VWDB Višnjan–Washington Sky Survey
Stand-in data
STAND-IN DATA. This catalog contains 2,279 ZTF detections and 1,000,000 synthetic fixture rows — NOT Visnjan-Washington observations. Stand-in data is loaded while the VW Data Analysis Pipeline is built. Do not use these measurements for science.

Statistics

The survey's observing record, computed from survey.exposures. These are ZTF's observing statistics, not Visnjan-Washington's — the stand-in notice above applies to every plot here as much as it does to a search result, and the synthetic fixture is excluded by default because its cadence is invented (a perfectly uniform one exposure every 0.01 day), not observed.

Clump by day week month Dates all 2018 2019 2020 2021 2022 2023 2024 2025 Band zg zi zr all Synthetic fixture excluded
Exposures
666
in 1 band (zr)
Nights observed
397
1.7 exposures per night
Baseline
7.2 yr
Apr 9, 2018 – Jun 27, 2025
Open-shutter time
5.7 h
summed exposure time
Median depth
20.93 mag
limiting magnitude per exposure
Median airmass
1.13
secant of the zenith angle

Exposures per month

How often the survey observed, split by band. A gap is a month it didn't run, not one with nothing to see. Hover a column for its date, its total and how that total divides between bands, or click a band in the legend to drop it from the chart.

Apr 1, 2018Jan 15, 2020Oct 31, 2021Aug 16, 2023Jun 1, 2025480Show zgzgShow ziziShow all bandszrApr 2018 — 19 exposures (zr)May 2018 — 15 exposures (zr)Jun 2018 — 15 exposures (zr)Nov 2018 — 4 exposures (zr)Dec 2018 — 11 exposures (zr)Jan 2019 — 13 exposures (zr)Feb 2019 — 7 exposures (zr)Mar 2019 — 13 exposures (zr)Apr 2019 — 19 exposures (zr)May 2019 — 7 exposures (zr)Jun 2019 — 8 exposures (zr)Jul 2019 — 3 exposures (zr)Nov 2019 — 15 exposures (zr)Dec 2019 — 2 exposures (zr)Jan 2020 — 4 exposures (zr)Feb 2020 — 20 exposures (zr)Mar 2020 — 9 exposures (zr)Apr 2020 — 21 exposures (zr)May 2020 — 13 exposures (zr)Jun 2020 — 3 exposures (zr)Jul 2020 — 1 exposure (zr)Nov 2020 — 18 exposures (zr)Dec 2020 — 9 exposures (zr)Jan 2021 — 6 exposures (zr)Feb 2021 — 11 exposures (zr)Mar 2021 — 20 exposures (zr)Apr 2021 — 48 exposures (zr)May 2021 — 40 exposures (zr)Jun 2021 — 18 exposures (zr)Jul 2021 — 3 exposures (zr)Oct 2021 — 8 exposures (zr)Nov 2021 — 12 exposures (zr)Jan 2022 — 1 exposure (zr)Feb 2022 — 12 exposures (zr)Mar 2022 — 5 exposures (zr)Apr 2022 — 28 exposures (zr)May 2022 — 43 exposures (zr)Jun 2022 — 16 exposures (zr)Oct 2022 — 5 exposures (zr)Nov 2022 — 14 exposures (zr)Dec 2022 — 9 exposures (zr)Jan 2023 — 2 exposures (zr)Feb 2023 — 9 exposures (zr)Mar 2023 — 5 exposures (zr)Apr 2023 — 27 exposures (zr)May 2023 — 10 exposures (zr)Jun 2023 — 9 exposures (zr)Aug 2023 — 2 exposures (zr)Nov 2023 — 12 exposures (zr)Dec 2023 — 2 exposures (zr)Jan 2024 — 15 exposures (zr)Feb 2024 — 9 exposures (zr)Mar 2024 — 3 exposures (zr)Apr 2024 — 5 exposures (zr)May 2024 — 2 exposures (zr)May 2025 — 2 exposures (zr)Jun 2025 — 4 exposures (zr)

Cumulative exposures

The same data, accumulated — flat stretches are when the survey was not running, which the bar chart above makes easy to miss among the months that did have data. Hover a point for the running total and what it added.

