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
3,401–3,450 of 212,839 · All objects seen in the 7 nights
ObjectClassLast magRisePeakFirst seenLast seenNightsDetectionsRel.RA, DecPartner
ZTF ZTF26abydqau Solar System MPC18.80 r—18.802026-09-302026-09-30111.00343.9291, -17.2125
ZTF ZTF26abydqav Solar System MPC18.76 r—18.762026-09-302026-09-30111.00344.0327, -17.8629
ZTF ZTF26abydqaw Solar System MPC18.99 r—18.992026-09-302026-09-30111.00344.5174, -17.4433
ZTF ZTF26abydqax Solar System MPC18.94 r—18.942026-09-302026-09-30110.08344.4598, -17.8952
ZTF ZTF26abydqay Solar System MPC19.56 r—19.562026-09-302026-09-30110.98344.4504, -17.6646
ZTF ZTF18abtiysw RRLyrae18.97 r+0.217.832018-06-102026-09-3041631.00329.9062, -16.7320
ZTF ZTF18abuegjn EclBin17.92 r+0.216.752018-06-102026-09-30851411.00329.7024, -17.8299Rubin
ZTF ZTF18abvbntm RRLyraefaded r−0.215.802018-06-102026-09-30871831.00329.5956, -18.1397
ZTF ZTF18abvbnto RRLyraefaded r−0.316.992018-06-162026-09-30891551.00329.8492, -18.0329Rubin
ZTF ZTF18abvbntu EclBinfaded r−0.118.442018-06-102026-09-3053691.00329.8144, -18.0042Rubin
ZTF ZTF18abvwxbg EclBinfaded r−0.216.472018-06-282026-09-3043491.00335.4492, -17.5489
ZTF ZTF18abvwxek RRLyraefaded r−0.316.532018-06-102026-09-3056861.00330.2913, -17.1587Rubin
ZTF ZTF18abweroc Unknown15.00 r+0.314.482018-06-102026-09-3063981.00336.7176, -19.4196
ZTF ZTF18accpmna RRLyraefaded r−0.314.762018-06-102026-09-3048571.00329.5883, -14.0116
ZTF ZTF18acdibxc RRLyraefaded r−0.116.232018-06-102026-09-3056691.00330.2536, -14.9659Rubin
ZTF ZTF18acdjgjk EclBin17.85 r+0.116.232018-06-102026-09-3022251.00330.1803, -18.3966
ZTF ZTF18acdjskk RRLyraefaded r−0.417.992018-06-102026-09-3055721.00331.5957, -15.7327Rubin
ZTF ZTF18acdjskq RRLyraefaded r−0.217.432018-06-102026-09-3074991.00331.9628, -15.2495Rubin
ZTF ZTF18acdjvfb RRLyraefaded r−0.214.842018-06-102026-09-3040461.00336.4138, -18.2398
ZTF ZTF18acehxtc RRLyrae18.40 r+0.217.522018-06-102026-09-301012081.00329.8197, -20.6003Rubin
ZTF ZTF18acehxxs Variable*faded r−0.116.862018-06-162026-09-3033410.98329.6332, -14.6525
ZTF ZTF18acetmqp EclBin19.30 r+0.319.302018-06-162026-09-30111.00331.8787, -13.3813
ZTF ZTF18acetzdb Unknownfaded r−0.1—2018-07-182026-09-30220.82329.5772, -13.6500Rubin
ZTF ZTF18acetzde EclBinfaded r−0.217.402018-11-212026-09-3046541.00330.2399, -13.6086
ZTF ZTF18aceudjx RRLyraefaded r−0.316.892018-06-162026-09-30841291.00334.0444, -20.6279Rubin
ZTF ZTF18acheerw RRLyrae_Candidate19.15 r+0.218.092018-06-282026-09-3061761.00332.7153, -13.6826Rubin
ZTF ZTF18achfhai RRLyraefaded r−0.416.752018-06-102026-09-30891771.00336.6819, -20.0941
ZTF ZTF18acmfgqu RRLyraefaded r−0.2—2018-06-162026-09-30221.00331.9951, -17.7948
ZTF ZTF18acmfhdl EclBinfaded r−0.117.942018-06-102026-09-3031341.00330.8300, -13.7494Rubin
ZTF ZTF18acmfhdv RRLyraefaded r−0.415.342018-06-102026-09-30871291.00331.8775, -16.3342Rubin
ZTF ZTF18actwxbg AGN_Candidatefaded r−0.418.312018-08-082026-09-3068871.00332.3902, -18.1871
ZTF ZTF18actwxfx EclBinfaded r−0.215.222018-06-282026-09-3012120.99334.8572, -18.1131
ZTF ZTF18actwxfz RRLyrae17.21 r+0.216.032018-06-102026-09-3062801.00335.0034, -18.3779
ZTF ZTF18actwxge EclBin16.83 r+0.115.712018-06-282026-09-3027301.00331.4702, -19.1992
ZTF ZTF18actwxjf EclBin_Candidate18.41 r+0.218.182018-09-052026-09-3043491.00330.7626, -14.6419Rubin
ZTF ZTF18actwxka RRLyraefaded r−0.116.292018-06-102026-09-30661.00331.1959, -17.8972Rubin
ZTF ZTF18actwxki Unknownfaded r−0.2—2018-06-102026-09-3011111.00330.5330, -15.4234
ZTF ZTF18actxway Unknownfaded r−0.117.192018-06-102026-09-3069861.00330.5467, -14.5611
ZTF ZTF18acxhnjd RRLyraefaded r−0.115.362018-06-102026-09-3048561.00332.3836, -19.2404
ZTF ZTF18acxhonq EclBinfaded r−0.117.972018-08-012026-09-3024261.00331.1690, -20.1099
ZTF ZTF18adoykrv BLLacfaded r−0.617.732018-08-012026-09-301162251.00332.8504, -13.4694Rubin
ZTF ZTF18adposle RRLyrae18.58 r+0.417.822018-06-102026-09-3061761.00335.4964, -19.7037
ZTF ZTF18adpospq LongPeriodV*16.22 r+0.116.132018-06-102026-09-30551.00331.7425, -19.9466
ZTF ZTF18adposps RRLyrae16.32 r+0.215.772018-06-102026-09-3052611.00330.5148, -18.4543
ZTF ZTF18adpotae RRLyrae19.08 r+0.218.792018-06-102026-09-3023231.00331.1348, -20.4386Rubin
ZTF ZTF18adpoudz RRLyraefaded r−0.315.512018-06-102026-09-3047521.00332.7972, -18.6867
ZTF ZTF18adpoueo Variable*faded r−0.515.802018-06-282026-09-3051761.00330.5712, -19.7764
ZTF ZTF18adpougs RRLyrae16.93 r+0.115.422018-06-102026-09-3061761.00334.4948, -18.4027
ZTF ZTF18adpovgk RRLyrae18.84 r+0.417.882018-06-102026-09-3067881.00332.0421, -16.4460Rubin
ZTF ZTF18adpowuf RRLyraefaded r−0.315.862018-06-102026-09-30781091.00332.5448, -14.9055Rubin