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.

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.

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 and cutouts
Möller et al. 2021, MNRAS 501, 3272; ZTF (Bellm et al. 2019) and the Vera C. Rubin Observatory LSST.
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.
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.

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
Clear
3,251–3,300 of 214,524 · All objects seen in the 7 nights
ObjectClassLast magRisePeakFirst seenLast seenNightsDetectionsRel.RA, DecPartner
ZTF ZTF17aaaiszy EclBinfaded r−0.418.252017-12-082026-09-2935431.0092.1489, 11.3063
ZTF ZTF17aaaitxy EclBin18.20 r+0.218.202017-12-142026-09-2954711.0094.9334, 9.6098
ZTF ZTF17aaanqet LongPeriodV*faded r−0.215.072017-12-152026-09-2943591.0093.6631, 11.4201
ZTF ZTF17aaanqky EclBin15.67 r+0.214.882017-12-052026-09-2936581.0089.5955, 12.9047
ZTF ZTF17aaanqoq LongPeriodV*faded r−0.115.192017-12-052026-09-2954741.0095.0780, 10.1110
ZTF ZTF17aaanrgo Variable*15.45 r+0.914.162017-12-152026-09-29802481.0095.1589, 8.1451
ZTF ZTF17aaanrgp Unknown17.71 r+2.517.632017-12-152026-09-2928481.0095.4191, 8.1224
ZTF ZTF17aaanxtd delSctV*faded r−0.118.442017-12-152026-09-2931351.0089.6296, 14.7975
ZTF ZTF17aaaojst EclBinfaded r−0.218.142017-12-052026-09-2958971.0096.1019, 8.1125
ZTF ZTF17aaaojtt EclBin18.59 r+0.218.282017-12-142026-09-2957691.0095.0554, 9.4179
ZTF ZTF17aaaojvg delSctV*faded r−0.117.492017-12-152026-09-2932411.0091.7872, 11.4000
ZTF ZTF17aaaojxr LongPeriodV*15.91 r+0.415.912017-12-142026-09-2925351.0092.1601, 13.0810
ZTF ZTF17aaaokam LongPeriodV*faded r−0.613.952017-12-152026-09-2943641.0091.4328, 8.6062
ZTF ZTF17aaaokrd EclBinfaded r−0.318.132017-12-082026-09-2949601.0090.4492, 11.8688
ZTF ZTF17aaaoxwu EclBinfaded r−0.217.082017-12-082026-09-2924271.0092.1137, 13.2340
ZTF ZTF17aaapenx EclBin18.05 r+0.116.452017-12-052026-09-2955731.0095.3077, 10.4128
ZTF ZTF17aaapenz EclBin18.10 r+0.118.102017-12-152026-09-2925281.0091.8554, 11.1188
ZTF ZTF17aaapepf EclBinfaded r−0.517.922017-12-142026-09-2964891.0095.7497, 10.1070
ZTF ZTF17aaarwqm LongPeriodV*faded r−0.113.922017-10-152026-09-29531221.0090.7451, 15.3425
ZTF ZTF17aaarzzs RSCVnV*faded r−0.114.902017-12-052026-09-2943891.0093.8565, 8.1981
ZTF ZTF17aaatjaj ClassicalCepfaded r−0.215.802017-12-052026-09-29601251.0095.1678, 8.1495
ZTF ZTF17aaauaqq EclBinfaded r−0.516.092017-12-052026-09-2958831.0094.3108, 10.8134
ZTF ZTF17aaaucin EclBin18.83 r+0.117.702017-12-052026-09-2965971.0094.5948, 10.2683
ZTF ZTF17aaawbik Unknownfaded r−0.117.132017-11-162026-09-29752071.0089.2815, 15.3007
ZTF ZTF17aaawbvn Unknown18.32 r+0.118.102017-11-212026-09-29511211.0089.3132, 15.3223
ZTF ZTF17aabdkao EclBinfaded r−0.117.592017-12-142026-09-2924291.0090.0198, 12.4973
ZTF ZTF17aabfntz EclBinfaded r−0.216.282017-12-052026-09-2929351.0089.8657, 14.8322
ZTF ZTF17aabfowg Starfaded r−0.117.572017-12-052026-09-2916191.0089.4307, 12.5679
ZTF ZTF17aabfpnq EclBinfaded r−0.417.472017-12-052026-09-2924291.0089.5517, 12.8285
ZTF ZTF17aabgimu alf2CVnV*16.63 r+0.116.122017-12-172026-09-2910150.9989.7821, 14.0002
ZTF ZTF17aabgiok EclBin15.61 r+0.215.612017-12-172026-09-2911131.0089.7983, 14.2171
ZTF ZTF17aabgmsd EclBinfaded r−0.217.622017-12-072026-09-2959761.0092.7972, 11.4796
ZTF ZTF17aabgmvj TTauri*18.39 r+0.117.182017-12-082026-09-2947641.0092.3357, 13.4036
ZTF ZTF17aabhjdj EclBinfaded r−0.418.192017-12-052026-09-29681241.0089.2179, 14.6852
ZTF ZTF17aablkhp EclBinfaded r−0.318.602017-12-142026-09-2947591.0095.2386, 8.4884
ZTF ZTF17aablntj RSCVnV*faded r−0.118.572017-12-152026-09-2920271.0095.5578, 10.9073
ZTF ZTF17aablnwe YSOfaded r−0.1—2017-12-172026-09-29450.9792.1309, 13.9205
ZTF ZTF17aablrxo Unknown17.94 r+0.217.762017-12-172026-09-29691111.0094.3431, 10.2444
ZTF ZTF17aabmedg Unknown15.13 r+0.214.592017-12-052026-09-2936491.0090.3138, 13.8159
ZTF ZTF17aabmjua Mirafaded r−3.315.542017-12-172026-09-2927371.0091.6794, 9.9420
ZTF ZTF17aabmkby Unknownfaded r−0.119.252017-12-172026-09-2915191.0092.0515, 9.9667
ZTF ZTF17aabmrvy BYDraV*faded r−0.118.222017-12-172026-09-2913171.0089.3874, 10.0380
ZTF ZTF17aabmrwq EclBinfaded r−0.217.232017-12-082026-09-2913231.0088.9812, 10.0582
ZTF ZTF17aabmvuk LongPeriodV*faded r−0.115.312017-12-172026-09-29661.0090.2993, 12.9021
ZTF ZTF17aabnanh EclBinfaded r−0.615.942017-12-052026-09-2934431.0094.3143, 10.8632
ZTF ZTF17aabnjpi Unknown16.86 r+0.116.342017-12-172026-09-29661261.0091.3539, 11.9928
ZTF ZTF17aabnlaz Unknown16.03 r+0.115.652017-12-172026-09-29761761.0089.0682, 12.8730
ZTF ZTF17aabnpji EclBinfaded r−0.116.362017-12-052026-09-2951951.0089.1803, 12.2849
ZTF ZTF17aabonur EclBinfaded r−0.117.102017-12-052026-09-2935381.0095.7390, 10.5658
ZTF ZTF17aabpfgp alf2CVnV*15.60 r+0.115.162017-12-052026-09-2927310.9989.1801, 11.3599