Apr 1, 2018Jan 15, 2020Oct 31, 2021Aug 16, 2023Jun 1, 20256660Apr 2018 — 19 added, 19 totalMay 2018 — 15 added, 34 totalJun 2018 — 15 added, 49 totalNov 2018 — 4 added, 53 totalDec 2018 — 11 added, 64 totalJan 2019 — 13 added, 77 totalFeb 2019 — 7 added, 84 totalMar 2019 — 13 added, 97 totalApr 2019 — 19 added, 116 totalMay 2019 — 7 added, 123 totalJun 2019 — 8 added, 131 totalJul 2019 — 3 added, 134 totalNov 2019 — 15 added, 149 totalDec 2019 — 2 added, 151 totalJan 2020 — 4 added, 155 totalFeb 2020 — 20 added, 175 totalMar 2020 — 9 added, 184 totalApr 2020 — 21 added, 205 totalMay 2020 — 13 added, 218 totalJun 2020 — 3 added, 221 totalJul 2020 — 1 added, 222 totalNov 2020 — 18 added, 240 totalDec 2020 — 9 added, 249 totalJan 2021 — 6 added, 255 totalFeb 2021 — 11 added, 266 totalMar 2021 — 20 added, 286 totalApr 2021 — 48 added, 334 totalMay 2021 — 40 added, 374 totalJun 2021 — 18 added, 392 totalJul 2021 — 3 added, 395 totalOct 2021 — 8 added, 403 totalNov 2021 — 12 added, 415 totalJan 2022 — 1 added, 416 totalFeb 2022 — 12 added, 428 totalMar 2022 — 5 added, 433 totalApr 2022 — 28 added, 461 totalMay 2022 — 43 added, 504 totalJun 2022 — 16 added, 520 totalOct 2022 — 5 added, 525 totalNov 2022 — 14 added, 539 totalDec 2022 — 9 added, 548 totalJan 2023 — 2 added, 550 totalFeb 2023 — 9 added, 559 totalMar 2023 — 5 added, 564 totalApr 2023 — 27 added, 591 totalMay 2023 — 10 added, 601 totalJun 2023 — 9 added, 610 totalAug 2023 — 2 added, 612 totalNov 2023 — 12 added, 624 totalDec 2023 — 2 added, 626 totalJan 2024 — 15 added, 641 totalFeb 2024 — 9 added, 650 totalMar 2024 — 3 added, 653 totalApr 2024 — 5 added, 658 totalMay 2024 — 2 added, 660 totalMay 2025 — 2 added, 662 totalJun 2025 — 4 added, 666 total

Exposures by filter

How the observing above divides between bands — always the whole split, whichever band is currently picked. Click a slice to show only that band in the charts above, or click the one already picked to come back to all of them.

zr — 666 exposures (50% of 1,339) · Show all bandszg — 567 exposures (42% of 1,339) · Show zgzi — 106 exposures (8% of 1,339) · Show zi1,339exposureszr — 666 exposures (50% of 1,339) · Show all bandszr66650%zg — 567 exposures (42% of 1,339) · Show zgzg56742%zi — 106 exposures (8% of 1,339) · Show zizi1068%

Revisits and light-curve length

How often the survey comes back to the same object, over the same bands and dates as the charts above. Grouped by ZTF's own association of the stand-in data (ztf_oid), which is the only thing linking one detection to another until phase 2 builds objects — so these describe what the stand-in catalog can support, not a VW data product. Only the 2,279 detections ZTF associated this way are counted, out of 1,002,279 sources in the catalog: a source with no association has no object identity here at all, so it is absent from these charts rather than appearing as a one-point curve. With a band picked, a gap is the time to the next detection in that band — which is the interval that matters when you fold a light curve.

Objects with a curve
14
from 1,414 linked detections
Typical curve length
19 points
median over those objects
Typical revisit
1.1 d
median gap between consecutive points
Longest baseline
7.2 yr
first to last point on one object

Time between consecutive detections

The sampling, which is what sets the periods a light curve can recover: a signal shorter than the typical gap is not resolved, and one near a spike in this histogram aliases against it. Log-spaced buckets — revisits run from minutes to years. Hover a row for its share.

under 1 hour — 335 gaps (24%)under 1 hour3351–6 hours — 72 gaps (5%)1–6 hours726–24 hours — 205 gaps (15%)6–24 hours2051–3 days — 309 gaps (22%)1–3 days3093–10 days — 220 gaps (16%)3–10 days22010–30 days — 140 gaps (10%)10–30 days1401–3 months — 42 gaps (3%)1–3 months423–12 months — 62 gaps (4%)3–12 months62over a year — 15 gaps (1%)over a year15

Detections per object

How long the curves are. An object with a handful of points has a position and little else — fitting a period or an orbit takes tens of points at least, so it is the bottom rows here that are worth plotting. Plot the best-sampled one (590 points).

1 point — 0 objects (0%)1 point02–4 — 1 object (7%) · list it2–415–9 — 2 objects (14%) · list them5–9210–24 — 5 objects (36%) · list them10–24525–49 — 2 objects (14%) · list them25–49250–99 — 1 object (7%) · list it50–991100 or more — 3 objects (21%) · list them100 or more3

Same data as JSON: /api/statistics?band=zr