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
3,851–3,900 of 212,889 · All objects seen in the 7 nights
ObjectClassLast magRisePeakFirst seenLast seenNightsDetectionsRel.RA, DecPartner
ZTF ZTF26abydmza Solar System MPC19.16 r—19.162026-09-302026-09-30111.00324.4964, -15.3465
ZTF ZTF26abydmzb Solar System MPC18.99 r—18.992026-09-302026-09-30110.99324.8677, -15.6141
ZTF ZTF26abydmzc Solar System MPC17.23 r—17.232026-09-302026-09-30111.00326.8320, -20.5316
ZTF ZTF26abydmzd Solar System MPC18.44 r—18.442026-09-302026-09-30111.00326.5626, -20.0500
ZTF ZTF26abydmze Solar System MPC19.41 r—19.412026-09-302026-09-30110.98326.4522, -20.0764
ZTF ZTF26abydmzg Solar System MPC14.32 r—14.322026-09-302026-09-30111.00325.3466, -16.6168
ZTF ZTF26abydmzl Solar System MPC18.26 r—18.262026-09-302026-09-30111.00325.5110, -16.2272
ZTF ZTF26abydnbr Solar System MPC17.20 r—17.202026-09-302026-09-30111.00328.3184, -20.2188
ZTF ZTF26abydnbu Solar System MPC16.67 r—16.672026-09-302026-09-30111.00324.7328, -16.3537
ZTF ZTF26abydnbv Solar System MPC18.45 r—18.452026-09-302026-09-30111.00328.6297, -19.4650
ZTF ZTF26abydnbw Solar System MPC17.53 r—17.532026-09-302026-09-30111.00324.4999, -16.8358
ZTF ZTF26abydnby Solar System MPC19.35 r—19.352026-09-302026-09-30111.00328.8429, -19.2645
ZTF ZTF26abydnca Solar System MPC19.34 r—19.342026-09-302026-09-30111.00328.3465, -19.0871
ZTF ZTF26abydncb Solar System MPC18.26 r—18.262026-09-302026-09-30111.00324.6953, -16.8638
ZTF ZTF26abydncc Solar System MPC18.85 r—18.852026-09-302026-09-30111.00328.5007, -20.1077
ZTF ZTF26abydnce Solar System MPC18.41 r—18.412026-09-302026-09-30111.00324.6569, -16.4508
ZTF ZTF26abydncf Solar System MPC19.22 r—19.222026-09-302026-09-30111.00328.7892, -19.8344
ZTF ZTF26abydncg Solar System MPC18.93 r—18.932026-09-302026-09-30111.00324.4184, -16.8118
ZTF ZTF26abydnch Solar System MPC18.87 r—18.872026-09-302026-09-30111.00328.8377, -20.1990
ZTF ZTF26abydnci Solar System MPC18.99 r—18.992026-09-302026-09-30111.00324.4902, -16.8142
ZTF ZTF26abydncl Solar System MPC19.38 r—19.382026-09-302026-09-30111.00324.3913, -16.4281
ZTF ZTF26abydncm Solar System MPC19.41 r+3.419.412026-09-302026-09-30111.00324.6888, -16.7066
ZTF ZTF26abydncn Solar System MPC19.58 r—19.582026-09-302026-09-30111.00324.9267, -16.1317
ZTF ZTF26abydndo Solar System MPC18.97 r—18.972026-09-302026-09-30111.00323.3396, -20.4027
ZTF ZTF26abydnds Solar System MPC18.06 r—18.062026-09-302026-09-30110.98323.3050, -14.7824
ZTF ZTF26abydndt Solar System MPC18.31 r—18.312026-09-302026-09-30111.00322.8335, -14.4886
ZTF ZTF26abydndv Solar System MPC19.05 r—19.052026-09-302026-09-30111.00323.1064, -14.2290
ZTF ZTF26abydndw Solar System MPC19.27 r+3.519.272026-09-302026-09-30111.00322.7928, -14.6464
ZTF ZTF26abydndy Solar System MPC15.52 r—15.522026-09-302026-09-30111.00327.4487, -20.0947
ZTF ZTF26abydndz Solar System MPC18.78 r—18.782026-09-302026-09-30111.00327.3467, -20.0361
ZTF ZTF26abydner Solar System MPC17.00 r—17.002026-09-302026-09-30111.00326.0282, -14.9337
ZTF ZTF26abydnes Solar System MPC18.33 r—18.332026-09-302026-09-30111.00325.9702, -14.8808
ZTF ZTF26abydnet Solar System MPC18.95 r—18.952026-09-302026-09-30111.00325.3057, -14.4728
ZTF ZTF26abydneu Solar System MPC19.04 r—19.042026-09-302026-09-30111.00325.4819, -14.3491
ZTF ZTF26abydnfe Solar System MPC17.16 r—17.162026-09-302026-09-30111.00323.7998, -19.1540
ZTF ZTF26abydnff Solar System MPC17.90 r—17.902026-09-302026-09-30111.00323.3693, -19.1680
ZTF ZTF26abydnfj Solar System MPC18.87 r—18.872026-09-302026-09-30110.98323.6356, -19.3621
ZTF ZTF26abydngh Solar System MPC17.41 r—17.412026-09-302026-09-30111.00325.4169, -19.7807
ZTF ZTF26abydngi Solar System MPC18.41 r—18.412026-09-302026-09-30111.00325.5573, -19.2038
ZTF ZTF26abydngj Solar System MPC18.60 r—18.602026-09-302026-09-30111.00325.9845, -19.4116
ZTF ZTF26abydngk Solar System MPC19.02 r—19.022026-09-302026-09-30111.00326.1003, -19.4904
ZTF ZTF26abydngl Solar System MPC19.17 r—19.172026-09-302026-09-30111.00326.0989, -19.7743
ZTF ZTF26abydngm Solar System MPC19.10 r—19.102026-09-302026-09-30111.00326.0527, -19.3992
ZTF ZTF26abydngn Solar System MPC18.99 r—18.992026-09-302026-09-30111.00326.0138, -19.7995
ZTF ZTF26abydngp Solar System MPC15.85 r—15.852026-09-302026-09-30111.00323.1021, -16.1682
ZTF ZTF26abydngq Solar System MPC17.96 r—17.962026-09-302026-09-30111.00322.6980, -16.5292
ZTF ZTF26abydngr Solar System MPC18.60 r—18.602026-09-302026-09-30111.00323.1056, -16.6847
ZTF ZTF26abydngs Solar System MPC18.71 r—18.712026-09-302026-09-30111.00322.9064, -16.3830
ZTF ZTF26abydnhj Solar System MPC18.09 r—18.092026-09-302026-09-30111.00324.9127, -19.1089
ZTF ZTF26abydnhk Solar System MPC18.62 r—18.622026-09-302026-09-30111.00324.6671, -19.2486