Advanced tool · UTC
Planning guide
Planning studies one object in detail over seven nights from a specific location. It is independent from Visibility, and all calculations, dates, axes and notices use UTC.
Planning and Visibility
Visibility quickly discovers which objects can be photographed during a week from central Catalonia. Planning is for the technical study of one target, with a custom location, night-by-night comparison and five-minute samples.
1 · Location
L’Ampolla —40.80194° N, 0.69361° E— is the initial location. You can enter any latitude and longitude and an optional name.
The location lasts only for the current browser session. Any change marks the calculation as pending and requires observer-dependent data to be recalculated.
2 · Object
Only one input mode can be active: local object, SIMBAD, or manual J2000 RA/Dec.
Resolution order is gallery, pending targets, SIMBAD, then manual coordinates. SIMBAD returns only a name and coordinates for the session and adds nothing to the gallery. Local coordinates prevent an external lookup.
3 · Week and year
Weeks follow ISO Monday-to-Sunday rules. The exact UTC date range appears below the selectors before calculation.
After a change, “Calculate nights” pulses. Calculation runs only when pressed, so selectors can be explored without continuous computation.
4 · Seven-night comparison
Each row summarises astronomical night, maximum night altitude, the effective window above 30°, Moon-down effective time, and the best times with the Moon below or above the horizon.
Illumination and separation refer to the best Moon-up time. A dash means the value does not apply. An outline identifies the night shown in the chart.
Interpreting the Moon
“Moon down” means the Moon is below the horizon within the effective >30° window. When visible, consider illumination, lunar altitude and angular separation together.
Greater separation is usually favourable, but filters, transparency and the target’s surface brightness also matter.
5 · Night detail
The 24-hour chart shows the complete object and Moon curves from −90° to +90°. Shading marks astronomical night, the dashed line marks 30°, and segments outside darkness are dimmed.
Move the pointer—or touch and drag—to inspect the nearest sample: UTC time, object altitude and azimuth, lunar altitude and illumination, Moon–object separation and Sun altitude. Samples are five minutes apart.
Model and limits
Positions are geometric and topocentric, without atmospheric refraction. Moon–object separation is topocentric as well.
Weather, clouds, humidity, terrain, obstructions, local light pollution, transparency and seeing are not modelled. Always check real conditions before a session.