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
1,551–1,600 of 256,283 · All objects seen in the 7 nights
ObjectClassLast magPeakFirst seenLast seenNightsDetectionsRel.RA, DecPartner
ZTF ZTF19aaeqtlz EclBinfaded r—2018-11-072026-09-26561.00124.3080, -9.0386
ZTF ZTF19aaernsm Unknown18.69 r18.692019-01-262026-09-26331.00129.5567, -7.4314
ZTF ZTF19aalcufm Star18.32 r18.322019-01-232026-09-2613131.00127.3469, -6.9416
ZTF ZTF19aamrmez Variable*18.01 r17.732018-11-202026-09-2636371.00123.7651, -8.8095
ZTF ZTF19aamrxrn EclBinfaded r—2018-12-282026-09-2621241.00126.5567, -9.2148
ZTF ZTF19aanbfiw Variable*faded r—2019-03-202026-09-2618211.00124.9149, -7.6207
ZTF ZTF19aaneiqe Starfaded r—2019-03-252026-09-26891.00123.9716, -4.4226
ZTF ZTF19aapublw LongPeriodV*_Candidatefaded r16.592018-11-272026-09-26220.95127.8145, -9.4387
ZTF ZTF19aarryqr EclBin18.04 r17.942018-11-172026-09-2626291.00126.5580, -8.4902
ZTF ZTF19aarzgsx Starfaded r—2019-04-262026-09-2660861.00123.0227, -3.6704
ZTF ZTF19accczgb EclBin16.26 r16.262017-12-082026-09-2615171.00126.8488, -7.5603
ZTF ZTF19accstwe Star18.94 r18.942018-12-292026-09-26111.00123.5357, -4.8296
ZTF ZTF19acewchn EclBin16.01 r16.012018-11-172026-09-26220.98127.6897, -9.1690
ZTF ZTF19acnqhnd Unknownfaded r—2019-01-122026-09-2651741.00122.9070, -7.5002
ZTF ZTF19acucdvr Unknown17.84 r17.842018-12-172026-09-2618221.00124.3269, -9.0652
ZTF ZTF19acvrenn Unknown18.42 r18.422019-11-252026-09-26111.00123.8444, -8.9850
ZTF ZTF19acvtqsl Star18.64 r18.642019-11-062026-09-26111.00123.4966, -9.0286
ZTF ZTF19acxxsoe EclBinfaded r—2018-11-272026-09-26221.00126.6282, -8.5891
ZTF ZTF19aczjlyv Unknownfaded r—2019-10-312026-09-2630361.00126.2161, -5.8904
ZTF ZTF20aabgepu Starfaded r—2020-01-022026-09-2636411.00123.4017, -5.6349
ZTF ZTF20aabmdce Unknown18.18 r18.182018-11-102026-09-26441.00123.6885, -5.0292
ZTF ZTF20aabmjrv EclBinfaded r18.352018-11-072026-09-2642481.00122.8081, -5.9041
ZTF ZTF20aafzeut Unknown18.47 r18.252020-01-022026-09-26691031.00123.8221, -5.5605
ZTF ZTF20aahmwvx Unknownfaded r—2019-04-252026-09-26111.00124.1356, -8.2949
ZTF ZTF20aahmzvt Unknownfaded r—2020-01-022026-09-2646691.00124.6703, -5.5819
ZTF ZTF20aaklvwz Unknownfaded r—2019-01-042026-09-2660961.00125.7596, -9.5322
ZTF ZTF20accmutv SupernovaSN IIPfaded r—2018-11-172026-09-26111.00126.0994, -3.4886
ZTF ZTF20acmudjj EclBinfaded r14.422018-11-192026-09-266121.00123.7239, -2.7224
ZTF ZTF20acnekir Unknownfaded r—2018-12-282026-09-2647481.00127.3946, -9.9246
ZTF ZTF20acnvtry Unknownfaded r—2018-11-122026-09-26111.00129.5733, -7.3633
ZTF ZTF20acrarxj Unknown18.61 r18.612020-11-162026-09-26451.00123.9330, -2.7154
ZTF ZTF20actqwwu Unknownfaded r—2020-03-042026-09-2624291.00127.1916, -8.0173
ZTF ZTF20actzezc QSOfaded r—2018-12-282026-09-2652741.00128.4390, -6.4801
ZTF ZTF20acubxif Unknown18.24 r18.072020-10-122026-09-26221.00124.0995, -2.6629
ZTF ZTF20acuhuxm Unknown18.92 r18.342020-11-292026-09-2667991.00124.0753, -7.7975
ZTF ZTF20acuoacn SupernovaSN Ia-91bg-likefaded r—2018-11-172026-09-26111.00123.8522, -6.9578
ZTF ZTF20acwmqqq EclBinfaded r—2020-01-112026-09-26110.61125.3815, -4.5905
ZTF ZTF20acwvjkc RRLyrae17.72 r17.722018-11-202026-09-26111.00125.7892, -7.9853
ZTF ZTF20acwvjsv Unknown17.33 r17.332019-12-162026-09-26111.00123.2085, -3.9949
ZTF ZTF20acwvjtp EclBin17.70 r17.702018-11-172026-09-26111.00127.8765, -6.4140
ZTF ZTF20acwvjwk EclBinfaded r—2018-12-292026-09-26111.00125.1267, -7.0895
ZTF ZTF20acwvjws EclBinfaded r—2018-11-172026-09-26111.00128.0935, -7.9204
ZTF ZTF20acwvjwy EclBin18.74 r18.742018-11-172026-09-26111.00125.1032, -4.6130
ZTF ZTF20acwvjya Unknown18.87 r18.872018-11-172026-09-26111.00124.1248, -4.5182
ZTF ZTF20acwvkah EclBin19.02 r19.022019-02-262026-09-26111.00126.6670, -9.7999
ZTF ZTF20acwvkin EclBin_Candidate18.10 r18.102018-11-172026-09-26111.00126.1161, -9.7826
ZTF ZTF20acwvkjm Unknownfaded r—2019-10-272026-09-26111.00123.4501, -4.4648
ZTF ZTF20acwvkjt RRLyrae18.33 r18.332018-11-172026-09-26111.00123.1994, -6.6936
ZTF ZTF20acwvkvg LongPeriodV*15.20 r15.202018-11-172026-09-26111.00127.0082, -7.3910
ZTF ZTF20acwvkwy EclBinfaded r—2019-10-272026-09-26111.00123.7018, -7.8342