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
175
in 3 bands (zg, zi, zr)
Nights observed
79
2.2 exposures per night
Baseline
354 d
Jan 2, 2020 – Dec 21, 2020
Open-shutter time
1.5 h
summed exposure time
Median depth
21.21 mag
limiting magnitude per exposure
Median airmass
1.11
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, 2020 – Dec 31, 2020; the from and to in the address take any date, not just the whole years the chips offer.

Jan 1, 2020Mar 24, 2020Jun 16, 2020Sep 8, 2020Dec 1, 2020400Jan 2020 — 9 exposures (zg 5, zr 4)Feb 2020 — 35 exposures (zg 15, zr 20)Mar 2020 — 15 exposures (zg 6, zr 9)Apr 2020 — 40 exposures (zg 18, zi 1, zr 21)May 2020 — 30 exposures (zg 17, zr 13)Jun 2020 — 7 exposures (zg 4, zr 3)Jul 2020 — 1 exposure (zr)Nov 2020 — 20 exposures (zg 2, zr 18)Dec 2020 — 18 exposures (zg 7, 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, 2020Mar 24, 2020Jun 16, 2020Sep 8, 2020Dec 1, 2020445270Jan 2020 — 9 added, 279 totalFeb 2020 — 35 added, 314 totalMar 2020 — 15 added, 329 totalApr 2020 — 40 added, 369 totalMay 2020 — 30 added, 399 totalJun 2020 — 7 added, 406 totalJul 2020 — 1 added, 407 totalNov 2020 — 20 added, 427 totalDec 2020 — 18 added, 445 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 — 98 exposures (56% of 175) · Show only zrzg — 74 exposures (42% of 175) · Show only zgzi — 3 exposures (2% of 175) · Show only zi175exposureszr — 98 exposures (56% of 175) · Show only zrzr9856%zg — 74 exposures (42% of 175) · Show only zgzg7442%zi — 3 exposures (2% of 175) · Show only zizi32%

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
17
from 321 linked detections
Typical curve length
5 points
median over those objects
Typical revisit
2 d
median gap between consecutive points
Longest baseline
354 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 — 78 gaps (26%)under 1 hour781–6 hours — 1 gap (0%)1–6 hours16–24 hours — 34 gaps (11%)6–24 hours341–3 days — 73 gaps (24%)1–3 days733–10 days — 79 gaps (26%)3–10 days7910–30 days — 27 gaps (9%)10–30 days271–3 months — 4 gaps (1%)1–3 months43–12 months — 8 gaps (3%)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 (86 points).

1 point — 2 objects (12%) · list them1 point22–4 — 5 objects (29%) · list them2–455–9 — 4 objects (24%) · list them5–9410–24 — 2 objects (12%) · list them10–24225–49 — 1 object (6%) · list it25–49150–99 — 3 objects (18%) · list them50–993100 or more — 0 objects (0%)100 or more0

Same data as JSON: /api/statistics?from=2020-01-01&to=2020-12-31