17.4679
ZTF ZTF20acbodqi UnknownAT 2021oro19.16 r+0.618.702019-07-272026-09-30931421.0012.6852, 22.2278
ZTF ZTF21abdjbfg Unknown18.73 r+0.418.472019-08-232026-09-3061931.0014.9986, 21.8695
ZTF ZTF21abmyrlw Unknown19.61 r+0.219.612021-07-192026-09-30111.0015.0009, 16.6071
ZTF ZTF22abqshor QSO19.78 r+0.419.752022-10-272026-09-3047651.0012.6636, 19.9269
ZTF ZTF22abubvij BYDraV*18.25 r+0.217.952018-08-012026-09-309111.0012.0868, 21.7541
ZTF ZTF25abubfta Unknownfaded r−0.119.722024-09-272026-09-30220.8115.9718, 15.5568
ZTF ZTF26abrxzal AmbiguousSN Ia19.34 r—18.922026-09-032026-09-3018291.0018.5465, 16.3421
ZTF ZTF26abxmggc Solar System MPC18.28 r—18.282026-09-252026-09-30111.0017.3758, 18.7722
ZTF ZTF26abydqdu Solar System MPC17.53 r—17.532026-09-302026-09-30111.0015.3833, 19.3201
ZTF ZTF26abydqdv Solar System MPC18.48 r—18.482022-10-302026-09-30111.0015.2326, 19.3056
ZTF ZTF26abydqdw Solar System MPC18.90 r—18.902026-09-302026-09-30111.0015.7921, 19.7018
ZTF ZTF26abydqdx Solar System MPC19.02 r—19.022026-09-302026-09-30111.0015.6803, 19.2379
ZTF ZTF26abydqdz Solar System MPC17.16 r—17.162026-09-302026-09-30111.0015.0281, 16.5940