Tonight's target list, checked against the sky before you open the dome

Paste your targets with their coordinates, pick the site and the night. Your browser works out twilight, the dark window, the Moon, and for every target when it rises, transits and sets, how high it gets and how close the Moon comes — free, before you sign in. Then the desk either plans the night into observing windows or checks the plan you already wrote, against the same numbers.

Both examples ship with a saved model run, so you can see a whole plan and a whole check — including the reconciliation — without signing in and without spending a credit.

Site

Site name — for the record

Latitude ° N+

Longitude ° E+

Elevation m

Clock UTC offset, h

Evening of

Altitude floor °

Moon floor ° away

Session optional, HH:MM–HH:MM

Your targets — one per line: name, RA, Dec, then optional priority (p1–p3) and minutes nothing pasted yet

Drag a .txt or .csv in, or Everything is read in your browser. Nothing uploads until you run.

What matters tonight — optional: mount, camera, exposure habits, what to favour

Night facts — free, in your browser, no model

Target	Rise	Transit (alt)	Set	Dark window above floor	Best alt / airmass	Moon	Status

Free — no account, no run. Geometric altitudes, no refraction.

Paste targets to price the run.

lane

targets

scheduled

minutes on sky

statements checked

disagreements

Schedule

#	Target	Start	End	Min	Alt start → end	Airmass	Moon	Why	Checked

Not scheduled

Gaps in the night

Risks

Checklist

Findings, row by row

Line	Slot	Target	Status	Problem	Fix	Browser agrees

Revised sequence

#	Target	Start	End	Min	Alt start → end	Airmass	Moon	Why	Checked

Notes on the draft

Reconciliation with the browser's ephemeris

Every time and altitude the model wrote was re-read against the engine that produced the night facts. A disagreement here means the plan, not the sky, is wrong.

Summary

Raw model reply

The reply did not parse as the structured result, so it is shown as it arrived.

What this does, and what it does not

The night facts are computed, not looked up. Sidereal time, precession to the date, the Sun and the Moon (the full sixty-term series, then the Moon's parallax from your actual position) follow Meeus's Astronomical Algorithms, and the build compared the engine against astropy on 401 checks: stars within 0.6 arcminutes, the Moon within one, twilight within two seconds. Altitudes are geometric — no refraction — which matters below about ten degrees and nowhere a sensible target sits. Every figure the model then writes about the sky is read back against this engine, and the page shows you where the two disagree.

It reads coordinates; it does not look objects up. A name without an RA and Dec is not a target, and there is no catalogue behind the page. It does not know your weather, your seeing, or your horizon profile — a tree in the south-east is your business, and the altitude floor is where you say it. Derived from the agent skill @k-dense-ai/astropy (k-dense-ai/scientific-agent-skills, MIT); not affiliated with the Astropy Project.

Nothing to hand? Load the at Kitt Peak — seven targets, a crescent Moon, one of them below the floor all night — or the at Siding Spring, a five-row draft with two slots the sky refuses. Both replay a saved run for free.