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.
  • More filters (Objects only): discovered within some nights, a redshift ceiling, a declination band, a faint limit past your saturation, one-night objects, rising ones, a reporting survey, or those an AAVSO campaign asks for. A view can be named, and its Subscribe panel gives it as a feed, as JSON and as targets for a TOM.

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. Requested marks one an AAVSO observing campaign asks observers to measure; Campaigns tonight lists the other campaign stars that are up.
  • Report an observation (object panel): where your photometry and spectra go (AAVSO for stars and novae, TNS for supernovae, CBAT for an unconfirmed TOCP entry), the name to file them under from AAVSO's VSX, and an AAVSO file formatted from what you type. Nothing is sent from the site; your observer code stays in this browser.

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, limits and cutouts
Möller et al. 2021, MNRAS 501, 3272.
Zwicky Transient Facility (ZTF): the ZTF public alert stream, through Fink
Based on observations obtained with the Samuel Oschin Telescope 48-inch and the 60-inch Telescope at the Palomar Observatory as part of the Zwicky Transient Facility project; Bellm et al. 2019, PASP 131, 018002.
Vera C. Rubin Observatory: the Rubin LSST alert stream and forced photometry, through Fink
The Vera C. Rubin Observatory Legacy Survey of Space and Time; Ivezić et al. 2019, ApJ 873, 111.
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.
AAVSO: observing campaigns that ask for observations, and VSX's names for the report helper
We acknowledge with thanks the observing campaigns of the American Association of Variable Star Observers (AAVSO), and the International Variable Star Index (VSX).
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
More filters
Clear
3,951–4,000 of 212,889 · All objects seen in the 7 nights
ObjectClassLast magRisePeakFirst seenLast seenNightsDetectionsRel.RA, DecPartner
ZTF ZTF26abydoqh Solar System MPC18.20 r—18.202026-09-302026-09-30111.00326.4991, -18.1805
ZTF ZTF26abydoqi Solar System MPC18.40 r—18.402026-09-302026-09-30111.00326.5400, -18.7719
ZTF ZTF26abydoqj Solar System MPC18.95 r—18.952026-09-302026-09-30111.00326.4887, -18.8161
ZTF ZTF26abydosb Solar System MPC18.65 r—18.652026-09-302026-09-30111.00323.8264, -13.7584
ZTF ZTF26abydose Solar System MPC19.44 r—19.442026-09-302026-09-30110.97323.8691, -13.8670
ZTF ZTF26abydozp Solar System MPC16.11 r—16.112026-09-302026-09-30111.00328.6099, -17.3386
ZTF ZTF26abydozr Solar System MPC19.55 r—19.552026-09-302026-09-30111.00328.8830, -17.6915
ZTF ZTF26abydpck Solar System MPC18.69 r—18.692026-09-302026-09-30111.00328.4794, -18.0249
ZTF ZTF26abydpcl Solar System MPC18.98 r—18.982026-09-302026-09-30111.00329.0275, -18.1490
ZTF ZTF26abydpco Solar System MPC16.67 r—16.672026-09-302026-09-30111.00324.1473, -17.3974
ZTF ZTF26abydpcp Solar System MPC18.34 r—18.342026-09-302026-09-30111.00323.7877, -17.2808
ZTF ZTF26abydpcq Solar System MPC18.74 r—18.742026-09-302026-09-30111.00323.6975, -17.9119
ZTF ZTF26abydpcr Solar System MPC18.92 r—18.922026-09-302026-09-30111.00324.0399, -17.8065
ZTF ZTF26abydpcs Solar System MPC19.30 r—19.302026-09-302026-09-30111.00323.9837, -17.3455
