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
2,101–2,150 of 214,523 · All objects seen in the 7 nights
ObjectClassLast magRisePeakFirst seenLast seenNightsDetectionsRel.RA, DecPartner
ZTF ZTF26abyaomk Solar System MPC16.67 r—16.672026-09-292026-09-29111.00122.0470, -12.4517
ZTF ZTF17aaajazw RRLyraefaded r−0.117.882017-12-122026-09-2911121.00137.6211, 31.9967
ZTF ZTF17aaatdot EclBinfaded r−0.716.902017-11-212026-09-2915171.00135.1056, 32.4697
ZTF ZTF17aabiewn RSCVnV*faded r−0.116.842017-12-172026-09-2923301.00134.6153, 33.1579
ZTF ZTF17aaclerd Unknownfaded r−0.314.452017-12-092026-09-2918261.00133.0438, 30.5549
ZTF ZTF17aaclmup RRLyraefaded r−0.315.432017-11-212026-09-2920261.00131.8927, 31.0567
ZTF ZTF17aacmgyz RRLyraefaded r−0.217.402017-11-162026-09-2921311.00130.7870, 31.2293
ZTF ZTF17aacmgzb RRLyrae17.99 r+0.317.842017-11-012026-09-2914191.00131.0321, 30.7466
ZTF ZTF17aacmlru EclBin18.63 r+0.118.122017-11-162026-09-2919211.00133.7896, 31.5427
ZTF ZTF17aacmnns RRLyraefaded r−0.317.472017-11-162026-09-2929371.00132.1091, 36.3354
ZTF ZTF17aacmnyh RRLyraefaded r−0.117.302017-11-162026-09-2916211.00130.6571, 32.8106
ZTF ZTF17aactfpr RRLyrae14.94 r+0.514.552017-10-192026-09-2956921.00131.7457, 29.8244
ZTF ZTF17aactgbz RRLyraefaded r−0.216.032017-11-012026-09-2928341.00132.5746, 33.5560
ZTF ZTF17aacvvxf RRLyraefaded r−0.117.702017-10-192026-09-2911151.00132.4329, 32.9964
ZTF ZTF17aacvwcb RRLyraefaded r−0.316.612017-10-192026-09-2941641.00135.0156, 29.9527
ZTF ZTF17aacvwss RRLyrae17.87 r+0.317.172017-10-192026-09-2925371.00132.8181, 34.0576
ZTF ZTF17aacvxbk EclBin17.57 r+0.317.432017-10-192026-09-2917231.00131.9979, 32.3402
ZTF ZTF17aacvxlg RRLyraefaded r−0.116.672017-10-192026-09-29611081.00132.4594, 36.9332
ZTF ZTF17aacvxta RRLyraefaded r−0.317.202017-10-192026-09-2928491.00130.2452, 32.0810
ZTF ZTF18aaacrgw Unknownfaded r−0.1—2017-11-212026-09-29790.99131.6413, 33.4744
ZTF ZTF18aaaxklz EclBin18.99 r+0.318.852017-10-192026-09-2915181.00131.1484, 36.8409
ZTF ZTF18aaaxkrz EclBin18.37 r+0.117.832017-12-012026-09-2923341.00131.5541, 33.4822
ZTF ZTF18aabkjjl EclBinfaded r−0.216.812017-12-122026-09-2935541.00131.3389, 36.7224
ZTF ZTF18aachnke QSOfaded r−0.318.602017-11-192026-09-2930381.00137.5162, 31.0565
ZTF ZTF18aacpuqj QSO18.44 r+0.318.442019-10-292026-09-2934401.00136.2871, 30.9660
ZTF ZTF18aacpzyi QSO19.01 r+0.218.462017-12-172026-09-2938491.00135.6983, 30.6892
ZTF ZTF18aacrfjp Unknown18.95 r+0.218.952017-11-192026-09-29551.00136.3129, 29.6619
ZTF ZTF18aacrheg QSO18.73 r+0.618.292018-11-082026-09-2949881.00135.8569, 30.0904
ZTF ZTF18aacrjca QSOAT 2019hcs19.11 r+0.719.112018-10-062026-09-2922231.00135.6772, 30.3847
ZTF ZTF18aacssal QSOAT 2021agdt19.17 r+0.318.732019-05-022026-09-2943821.00130.7389, 35.5418
ZTF ZTF18aacvpei QSO18.97 r+0.318.142018-11-062026-09-2943681.00130.7190, 34.3928
ZTF ZTF18aaczjes QSOfaded r−0.518.632018-12-122026-09-2949911.00134.7731, 31.0896
ZTF ZTF18aadfewn QSOfaded r−0.218.182020-02-262026-09-2948871.00134.8925, 32.7818
ZTF ZTF18aadiutn QSOfaded r−0.4—2020-01-012026-09-2946601.00128.9973, 34.4874
ZTF ZTF18aadnrxt QSO19.76 r+0.419.052019-04-072026-09-2938641.00134.1534, 30.8961
ZTF ZTF18aadomva QSO19.15 r+0.319.152018-09-192026-09-29441.00129.4508, 31.7111
ZTF ZTF18aadpnia QSOfaded r−1.619.482019-02-082026-09-2936611.00133.7303, 30.0542
ZTF ZTF18aadrcgn QSOfaded r−0.519.022018-12-092026-09-2922371.00131.9519, 31.9537
ZTF ZTF18aadtgcb QSO19.42 r+0.319.252018-11-182026-09-2947611.00129.2923, 35.0108
ZTF ZTF18aaedoey QSOfaded r−0.419.452019-12-292026-09-2930481.00133.9327, 32.2995
ZTF ZTF18aaedokj QSO19.44 r+0.719.442019-02-082026-09-2912121.00133.7934, 31.6759
ZTF ZTF18aaedzgf QSO19.19 r+0.519.082019-12-292026-09-2930381.00135.2717, 32.8630
ZTF ZTF18aaeecbt Starfaded r−0.116.792018-02-242026-09-29571.00130.2251, 33.9272
ZTF ZTF18aaepxjq Starfaded r−0.1—2018-11-172026-09-29221.00130.2863, 32.8245
ZTF ZTF18aaeqbsp QSOfaded r−0.619.372018-11-062026-09-2938651.00134.2250, 32.7491
ZTF ZTF18aallwes Unknown16.15 r+0.116.152017-12-172026-09-29220.98133.1291, 35.8486
ZTF ZTF18aaqjask Unknownfaded r−0.718.892018-05-052026-09-2922361.00131.6695, 32.8175
ZTF ZTF18aawwfep Seyfert118.90 r+0.418.902017-10-192026-09-29221.00133.6740, 30.9653
ZTF ZTF18accnlgr Star19.08 r+0.218.692018-05-252026-09-2915171.00130.4920, 35.5454
ZTF ZTF18acdvrho Unknown18.35 r+0.218.242017-12-172026-09-2932411.00133.4773, 30.0754