Find the nearest MPC station code
Choose a nearby MPC location for the alert ephemeris. The calculation runs entirely in your browser.
Location and limiting magnitude
Latitude and longitude are processed only on this device for the station search and map. Only when you explicitly choose Create PVGIS horizon are these two coordinates sent once through jostjahn.de to the European Commission PVGIS service. The location button uses browser geolocation only after you grant permission.
The background map becomes progressively more detailed around MPC stations and is deliberately less detailed far away from them. This tiered coverage limits storage use on my web space. The nearest-station calculation still uses the coordinates; only the visible map detail varies.
The nearest station code will appear here after calculation.
The prepared registration mail may also include an experimental personal horizon profile as a plain-text attachment. Alternatively, one number from 0 through 90 after Horizon profile: sets a constant minimum altitude for every azimuth; none removes an existing profile.
Which alerts would have arrived during the last 3 days?
The review uses the station code and limiting magnitude selected above and applies the same basic rules as mail delivery: at least one qualifying ephemeris row within 48 hours, object altitude at or above 0°, solar altitude at or below −6°, and a higher personal horizon where selected.
Scope: At most the ten newest objects no older than three days are included. Whichever limit is reached first applies.
Method: A geocentric ephemeris for MPC code 500 is stored as a station-independent starting point, not as the recipient station. For any other entered station code, the browser recalculates position, distance, and visibility topocentrically. This is not a new complete Find_Orb orbit solution for that station; small differences from the station ephemeris sent at the time are possible, especially for very close objects.
Privacy: The calculation runs entirely in this browser. The public review data contain only objects and geocentric ephemerides, never e-mail addresses, subscriptions, recipient stations, or delivery logs.
Ready for geocentric default station 500 and 20.0 mag.
For newly detected objects, the ephemeris is stored anonymously at alert time. Existing entries are reconstructed with the orbit currently available and may therefore differ slightly from a decision made in real time. This display is guidance, not proof of delivery.
Choose a position on the map
Click the map, mark the desired location, then choose “Use this position”. Latitude and longitude are entered above and the five nearest stations are compared.
PVGIS horizon model
Experimental terrain model: PVGIS includes terrain, but not nearby trees, buildings or domes. Its azimuth convention is converted automatically to the astronomical convention used here: 0° = north, 90° = east, clockwise. The logarithmic altitude scale starts enabled so that small obstructions remain visible; the toggle switches both charts to a linear scale together.
Source and model description: European Commission Joint Research Centre, PVGIS Horizon Profile.
For the ephemeris only
The code is used by this alert service only to approximate horizon, twilight and topocentric position for your location.
For a regularly used site, the Minor Planet Center recommends obtaining your own observatory code. The official observatory-code guide explains the measurements, ADES submission and request form.
MPC code 247, “Roving Observer”, is intended only for a genuinely temporary or one-off site. Each observation then consists of two 80-column records: the first carries an uppercase V in column 15; the second carries a lowercase v, geographic longitude, latitude and altitude; both end in 247. Do not use tabs. Follow the current MPC roving-observer instructions.
The MPC says that the rover format is only for infrequently visited temporary sites. Before submitting, also review the general astrometry and submission rules.