ZTF ZTF26abydper Solar System MPC17.45 r—17.452026-09-302026-09-30111.00326.7214, -17.2661
ZTF ZTF26abydpes Solar System MPC18.06 r—18.062026-09-302026-09-30111.00326.8963, -17.6833
ZTF ZTF26abydpip Solar System MPC17.41 r—17.412026-09-302026-09-30111.00326.1291, -18.2654
ZTF ZTF26abydpiq Solar System MPC18.49 r—18.492026-09-302026-09-30111.00325.4156, -18.3007
ZTF ZTF26abydpir Solar System MPC18.87 r—18.872026-09-302026-09-30111.00325.7971, -18.3487
ZTF ZTF26abydpis Solar System MPC18.81 r—18.812026-09-302026-09-30111.00326.0071, -18.3703
ZTF ZTF26abydpit Solar System MPC19.11 r—19.112026-09-302026-09-30110.99325.5080, -18.0377
ZTF ZTF26abydpiu Solar System MPC19.06 r—19.062026-09-302026-09-30111.00325.5472, -18.2348
ZTF ZTF26abydpjx Solar System MPC18.14 r—18.142026-09-302026-09-30111.00325.1619, -17.5134
ZTF ZTF26abydpjz Solar System MPC18.92 r—18.922023-05-222026-09-30110.94324.7274, -17.7175
ZTF ZTF26abydpka Solar System MPC19.13 r—19.132026-09-302026-09-30110.99324.3602, -17.4468
ZTF ZTF26abydpkc Solar System MPC19.56 r—19.562026-09-302026-09-30111.00324.9059, -17.7666
ZTF ZTF26abydpkn Solar System MPC16.65 r—16.652026-09-302026-09-30111.00327.3165, -18.8146
ZTF ZTF26abydpko Solar System MPC17.80 r—17.802026-09-302026-09-30111.00327.8359, -18.2097
ZTF ZTF26abydpkp Solar System MPC18.00 r—18.002026-09-302026-09-30110.00327.2377, -18.0282
ZTF ZTF26abydpkq Solar System MPC18.40 r+4.218.402026-09-302026-09-30111.00327.3862, -18.7227
ZTF ZTF26abydpkr Solar System MPC18.87 r—18.872026-09-302026-09-30111.00327.6194, -18.7624
ZTF ZTF26abydpks Solar System MPC18.83 r—18.832026-09-302026-09-30111.00327.9238, -18.8123
ZTF ZTF26abydpkt Solar System MPC19.05 r—19.052026-09-302026-09-30111.00327.8583, -18.1677
ZTF ZTF26abydple Solar System MPC16.17 r—16.172026-09-302026-09-30111.00323.5553, -18.0173
ZTF ZTF26abydplf Solar System MPC18.48 r—18.482026-09-302026-09-30111.00323.7601, -18.8291
ZTF ZTF26abydplg Solar System MPC18.58 r—18.582026-09-302026-09-30111.00323.3219, -18.3952
ZTF ZTF26abydplh Solar System MPC18.78 r—18.782026-09-302026-09-30111.00323.7715, -18.5136
ZTF ZTF26abydpli Solar System MPC18.97 r—18.972026-09-302026-09-30111.00323.3223, -18.5409
ZTF ZTF26abydplj Solar System MPC18.84 r—18.842026-09-302026-09-30111.00323.8605, -18.6420
ZTF ZTF26abydplm Solar System MPC16.40 r—16.402026-09-302026-09-30111.00327.2525, -17.8699
ZTF ZTF26abydplo Solar System MPC16.65 r+6.316.652026-09-302026-09-30111.00327.6104, -17.4535
ZTF ZTF26abydplp Solar System MPC17.71 r—17.712026-09-302026-09-30111.00327.3828, -17.6253
ZTF ZTF26abydplq Solar System MPC17.65 r—17.652026-09-112026-09-30111.00327.8675, -17.1853
ZTF ZTF26abydplr Solar System MPC18.13 r—18.132026-09-302026-09-30111.00328.0511, -17.9587
ZTF ZTF26abydplt Solar System MPC18.47 r—18.472026-09-302026-09-30111.00327.7461, -17.6200
ZTF ZTF26abydplu Solar System MPC18.79 r—18.792026-09-302026-09-30111.00327.6361, -17.7399
ZTF ZTF26abydplw Solar System MPC19.13 r—19.132026-09-302026-09-30111.00327.3022, -17.6809
ZTF ZTF26abydplx Solar System MPC19.17 r—19.172026-09-302026-09-30110.99327.7653, -17.5670
ZTF ZTF26abydpma Solar System MPC19.53 r—19.532026-09-302026-09-30111.00327.5327, -17.9445
ZTF ZTF26abydpmz Solar System MPC18.37 r+4.618.372021-09-012026-09-30111.00329.2175, -17.4561