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 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).
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
4,751–4,800 of 212,894 · All objects seen in the 7 nights
ObjectClassLast magRisePeakFirst seenLast seenNightsDetectionsRel.RA, DecPartner
ZTF ZTF18acaphnd LongPeriodV*faded r−0.416.112018-05-282026-09-301181621.00295.0417, 5.3571
ZTF ZTF18acbwing RSCVnV*faded r−0.118.092018-11-012026-09-3037411.00297.3611, 1.7582
ZTF ZTF18acbwiqz Unknownfaded r−0.118.982018-07-112026-09-3015191.00295.3242, 3.3367
ZTF ZTF18acbwirz Variable*17.56 r+0.217.212018-07-112026-09-301181741.00294.3689, 2.0069
ZTF ZTF18acbwisa Unknown18.08 r+0.117.532018-08-182026-09-30981211.00294.7330, 2.3865
ZTF ZTF18acbwisb EclBinfaded r−0.1—2018-06-042026-09-3016181.00294.5720, 1.8932
ZTF ZTF18acbwiuh Unknownfaded r−0.118.452018-06-282026-09-30811081.00294.5732, 1.2882
ZTF ZTF18acbwjim Unknownfaded r−0.117.192018-07-202026-09-3011131.00293.9588, 1.2864
ZTF ZTF18accnzcd Variable*faded r−0.116.002018-06-282026-09-3033360.75296.4385, 2.9929
ZTF ZTF18accoafk EclBinfaded r−0.116.032018-05-282026-09-3076951.00294.9956, 1.6660
ZTF ZTF18accoajx Unknown17.28 r+0.116.952018-11-042026-09-30551.00298.7606, 2.3704
ZTF ZTF18accogki Unknownfaded r−0.317.082018-06-042026-09-301131611.00292.3876, 7.9473
ZTF ZTF18accojjj EclBinfaded r−0.517.312018-06-112026-09-301472301.00294.9596, 5.6394
ZTF ZTF18accpmok EclBinfaded r−0.718.852018-05-202026-09-3015161.00298.3827, 2.5224
ZTF ZTF18accpncg Unknownfaded r−0.215.782018-06-082026-09-301261781.00294.7997, 5.6967
ZTF ZTF18aceglbk EclBin18.36 r+0.117.822018-11-072026-09-3069831.00298.1702, 2.5305
ZTF ZTF18acehqli Unknownfaded r−0.1—2018-11-072026-09-3040531.00296.0338, 2.5320
ZTF ZTF18acehqne RSCVnV*faded r−0.116.662018-05-202026-09-30891071.00296.5167, 2.3417
ZTF ZTF18acehqni Unknownfaded r−0.219.092018-11-072026-09-3063811.00293.3536, 1.5097
ZTF ZTF18acehqol Unknownfaded r−0.2—2018-08-242026-09-3049531.00294.9051, 3.1784
ZTF ZTF18acehqom Unknown17.76 r+0.217.652018-05-202026-09-30771041.00294.7990, 3.5900
ZTF ZTF18acehrey Unknownfaded r−0.117.992018-05-282026-09-3022251.00293.9396, 5.8864
ZTF ZTF18acehrfs Unknown16.90 r+0.316.902018-11-072026-09-301131631.00293.6155, 5.4948
ZTF ZTF18acgxezm EclBinfaded r−0.214.742018-05-202026-09-3033410.99296.1309, 0.9931
ZTF ZTF18acgxfag Unknownfaded r−0.318.552018-11-102026-09-3022281.00296.5478, 1.3277
ZTF ZTF18acgxfhy Unknown18.02 r+0.118.022018-09-142026-09-30110.99295.3077, 1.2714
ZTF ZTF18acgxfif Unknown18.02 r+0.317.972018-07-202026-09-301502171.00295.4935, 1.2388
ZTF ZTF18acgxfrn LongPeriodV*faded r−0.116.882018-05-232026-09-3074981.00296.5018, 2.3876
ZTF ZTF18acgxgnc LongPeriodV*_Candidate18.71 r+0.117.522018-07-202026-09-3067871.00294.0647, 1.9902
ZTF ZTF18acgxhbf Unknown16.77 r+0.116.772018-06-042026-09-30671.00294.7783, 2.9320
ZTF ZTF18acgxhss LongPeriodV*_Candidate18.05 r+0.117.402018-06-282026-09-3049551.00294.6652, 4.9828
ZTF ZTF18acgxiyy LongPeriodV*15.32 r+0.215.232018-05-282026-09-3062891.00294.6547, 6.2901
ZTF ZTF18acgxjqd EclBinfaded r−0.1—2018-08-102026-09-30660.99293.5536, 6.2031
ZTF ZTF18acgxjqn Unknownfaded r−0.1—2018-08-022026-09-3011151.00293.6733, 5.6721
ZTF ZTF18acgxkdh LongPeriodV*_Candidate17.00 r+0.116.792018-06-282026-09-3024291.00291.9216, 6.3087
ZTF ZTF18acgxopp Unknown16.08 r+0.115.622018-06-142026-09-30661.00292.6646, 5.2509
ZTF ZTF18achafhw Unknownfaded r−0.218.262018-11-102026-09-3046511.00294.4094, 2.9506
ZTF ZTF18achafwd EclBin16.78 r+0.116.782018-05-282026-09-30330.94294.1604, 6.0976
ZTF ZTF18acjghdn LongPeriodV*faded r−0.116.542018-05-202026-09-30341.00296.4671, 3.3124
ZTF ZTF18acjghgr LongPeriodV*faded r−0.214.162018-06-042026-09-30911211.00296.1251, 3.2219
ZTF ZTF18actwsmi LongPeriodV*faded r−0.316.472018-05-282026-09-3016161.00293.5347, 2.2163
ZTF ZTF18actwsth LongPeriodV*_Candidatefaded r−0.116.652018-07-072026-09-30221.00294.2818, 5.4699
ZTF ZTF18actwtas LongPeriodV*15.72 r+0.114.652018-06-042026-09-3035381.00296.3141, 3.4242
ZTF ZTF18acufyrn EclBinfaded r−0.219.352018-06-132026-09-3019191.00295.6742, 3.5866
ZTF ZTF18acufzal Unknownfaded r−0.1—2018-06-282026-09-30811151.00293.6516, 5.4996
ZTF ZTF18acufzit Unknown18.13 r+0.217.912018-12-092026-09-301472091.00293.6175, 5.8425
ZTF ZTF18acugcad Unknown18.49 r+0.218.492018-12-092026-09-3027281.00294.5900, 6.0034
ZTF ZTF18acugcez Unknownfaded r−0.217.832018-11-042026-09-301291671.00293.5257, 5.0246
ZTF ZTF18acugekr LongPeriodV*16.47 r+0.316.472018-06-042026-09-3047641.00291.5972, 6.1541
ZTF ZTF18acuggel Unknown17.81 r+0.217.672018-06-112026-09-301021441.00293.6687, 4.8091