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
237
in 3 bands (zg, zi, zr)
Nights observed
80
3.0 exposures per night
Baseline
337 d
Jan 21, 2022 – Dec 24, 2022
Open-shutter time
2.0 h
summed exposure time
Median depth
20.94 mag
limiting magnitude per exposure
Median airmass
1.15
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, 2022 – Dec 31, 2022; the from and to in the address take any date, not just the whole years the chips offer.

Jan 1, 2022Mar 25, 2022Jun 17, 2022Sep 8, 2022Dec 1, 2022680Jan 2022 — 2 exposures (zg 1, zr 1)Feb 2022 — 20 exposures (zg 6, zi 2, zr 12)Mar 2022 — 12 exposures (zg 6, zi 1, zr 5)Apr 2022 — 62 exposures (zg 27, zi 7, zr 28)May 2022 — 68 exposures (zg 22, zi 3, zr 43)Jun 2022 — 37 exposures (zg 15, zi 6, zr 16)Jul 2022 — 1 exposure (zi)Oct 2022 — 5 exposures (zr)Nov 2022 — 14 exposures (zr)Dec 2022 — 16 exposures (zg 5, zi 2, zr 9)

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, 2022Mar 25, 2022Jun 17, 2022Sep 8, 2022Dec 1, 2022991754Jan 2022 — 2 added, 756 totalFeb 2022 — 20 added, 776 totalMar 2022 — 12 added, 788 totalApr 2022 — 62 added, 850 totalMay 2022 — 68 added, 918 totalJun 2022 — 37 added, 955 totalJul 2022 — 1 added, 956 totalOct 2022 — 5 added, 961 totalNov 2022 — 14 added, 975 totalDec 2022 — 16 added, 991 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 — 133 exposures (56% of 237) · Show only zrzg — 82 exposures (35% of 237) · Show only zgzi — 22 exposures (9% of 237) · Show only zi237exposureszr — 133 exposures (56% of 237) · Show only zrzr13356%zg — 82 exposures (35% of 237) · Show only zgzg8235%zi — 22 exposures (9% of 237) · Show only zizi229%

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
20
from 411 linked detections
Typical curve length
5 points
median over those objects
Typical revisit
24 h
median gap between consecutive points
Longest baseline
337 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 — 98 gaps (25%)under 1 hour981–6 hours — 37 gaps (9%)1–6 hours376–24 hours — 64 gaps (16%)6–24 hours641–3 days — 74 gaps (19%)1–3 days743–10 days — 58 gaps (15%)3–10 days5810–30 days — 38 gaps (10%)10–30 days381–3 months — 11 gaps (3%)1–3 months113–12 months — 11 gaps (3%)3–12 months11over 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 (117 points).

1 point — 2 objects (10%) · list them1 point22–4 — 7 objects (35%) · list them2–475–9 — 3 objects (15%) · list them5–9310–24 — 4 objects (20%) · list them10–24425–49 — 1 object (5%) · list it25–49150–99 — 2 objects (10%) · list them50–992100 or more — 1 object (5%) · list it100 or more1

Same data as JSON: /api/statistics?from=2022-01-01&to=2022-12-31