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. A nova or CV brighter than 14 also gets AAVSO's observers' V for two months: the median of a sample of each night's observations (the tooltip says of how many). 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.
  • ASAS-SN: discoveries on the All-Sky Automated Survey for Supernovae's list of transients that nothing above has, mostly cataclysmic variables in outburst (ASASSN-26fg). Each detection is a magnitude the list quotes, in g. An object that matches one shows its ASAS-SN name.
  • 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, CBAT or ASAS-SN object neither ATLAS nor AAVSO measures (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, CBAT or ASAS-SN object gets only ATLAS's photometry while it is brighter than 19, and AAVSO's nightly V if it is a nova or CV brighter than 14. 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 Galactic novae, TNS for supernovae and novae in nearby galaxies, CBAT for an unconfirmed TOCP entry; an AGN only to AAVSO when VSX lists it, and to TNS when it flares), 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

See Data Sources.

Everything here is also available via a JSON API.

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.

Contact us

Objects

Objects
Source
Bucket
More filters
Clear
3,451–3,500 of 221,842 · All objects seen in the 7 nights
Subscribe

A feed of this view: an item for each object that matches, newest discovery first, so a reader shows new matches as they come. Give the view a name under More filters to title it.

The same view as JSON, for scripts (the API; 100 rows a page, with offset):

Its first 100 objects as targets for a TOM Toolkit TOM (Targets → Import Targets), with every name and a link back:

