Naked-eye almanac · Issue Nineteen

The sky over Ash Down, looking up at 22:40.

A whole-hemisphere plot drawn for the flat field behind the observatory shed. Drag the hour dial and the dome turns beneath a fixed horizon, exactly as it does when you stand still long enough to notice.

Epoch J2000.0 · precessed to 2026.55 Site Ash Down Field Station, alt. 214 m Conditions Bortle 4 · transparency good Plot Stereographic, zenith-centred
22:40

Field log — night of 18 July

Four observers · one thermos

21:52

Arcturus first out of the dusk

Amber and unmistakable in the west while the sky was still the colour of weak tea. Everything else waited another twenty minutes.

22:40

Summer Triangle fully clear

Vega near enough overhead to hurt your neck, Deneb trailing, Altair low and flickering through the warm air off the barn roof.

23:31

Perseid, early and generous

Long green streak out of the north-east, five or six seconds of train. Nobody had a camera pointed the right way, as usual.

01:08

Mist to knee height

Ground fog crept in from the ditch and swallowed the horizon ring below about six degrees. Transparency overhead unaffected.

Working catalogue

Every star plotted on the chart above, in order of brightness. Click a row to move the selection ring on the dome.

Stars plotted on the chart
StarDesignationFigureMagAltAzClass