astrocamp AstroPlanner grew out of a personal spreadsheet I used to plan my astrophotography nights. The result is a WordPress plugin that calculates, for any Deep Sky object and any location on Earth, how high the object stands at any given time, when it reaches its optimal culmination, and when the night is dark enough to observe. The complete Messier catalogue is directly selectable, personal object lists can be maintained, and SIMBAD lookup covers hundreds of catalogues.
The plugin is currently embedded exclusively on this site. That may change if there’s demand.
Object Selection
The complete Messier catalogue (M1–M110) is available via a drop-down menu, with English object names throughout.
Killer Feature
The Messier list can be sorted either by catalogue number (No.) or by culmination date (Culm.). When sorted by culmination date, pressing the down arrow key steps through the entire catalogue in chronological order – from the January sky to December, always following the sequence in which objects reach their best position at night.
A second drop-down menu (My Objects) lets you manage a personal object list. The list is maintained in the WordPress backend – simply enter object names, and the planner resolves coordinates automatically via SIMBAD.
The free-text field (SIMBAD-Search) allows direct lookup in the SIMBAD database of the Université de Strasbourg. Supported catalogues with example syntax:
- Messier:
M5orMessier 5 - Sharpless:
Sh2-106 - NGC:
NGC 7000 - IC:
IC 1805 - PGC / UGC:
PGC 1234 - LDN / LBN:
LDN 1622 - van den Bergh:
vdB 31 - Melotte:
Melotte 15orMel 15
Spaces between catalogue prefix and number can usually be omitted. SIMBAD covers many more catalogues – searching is half the fun.
For edge cases, Right Ascension (RA) and Declination (Dec) can be entered manually in HH MM SS and ±DD MM SS format.
Observer Location
The default location is Observatorium Hoher List in the Vulkaneifel, Germany – one of my favourite observing sites.
A drop-down menu offers around 40 locations worldwide, from Anchorage to Auckland, grouped alphabetically by continent. Time zones and daylight saving time are handled automatically.
Latitude and longitude can also be entered freely for any custom location.
Culmination at Astron. Midnight
The meridian culmination at astronomical midnight is the one moment in the year when a Deep Sky object reaches its highest point above the horizon at exactly the same time as the Sun is at its lowest – the darkest hour of the darkest night. That night, the object is as high as it ever gets and the sky is as dark as it can be.
The planner displays this moment as a date and local time, along with the altitude the object reaches. A red line in the table marks the optimal month visually.
I love this value – not because I strictly need it for planning, but because it lets me sort objects chronologically, independent of any catalogue or human-defined category.
Table Layout
The table shows the months January through December horizontally and local time from 18:00 to 06:00 vertically. Calculations use the 15th of each month as the representative date.
- Empty cell: The object is below the horizon.
- Steel blue: The object is above the horizon, but the Sun is still too high (above −12°) – too bright for Deep Sky work.
- Coloured, italic: Astronomical twilight (Sun between −12° and −18°) – already observable, but not yet fully dark.
- Coloured, normal: Astronomical night (Sun below −18°) – optimal conditions.
The colour scale from red to dark green represents the altitude in degrees above the horizon. The exact mapping is shown in the legend below the table.
The numbers are approximate, but accurate enough for planning purposes.
Additional Features
- Copy Link: Copies a direct link to the current view, including object and location. Useful for sharing or linking from blog posts.
- Shortcode: Individual objects can be embedded in any WordPress page using the shortcode. The table appears immediately with the preset object; the visitor can still change the location.
Feedback
Comments are very welcome – praise, criticism, ideas for improvement, and bug reports alike.