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

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).
ASAS-SN: the All-Sky Automated Survey for Supernovae's list of transients: its discoveries, mostly CV candidates, with the magnitudes it quotes
The All-Sky Automated Survey for Supernovae (ASAS-SN); Shappee et al. 2014, ApJ 788, 48; Kochanek et al. 2017, PASP 129, 104502.
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: observers' V photometry of bright novae and CVs (a median a night), observing campaigns that ask for observations, and VSX's names
We acknowledge with thanks the variable star observations from the AAVSO International Database contributed by observers worldwide and used in this research, the AAVSO's observing campaigns, 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
4,901–4,950 of 221,828 · All objects seen in the 7 nights
ObjectClassLast magRisePeakFirst seenLast seenNightsDetectionsRel.RA, DecPartner
ZTF ZTF18abutrei Unknownfaded g−0.419.182018-05-212026-10-0140511.00296.8640, -14.6927Rubin
ZTF ZTF18abutrfq Unknown18.12 g+0.115.862018-05-212026-10-01981441.00295.1668, -14.8264
ZTF ZTF18abutrid Unknownfaded g−0.116.422018-09-102026-10-0133401.00294.3790, -14.5055
ZTF ZTF18abvorrs Unknownfaded g−0.115.482018-05-242026-10-0147621.00298.2248, -19.1356
ZTF ZTF18abvorrx Unknown16.71 g+0.816.142018-05-242026-10-011011591.00298.3033, -19.3187Rubin
ZTF ZTF18abvorrz Unknown18.36 g+0.216.582018-05-212026-10-0172901.00298.7634, -19.5803
ZTF ZTF18abvorsb Unknownfaded g−0.118.382018-05-212026-10-0134391.00298.2104, -19.7316
ZTF ZTF18abvorss Unknown16.46 g+0.816.172018-05-212026-10-011071741.00298.9736, -19.5210
ZTF ZTF18abvortd Unknownfaded g−0.218.512018-05-242026-10-0127351.00299.1185, -19.8186
ZTF ZTF18abvorts Unknown19.10 g+0.218.032018-09-132026-10-0134431.00296.1381, -17.2938
ZTF ZTF18abvortt Unknownfaded g−0.315.422018-09-062026-10-0150541.00300.0798, -17.8130
ZTF ZTF18abvorua Unknown19.08 g+0.117.962018-05-212026-10-0140471.00300.7868, -18.0492
ZTF ZTF18abvoruq Unknownfaded g−0.318.572018-05-242026-10-01821011.00298.4266, -20.3012
ZTF ZTF18abvoruv Unknown18.76 g+0.318.562018-05-242026-10-0134481.00298.8535, -20.1097Rubin
ZTF ZTF18abvoruy Unknown18.87 g+0.217.552018-05-212026-10-01821071.00298.4651, -19.9849
ZTF ZTF18abvorvk Unknown16.21 g+0.314.502018-05-212026-10-01741011.00297.2811, -18.5858
ZTF ZTF18abvorvo Unknown18.05 g+0.217.152018-05-212026-10-0169941.00297.1443, -18.6395
ZTF ZTF18abvorvq Unknownfaded g−0.116.972018-05-242026-10-0136391.00297.1699, -18.2335
ZTF ZTF18abvorvs Unknownfaded g−0.418.002018-05-242026-10-0145581.00297.6573, -18.2970
ZTF ZTF18abvorvz Unknownfaded g−0.117.612018-05-212026-10-0155651.00297.4588, -18.3347
ZTF ZTF18abvorwc Unknownfaded g−0.318.312018-09-132026-10-01931551.00297.1114, -18.5060
ZTF ZTF18abvorwd Unknownfaded g−0.218.232018-05-242026-10-0160731.00297.2708, -18.5995
ZTF ZTF18abvorwz Unknown18.05 g+0.117.092018-05-212026-10-0138431.00298.2635, -17.7223
ZTF ZTF18abvosaw Unknownfaded g−0.217.012018-08-042026-10-011171991.00296.5059, -15.7950
ZTF ZTF18abvosdf Unknownfaded g−0.319.412018-08-042026-10-0113131.00296.1526, -16.1007Rubin
ZTF ZTF18abvosdj Unknown15.33 g+0.314.552018-05-212026-10-01751071.00297.1384, -17.7575
ZTF ZTF18abvosdr Unknown18.41 g+0.217.052018-09-132026-10-01811211.00297.6418, -17.9281
ZTF ZTF18abvosdx Unknownfaded g−0.118.702018-09-132026-10-0124251.00297.4149, -17.8633
ZTF ZTF18abvoseb Unknown19.00 g+0.318.912018-05-212026-10-0132401.00297.3635, -17.6934
ZTF ZTF18abvosew Unknownfaded g−0.218.532018-09-132026-10-0130371.00296.9753, -19.1856
ZTF ZTF18abvosfv Unknownfaded g−0.114.322018-05-212026-10-0157751.00299.7432, -18.3948
ZTF ZTF18abvosfw Unknown16.13 g+0.214.172018-09-132026-10-0132341.00299.4132, -18.4753
ZTF ZTF18abvosfx Unknownfaded g−0.216.832018-05-212026-10-01901351.00299.4957, -18.3144Rubin
ZTF ZTF18abvosgb Unknownfaded g−0.616.702018-05-212026-10-01871231.00299.0509, -18.2259
ZTF ZTF18abvosgj Unknown18.89 g+0.218.512018-08-042026-10-0146521.00299.4620, -18.3597
ZTF ZTF18abvosio Unknownfaded g−0.217.262018-09-132026-10-0148601.00294.7672, -18.1055
ZTF ZTF18abvosjb Unknown18.47 g+0.117.362018-09-132026-10-0121241.00300.2806, -19.3112
ZTF ZTF18abvoska Unknown17.94 g+0.317.902018-09-132026-10-0163751.00296.5384, -20.2396
ZTF ZTF18abvoskd Unknownfaded g−0.317.752018-09-132026-10-0134401.00296.2995, -20.1624Rubin
ZTF ZTF18abvoskh Unknown17.90 g+0.517.902018-05-212026-10-0159821.00296.0248, -19.9918Rubin
ZTF ZTF18abvoskk Unknownfaded g−0.318.982018-05-212026-10-0134351.00296.3337, -20.4605
ZTF ZTF18abvosko Unknownfaded g−0.417.172018-09-132026-10-01881341.00296.1483, -18.4246
ZTF ZTF18abvosks Unknown17.43 g+0.416.832018-05-212026-10-0167961.00296.5709, -18.4640
ZTF ZTF18abvoskx Unknownfaded g−0.218.102018-05-242026-10-0146541.00296.3061, -18.1539
ZTF ZTF18abvosma Unknown17.32 g+0.316.132018-09-132026-10-0144571.00294.8518, -20.4869
ZTF ZTF18abvosnq Unknown18.06 g+0.216.062018-05-242026-10-01951531.00297.1533, -16.8364
ZTF ZTF18abvosnv Unknownfaded g−0.319.122018-05-212026-10-0154611.00297.7053, -16.1111Rubin
ZTF ZTF18abvosqy Unknownfaded g−0.213.422018-05-252026-10-01581041.00301.3945, -20.2869
ZTF ZTF18abvosra Unknownfaded g−0.217.042018-09-132026-10-0143621.00301.7524, -20.1988
ZTF ZTF18abvossa Unknown14.15 g+0.313.782018-09-132026-10-0154641.00295.5813, -16.6376