For amateurs
Every word, in plain words.
If a word on this site is new to you, it is here. Nobody was born knowing what an ADES file is.
The words
- 80-column (the MPC's format)
- The MPC's oldest format, still in use: one line of exactly 80 characters for each observation, every part in its own columns. It looks like a wall of digits, and it is meant to.
- A plain table
- Just columns: the time, the right ascension, the declination, and if you have them the brightness and your station, separated by spaces, commas or tabs.
- ACK acknowledgement
- A line in a report to the MPC that names your submission, so the MPC's acknowledgement can be matched to it. A survivor's report writes one for you.
- ADES Astrometry Data Exchange Standard
- The MPC's newer format. Every value is named, so nothing depends on columns. It comes in two spellings, PSV and XML.
- Candidate and discovery
- A candidate is what you have before anyone checks. A discovery is what a desk confirms afterwards.
- Check, gate
- Skyptic runs ten checks, each marked with a letter, in the order that kills most candidates earliest. A candidate has to get through all of them.
- Designation
- The name the MPC gives an object, like 2026 AB1, or a number like (13243) once its orbit is well known.
- digest2
- The MPC's own tool that gives the NEO score.
- FITS
- The standard file format for astronomical images.
- Gaia
- The European Space Agency's catalogue of about two billion stars. Skyptic asks it whether your "mover" is really a star that does not move.
- Known object
- Something the MPC already has an orbit for. Most first detections turn out to be one.
- MPC Minor Planet Center
- The place that collects every measured position of asteroids and comets, and gives them their names. It is where a real discovery is reported.
- NEO near-Earth object
- An asteroid or comet whose orbit brings it close to the Earth's.
- NEO score
- A number from 0 to 100 from the MPC's digest2 tool: how likely an unidentified object is to be a near-Earth object. At 65 or more, the MPC's NEO Confirmation Page is the right desk.
- NEOCP NEO Confirmation Page
- The MPC's public list of new, unidentified objects that need a second observer. It is time-critical: a new object can be lost within a night or two.
- Observation, detection, row
- One measured position of one object: when you saw it, where in the sky, how bright, and from where. Skyptic calls each one a row.
- PSV pipe-separated values
- ADES as plain text, with a | between the values.
- RA and Dec right ascension and declination
- The sky's longitude and latitude. Together they say where in the sky something is.
- SatChecker
- A service of the IAU that works out where satellites are at a given time, so a satellite trail is not mistaken for an asteroid.
- SkyBoT
- A service from the Paris observatory (IMCCE) that lists the known solar-system objects in a patch of sky. Skyptic asks it for a second opinion in the deep mode.
- SNR signal-to-noise ratio
- How far above the background noise something stands. A low number may only be noise.
- Station code also: observatory code
- A 3-character code the MPC gives every observatory, like T08. The MPC needs it to know where on Earth you stood, because a nearby object shifts against the stars depending on where you look from. No code? Leave it empty and the checks use the centre of the Earth, which is less exact.
- The arcsecond mark (")
- An arcsecond is a 3,600th of a degree, written ". It is the unit for how far apart two positions are, and for how well a measurement is known.
- Tracklet
- The observations of one object over a short time, usually one night: enough to see that it moves, not enough to know its orbit.
- trkSub
- A temporary label that keeps the rows of one tracklet together when you paste several. Any short label will do.
- WAMO Where Are My Observations
- The MPC's service that tells you whether it already holds your rows.
- WCS world coordinate system
- The part of a FITS file's header that says which pixel is which place in the sky. Without it, Skyptic cannot find your candidate in the frame.
- XML
- ADES as tagged text, with the values between angle brackets like <ra>21.5</ra>.
The verdicts
- Known KNOWN
- The MPC already has an orbit for this object, and it is where your rows are.
- Satellite SATELLITE
- A catalogued satellite was at your place, at your times, moving as your rows move.
- Star STAR
- Your rows sit on a fixed star. Nothing moved.
- Not one body NOT_ONE_BODY
- Your rows do not lie on one smooth line: they are different objects.
- No orbit NO_ORBIT
- With several nights, no single orbit goes through your rows.
- Not moving STATIC
- A fixed source, for another desk.
- Near the Earth EARTHBOUND
- It is near the Earth, and no catalogued satellite matches.
- Held HELD
- Nothing killed it yet, and the verdict lists what it needs.
- Survivor SURVIVOR
- Every check that could run, passed. That makes it a candidate worth a desk's time; the follow-up decides whether it is a discovery.
- Nothing read UNREAD
- Nothing could be read from what you pasted.