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 Synthetic fixture excluded
Exposures
309
in 3 bands (zg, zi, zr)
Nights observed
107
2.9 exposures per night
Baseline
315 d
Jan 2, 2021 – Nov 13, 2021
Open-shutter time
2.6 h
summed exposure time
Median depth
21.21 mag
limiting magnitude per exposure
Median airmass
1.12
secant of the zenith angle

Exposures per month

How often the survey observed. 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. Zoomed to Jan 1, 2021 – Dec 31, 2021; the from and to in the address take any date, not just the whole years the chips offer.

Jan 1, 2021Mar 18, 2021Jun 2, 2021Aug 17, 2021Nov 1, 2021860Jan 2021 — 13 exposures (zg 3, zi 4, zr 6)Feb 2021 — 25 exposures (zg 8, zi 6, zr 11)Mar 2021 — 38 exposures (zg 14, zi 4, zr 20)Apr 2021 — 86 exposures (zg 33, zi 5, zr 48)May 2021 — 84 exposures (zg 38, zi 6, zr 40)Jun 2021 — 37 exposures (zg 14, zi 5, zr 18)Jul 2021 — 5 exposures (zg 1, zi 1, zr 3)Oct 2021 — 8 exposures (zr)Nov 2021 — 13 exposures (zi 1, zr 12)

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.

Jan 1, 2021Mar 18, 2021Jun 2, 2021Aug 17, 2021Nov 1, 2021754445Jan 2021 — 13 added, 458 totalFeb 2021 — 25 added, 483 totalMar 2021 — 38 added, 521 totalApr 2021 — 86 added, 607 totalMay 2021 — 84 added, 691 totalJun 2021 — 37 added, 728 totalJul 2021 — 5 added, 733 totalOct 2021 — 8 added, 741 totalNov 2021 — 13 added, 754 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.

zr — 166 exposures (54% of 309) · Show only zrzg — 111 exposures (36% of 309) · Show only zgzi — 32 exposures (10% of 309) · Show only zi309exposureszr — 166 exposures (54% of 309) · Show only zrzr16654%zg — 111 exposures (36% of 309) · Show only zgzg11136%zi — 32 exposures (10% of 309) · Show only zizi3210%

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.

Objects with a curve
23
from 592 linked detections
Typical curve length
9 points
median over those objects
Typical revisit
1 d
median gap between consecutive points
Longest baseline
315 d
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 — 130 gaps (23%)under 1 hour1301–6 hours — 48 gaps (8%)1–6 hours486–24 hours — 90 gaps (16%)6–24 hours901–3 days — 136 gaps (24%)1–3 days1363–10 days — 100 gaps (18%)3–10 days10010–30 days — 53 gaps (9%)10–30 days531–3 months — 4 gaps (1%)1–3 months43–12 months — 8 gaps (1%)3–12 months8over a year — 0 gaps (0%)over a year0

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 (148 points).

1 point — 5 objects (22%) · list them1 point52–4 — 4 objects (17%) · list them2–445–9 — 3 objects (13%) · list them5–9310–24 — 4 objects (17%) · list them10–24425–49 — 3 objects (13%) · list them25–49350–99 — 1 object (4%) · list it50–991100 or more — 3 objects (13%) · list them100 or more3

Same data as JSON: /api/statistics?from=2021-01-01&to=2021-12-31