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.
  • Where your data count: the surveys measure their own objects every few nights, but a TNS or CBAT object gets only ATLAS's photometry, and only while it is brighter than 19. Unconfirmed marks one reported on a single night in the last two weeks: a detection confirms it, and a deep non-detection is news too. No recent data marks one seen on two or more nights that nothing has measured for four nights or more: a magnitude fills the gap in its light curve.

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.

Everything here is also JSON: Data and API has the public API, the feeds, the exports and how to cite the data.

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
3,501–3,550 of 212,839 · All objects seen in the 7 nights
ObjectClassLast magRisePeakFirst seenLast seenNightsDetectionsRel.RA, DecPartner
ZTF ZTF21abjnswx Unknownfaded r−0.218.842020-10-082026-09-3032341.00333.8208, -20.7470
ZTF ZTF21ablvwvt Unknownfaded r−0.119.182021-06-052026-09-3025281.00332.8100, -17.5619
ZTF ZTF21abrbiif Unknownfaded r−0.319.832021-06-052026-09-3031311.00331.2290, -13.8402Rubin
ZTF ZTF21abtlxfz AGNfaded r−0.319.512020-10-142026-09-30721041.00330.6354, -15.2470Rubin
ZTF ZTF21acgnnly Unknownfaded r−0.117.762019-10-292026-09-3013131.00330.7086, -13.6359
ZTF ZTF21acgnouq Unknownfaded r−0.719.362021-06-212026-09-3063961.00332.5054, -18.0850
ZTF ZTF21acgntxo Unknown18.65 r+0.218.652021-10-072026-09-30111.00333.1431, -16.1439
ZTF ZTF21acgovpe Star15.41 r+0.115.412020-10-162026-09-30550.98330.8274, -14.4463
ZTF ZTF21ackngdr Unknownfaded r−0.116.592019-01-052026-09-3045501.00335.6389, -19.4378
ZTF ZTF22aavdsyf Unknownfaded r−1.219.702019-06-282026-09-3063891.00330.7425, -13.5772Rubin
ZTF ZTF23aanpyrd QSO19.39 r+0.219.112022-08-172026-09-3052701.00333.0431, -18.4604Rubin
ZTF ZTF23aaqyrrb Unknown19.31 r+1.019.182023-06-152026-09-3065921.00334.7851, -18.7492Rubin
ZTF ZTF23aaykkmu Unknown17.52 r+0.217.522018-09-032026-09-3020221.00336.7340, -20.2839
ZTF ZTF24aaptfwh Solar System MPC18.23 r—18.232024-05-312026-09-30111.00335.6695, -18.3534
ZTF ZTF24abwmcdk AGNfaded r−0.2—2020-07-052026-09-3012131.00330.2420, -15.5379
ZTF ZTF26abydnfc Solar System MPC19.01 r—19.012026-09-302026-09-30111.00331.6138, -19.2818
ZTF ZTF26abydnii Solar System MPC18.10 r—18.102026-09-302026-09-30111.00332.7731, -19.3930
ZTF ZTF26abydnij Solar System MPC18.00 r—18.002026-09-302026-09-30111.00332.8903, -19.1435
ZTF ZTF26abydnik Solar System MPC19.14 r—19.142026-09-302026-09-30111.00332.4115, -19.3457
ZTF ZTF26abydnil Solar System MPC19.11 r—19.112026-09-302026-09-30111.00332.5759, -19.8832
ZTF ZTF26abydniv Solar System MPC18.14 r—18.142026-09-302026-09-30111.00333.2122, -14.5902
ZTF ZTF26abydniy Solar System MPC19.02 r—19.022026-09-302026-09-30110.99333.2169, -14.8973
ZTF ZTF26abydnjb Solar System MPC19.38 r—19.382026-09-302026-09-30111.00332.5732, -14.2061
ZTF ZTF26abydnms Solar System MPC16.62 r—16.622026-09-302026-09-30111.00332.7636, -16.2350
ZTF ZTF26abydnmt Solar System MPC18.14 r—18.142026-09-302026-09-30111.00332.8802, -16.2864
ZTF ZTF26abydnmu Solar System MPC18.76 r+3.818.762026-09-302026-09-30111.00332.9146, -16.4684
ZTF ZTF26abydnmw Solar System MPC19.44 r—19.442026-09-302026-09-30111.00332.7009, -16.3351
ZTF ZTF26abydnmx Solar System MPC19.82 r—19.822026-09-302026-09-30111.00332.7061, -16.3523
ZTF ZTF26abydnmy Solar System MPC17.97 r—17.972026-09-302026-09-30111.00330.6247, -16.7974
ZTF ZTF26abydnmz Solar System MPC18.12 r—18.122026-09-302026-09-30111.00331.1983, -16.5890
ZTF ZTF26abydnna Solar System MPC18.07 r—18.072026-09-302026-09-30111.00330.7650, -16.6120
ZTF ZTF26abydnnb Solar System MPC18.76 r—18.762026-09-302026-09-30111.00331.0331, -16.3836
ZTF ZTF26abydnnd Solar System MPC18.96 r—18.962026-09-302026-09-30111.00330.9861, -16.5448
ZTF ZTF26abydnnf Solar System MPC19.20 r—19.202026-09-302026-09-30111.00330.4603, -16.4553
ZTF ZTF26abydnnn Solar System MPC14.93 r—14.932022-06-082026-09-30111.00331.6307, -20.2250
ZTF ZTF26abydnnq Solar System MPC17.11 r—17.112026-09-302026-09-30111.00332.1687, -20.4062
ZTF ZTF26abydnnr Solar System MPC18.94 r—18.942026-09-302026-09-30111.00332.1380, -20.5017
ZTF ZTF26abydnns Solar System MPC19.15 r—19.152026-09-302026-09-30111.00331.5457, -20.4913
ZTF ZTF26abydnpd Solar System MPC17.99 r—17.992026-09-302026-09-30111.00331.7356, -13.8159
ZTF ZTF26abydnpe Solar System MPC18.89 r—18.892026-09-302026-09-30111.00331.7303, -13.3668
ZTF ZTF26abydnpf Solar System MPC18.86 r+3.018.862026-09-302026-09-30111.00331.5735, -13.9857
ZTF ZTF26abydnps Solar System MPC17.89 r—17.892026-09-302026-09-30111.00334.4969, -20.1943
ZTF ZTF26abydnpt Solar System MPC18.90 r—18.902026-09-302026-09-30111.00335.1579, -20.5052
ZTF ZTF26abydnpu Solar System MPC19.09 r—19.092026-09-302026-09-30111.00334.3813, -20.0345
ZTF ZTF26abydnsa Solar System MPC14.29 r—14.292026-09-302026-09-30111.00332.2121, -14.7093
ZTF ZTF26abydnsb Solar System MPC15.05 r—15.052026-09-302026-09-30111.00331.7467, -14.3044
ZTF ZTF26abydnsc Solar System MPC18.28 r—18.282026-09-302026-09-30111.00331.8997, -14.3185
ZTF ZTF26abydnsg Solar System MPC19.17 r—19.172026-09-302026-09-30111.00331.9950, -14.2583
ZTF ZTF26abydnsj Solar System MPC19.53 r—19.532026-09-302026-09-30111.00331.9672, -14.3773
ZTF ZTF26abydnum Solar System MPC19.20 r—19.202026-09-302026-09-30111.00331.4625, -16.1663