RSSTOM targets (CSV)
ObjectClassLast magRisePeakFirst seenLast seenNightsDetectionsRel.RA, DecPartner
ZTF ZTF18abusrln Unknown16.61 g+0.215.582018-09-102026-10-0167781.00288.3173, -20.2180
ZTF ZTF18abusrlp Unknownfaded g−0.515.442018-05-242026-10-01741111.00287.9537, -20.3908
ZTF ZTF18abusrlw Unknown17.28 g+0.215.402018-05-242026-10-0153821.00288.4219, -20.3105
ZTF ZTF18abusrlz Unknownfaded g−0.117.032018-09-102026-10-0140481.00288.5894, -20.2561Rubin
ZTF ZTF18abusrmb Unknownfaded g−1.512.022018-05-242026-10-01861281.00288.1196, -20.0941
ZTF ZTF18abusrme Unknownfaded g−0.217.802018-05-242026-10-0156701.00288.7379, -20.0928Rubin
ZTF ZTF18abusrmf Unknownfaded g−0.416.792018-05-242026-10-01721091.00288.3958, -19.9355Rubin
ZTF ZTF18abusrmk Unknown17.60 g+0.616.552018-08-012026-10-0162751.00287.9205, -19.9346Rubin
ZTF ZTF18abusrmm Unknown17.95 g+0.217.032018-05-242026-10-0155651.00288.6327, -19.9625Rubin
ZTF ZTF18abusrnh Unknownfaded g−0.314.442018-08-012026-10-0139621.00289.0326, -18.0968
ZTF ZTF18abusrnk Unknown17.29 g+0.216.792018-05-242026-10-01761091.00289.7763, -18.2615Rubin
ZTF ZTF18abusrnm Unknown16.11 g+0.214.192018-08-012026-10-01671351.00289.1631, -18.5066
ZTF ZTF18abusrnn Unknownfaded g−0.516.852018-05-242026-10-01831361.00289.5177, -18.6123Rubin
ZTF ZTF18abusrnp Unknown17.34 g+0.216.972018-08-012026-10-0161811.00289.4110, -18.0556Rubin
ZTF ZTF18abusrnr Unknownfaded g−0.217.702018-09-102026-10-0117191.00289.1629, -18.5521
ZTF ZTF18abusrnx Unknownfaded g−0.217.822018-05-242026-10-0163751.00289.5179, -18.5520Rubin
ZTF ZTF18abusroc Unknownfaded g−0.217.382018-09-102026-10-01811031.00289.6760, -18.7844Rubin
ZTF ZTF18abusrod Unknownfaded g−0.219.302018-09-102026-10-0121211.00289.8159, -18.3638Rubin
ZTF ZTF18abusroi Unknown18.05 g+0.417.572018-09-102026-10-01931601.00289.2401, -18.7077Rubin
ZTF ZTF18abusrom Unknownfaded g−0.418.602018-08-012026-10-0115221.00288.9669, -18.4333Rubin
ZTF ZTF18abusroy Unknown16.30 g+0.115.522018-05-242026-10-0132421.00289.4750, -13.6500
ZTF ZTF18abusrpa Unknownfaded g−0.515.472018-05-242026-10-0146571.00289.4445, -14.0991
ZTF ZTF18abusrpo Unknownfaded g−0.217.392018-09-102026-10-01961521.00289.5833, -14.0568
ZTF ZTF18abusrpq Unknownfaded g−0.316.582018-08-012026-10-0162941.00289.0965, -13.8724
ZTF ZTF18abusrpu Unknownfaded g−0.217.742018-09-102026-10-011021611.00289.5375, -13.5772
ZTF ZTF18abusrre Unknownfaded g−0.215.312018-09-072026-10-011111951.00288.1563, -13.5760
ZTF ZTF18abusrrh Unknownfaded g−0.218.302018-09-042026-10-0125271.00288.1066, -13.8113
ZTF ZTF18abusrrj Unknownfaded g−0.517.042018-09-102026-10-011001071.00288.4054, -14.1293
ZTF ZTF18abusrrv Unknownfaded g−0.611.922018-08-012026-10-0163691.00288.6360, -18.8120
ZTF ZTF18abusrrx Unknown14.60 g+0.314.452018-09-102026-10-0135361.00288.6112, -18.8243
ZTF ZTF18abusrrz Unknownfaded g−0.713.962018-05-242026-10-0156580.67288.3914, -18.1283
ZTF ZTF18abusrsf Unknown15.07 g+0.912.862018-05-242026-10-01801171.00288.0658, -18.4923
ZTF ZTF18abusrsu Unknown18.12 g+0.216.232018-09-102026-10-0145651.00288.4959, -18.8222Rubin
ZTF ZTF18abusrta Unknownfaded g−0.417.302018-05-242026-10-01781211.00288.2625, -18.4854Rubin
ZTF ZTF18abusrtd UnknownAT 2020aaknfaded g−0.617.882018-05-242026-10-01891491.00288.6088, -18.5930
ZTF ZTF18abusrth Unknownfaded g−0.2—2018-09-102026-10-0134491.00288.6466, -18.1297
ZTF ZTF18abusrue Unknown14.64 g+0.814.572018-05-242026-10-01991481.00289.8861, -16.7122
ZTF ZTF18abusrui Unknown15.91 g+0.215.462018-09-102026-10-0132331.00290.2853, -16.7913
ZTF ZTF18abusruk Unknownfaded g−0.317.972018-05-242026-10-0141651.00290.4224, -16.3603
ZTF ZTF18abusrum Unknown17.49 g+0.316.792018-05-242026-10-011051671.00289.9406, -16.4706
ZTF ZTF18abusruo Unknown18.74 g+0.116.692018-05-242026-10-01771011.00290.3394, -16.6777
ZTF ZTF18abusruq Unknownfaded g−0.217.432018-08-012026-10-01961371.00290.2982, -16.1481
ZTF ZTF18abusruu Unknown17.83 g+0.517.032018-05-242026-10-011101621.00290.0763, -16.6267
ZTF ZTF18abusrvf Unknownfaded g−0.318.702018-05-242026-10-0164811.00290.3197, -16.5111
ZTF ZTF18abusrvh Unknownfaded g−0.417.632018-08-012026-10-0181921.00290.6506, -16.7982
ZTF ZTF18abusrvo Unknown17.33 g+0.216.352018-05-242026-10-01881101.00289.1034, -15.8096
ZTF ZTF18abusrvp Unknown16.27 g+0.616.272018-05-242026-10-01841151.00289.4791, -15.8755
ZTF ZTF18abusrvq Unknownfaded g−0.216.162018-05-242026-10-01831261.00289.0906, -15.6600
ZTF ZTF18abusrvr Unknownfaded g−0.214.912018-05-242026-10-01861471.00289.2675, -15.8118
ZTF ZTF18abusrwz Unknownfaded g—13.092018-05-242026-10-011081541.00289.5989, -16.1542