V3 draft / A

Dark skies by train · Izery, Polana JakuszyckaBuy the return first

Ticket: arrival, night, return

Model example 1 — all nightConventional times — not a timetable and not an ephemeris

Arrival

18:30

Polana Jakuszycka · day of departure

Timetable: Koleje Dolnośląskie (to be checked)

7 h 30 min

of shared night at the observing spot

  • ticket: arrival → return
  • walk
  • buffer before departure
  • stated night
  • shared part
  • +1 = next day

You enter the night hours from a dated ephemeris. This draft names no such source (no material available).

Return

06:15+1

train departure · next day

Timetable: Koleje Dolnośląskie (to be checked)

Entry
19:00
Night
21:00–04:30 +1
Exit
05:25 +1

You can be at the observing spot from 19:00 to 05:25 +1 (after a 30 min walk and with a 20 min buffer before departure). Stated night: 21:00–04:30 +1 (7 h 30 min). Shared part: 21:00–04:30 +1. The whole stated night fits within the stay.

A return at 05:20 +1 or later does not shorten the night; every minute earlier takes away a minute.

The shared interval is only a calculation of clock times. It does not confirm the weather, the Moon, light in the surroundings, visibility of the Milky Way or the safety of the walk.

Change the times, walk, buffer or date
Train and walk
Time from the timetable, entered by you. You change the return on the ticket.
Range 0–180. The same both ways — this is an assumption.
Spare time on the platform before departure. Range 0–180.
Astronomical night
End of astronomical dusk.
Start of astronomical dawn. A time before 12:00 = the morning of the next day.

Source of the night hours: a dated ephemeris that you supply. The Atlas does not provide one in this draft.

Date (optional)
Used only for labels and the clock-change warning. It fetches no data.

How we calculate

  1. Model day: from 12:00 on the day of departure to 11:59 the next day. A time before 12:00 is the morning of the next day, so the night 21:00–04:30 starts before it ends, and the “+1” marker shows the crossing of midnight.
  2. Time at the observing spot runs from arrival + walk to departure − walk − buffer. Unit: minutes. We assume the same walk both ways.
  3. Shared part = max(0, min(end of night, end of stay) − max(start of night, start of stay)). When the intervals do not meet, the result is 0 min — a valid result, not an error.
  4. What is missing: a timetable, ephemerides, a map of the walk or a weather assessment. You enter the times yourself; examples 1–3 are conventional.
  5. Clock change: the calculation follows the nominal clock. Once a date is given, it warns on the night of a clock change but does not correct the result.
Calculation of times (expand)
Arrival18:30 · day of departure
Entry to the observing spot (arrival + walk)19:00 · day of departure
Start of night21:00 · day of departure
End of night04:30 · next day
Exit from the observing spot (departure − walk − buffer)05:25 · next day
Departure06:15 · next day
Shared part21:00 → 04:30 · 7 h 30 min

What the ticket does not check

  • Weather and cloud cover. No stars may mean clouds, not a lack of darkness.
  • The Moon. The percentage of the disc alone does not say whether it is above the horizon — check its rising and setting times for your date. A general rule: the full Moon rises at about sunset; the last quarter, at about midnight.
  • Lighting in the surroundings. The platform and sports facilities may be lit (V2 assumed so — check on site in daylight); do not treat the platform as an observing spot.
  • Night access, park rules and the route. The prototype has no verified sketch of the walk or access hours.
  • Safety. Do not step onto the track or leave the marked trails. If the route or the weather is uncertain, postpone the trip.

Working backwards in three steps

  1. Return. Check the return connection and the operator’s notices for your date. Do not assume a night service. If the night ends later than the train, arrange accommodation before you go.
  2. Daytime. Get to know the place in daylight: access, restrictions, the way back.
  3. Target. With a bright Moon, change the target of your observation; dim the screen and shield the light of your torch.

The park and the place — from V1/V2, to be verified again

2009year the park was established (per V2)
≈75 km²on both sides of the border (per V2)

Izerski Park Ciemnego Nieba (Izera Dark Sky Park) — according to the V2 material, it was established on 4 November 2009 and covers the upper Izera valley, the Jizerka valley and the surrounding ridges on both sides of the border. The park’s name alone does not mean equal darkness everywhere. The data come from earlier versions; no sources were opened in this run.

The stop: V2 gave the name Polana Jakuszycka and line D61. Check the timetable and current disruptions with the operator.

Document missingA photograph of the stop. V2 pointed to a file on Wikimedia Commons, but the prototype works offline and does not embed external images. The rights to the photograph have not been checked here. File page on Commons (not opened in this run).

Sources to verify

  1. Koleje Dolnośląskie — Polana Jakuszycka
    The stop, timetable, disruptions. Linked to the arrival–return interval. Not opened in this run.
  2. Program Ciemne Niebo / POLARIS — Izerski Park
    Date of establishment, area, aims of protecting darkness. Not opened in this run.
  3. NASA — Moon Phases
    Phases of the Moon. The Moon’s rising and setting times must be taken from an ephemeris for the date.
  4. Ephemeris of astronomical dusk and dawn for the Izery: no source named — to be supplied by the editors.