Observations of

minor planet According to the International Astronomical Union (IAU), a minor planet is an astronomical object in direct orbit around the Sun that is exclusively classified as neither a planet nor a comet. Before 2006, the IAU officially used the term ''minor ...

s as well as

comet A comet is an icy, small Solar System body that warms and begins to release gases when passing close to the Sun, a process called outgassing. This produces an extended, gravitationally unbound atmosphere or Coma (cometary), coma surrounding ...

s and

natural satellites A natural satellite is, in the most common usage, an astronomical body that orbits a planet, dwarf planet, or small Solar System body (or sometimes another natural satellite). Natural satellites are colloquially referred to as moons, a deriv ...

of the

Solar System The Solar SystemCapitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Sola ...

are made by

astronomical observatories An observatory is a location used for observing terrestrial, marine, or celestial events. Astronomy, climatology/meteorology, geophysics, oceanography and volcanology are examples of disciplines for which observatories have been constructed. Th ...

all over the world and reported to the

Minor Planet Center The Minor Planet Center (MPC) is the official body for observing and reporting on minor planets under the auspices of the International Astronomical Union (IAU). Founded in 1947, it operates at the Smithsonian Astrophysical Observatory. Funct ...

(MPC), a service of the

International Astronomical Union The International Astronomical Union (IAU; , UAI) is an international non-governmental organization (INGO) with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach, education, and developmen ...

. The MPC maintains a data base that stores all observations submitted by these registered observatories. An

astrometric Astrometry is a branch of astronomy that involves precise measurements of the positions and movements of stars and other celestial bodies. It provides the kinematics and physical origin of the Solar System and this galaxy, the Milky Way. History ...

record consists of the

position Position often refers to: * Position (geometry), the spatial location (rather than orientation) of an entity * Position, a job or occupation Position may also refer to: Games and recreation * Position (poker), location relative to the dealer * ...

brightness Brightness is an attribute of visual perception in which a source appears to be radiating/reflecting light. In other words, brightness is the perception dictated by the luminance of a visual target. The perception is not linear to luminance, and ...

and

timestamp A timestamp is a sequence of characters or encoded information identifying when a certain event occurred, usually giving date and time of day, sometimes accurate to a small fraction of a second. Timestamps do not have to be based on some absolu ...

of an observed object, besides additional information. The database contains more than 200 million records gathered over the past two centuries. The MPC assigns a 3 digit

observatory code This is a list of observatory codes (IAU codes or MPC codes) published by the Minor Planet Center. For a detailed description, ''see observations of small Solar System bodies''. List References {{DEFAULTSORT:Observato ...

for each observatory, also known as 'MPC-' or 'IAU codes'. The code is in the range 000 to Z99 and serves as a unique identifier for the reported observations. The MPC periodically published a revised "List Of Observatory Codes" with newly registered observatories in their ''

Minor Planet Circulars The Minor Planet Center (MPC) is the official body for observing and reporting on minor planets under the auspices of the International Astronomical Union (IAU). Founded in 1947, it operates at the Smithsonian Astrophysical Observatory. Functio ...

''. Over time, the number of astronomical observatories worldwide has been growing constantly and contains 2468 observatory codes . On

numbering There are many different numbering schemes for assigning nominal numbers to entities. These generally require an agreed set of rules, or a central coordinator. The schemes can be considered to be examples of a primary key In the relational model ...

, often years later, the MPC determines the discovery among all the reported observations for an object. This does not need to be the earliest dated observation, ''also see

precovery In astronomy, precovery (short for pre-discovery recovery) is the process of finding the image of a celestial object in images or photographic plates predating its discovery, typically for the purpose of calculating a more accurate orbit. This ha ...

''. The date of the selected observation will become the object's discovery date, and the corresponding observing astronomer or facility will become its discoverer. The discovery circumstances are given in the catalog of numbered minor planets.

Observational record

observational record includes the position, timestamp, and absolute brightness of an observed object. Typically, an observatory observes an objects at least three times within a short timespan during the same night. The records are then reported together with the individual code of the observatory to the

. These are then compared to MPC's internal database and a new

provisional designation Provisional designation in astronomy is the naming convention applied to astronomical objects immediately following their discovery. The provisional designation is usually superseded by a permanent designation once a reliable orbit has been calcu ...

is assigned if no match is found. The observational records are published by the MPC on a weekly basis. Summaries are published in the ''

'' several times a year.

Examples

: The example shows the first observational record for the Jupiter trojan as found in the lower section of the MPC's corresponding object page. The observation was taken on 21 March 1980 at 14 hours 18 minutes and 43 seconds (1980 03 21.59633). The position of the object is given in the

celestial coordinate system In astronomy, coordinate systems are used for specifying positions of celestial objects (satellites, planets, stars, galaxies, etc.) relative to a given reference frame, based on physical reference points available to a situated observer (e. ...

declination In astronomy, declination (abbreviated dec; symbol ''δ'') is one of the two angles that locate a point on the celestial sphere in the equatorial coordinate system, the other being hour angle. The declination angle is measured north (positive) or ...

(DEC) and

right ascension Right ascension (abbreviated RA; symbol ) is the angular distance of a particular point measured eastward along the celestial equator from the Sun at the equinox (celestial coordinates), March equinox to the (hour circle of the) point in questio ...

(RA). The observation was taken by the

Siding Spring Observatory Siding Spring Observatory near Coonabarabran, New South Wales, Australia, part of the Research School of Astronomy & Astrophysics (RSAA) at the Australian National University (ANU), incorporates the Anglo-Australian Telescope along with a coll ...

in Australia and later released by the

Digitized Sky Survey The Digitized Sky Survey (DSS) is a digital data, digitized version of several photography, photographic astronomical surveys of the night sky, produced by the Space Telescope Science Institute between 1983 and 2006. Versions and source materia ...

(DSS) using the observatory's archived

photographic plates Photographic plates preceded photographic film, film as the primary medium for capturing images in photography. These plates, made of metal or Glass, glass and coated with a light-sensitive Photographic emulsion, emulsion, were integral to early ...

with a dedicated

IAU code This is a list of observatory codes (IAU codes or MPC codes) published by the Minor Planet Center. For a detailed description, ''see observations of small Solar System bodies''. List References {{DEFAULTSORT:Observato ...

. The observation was published in the '' Minor Planets and Comets Supplement'' (MPS) on the continual page number 15065 on 21 June 2000.

Astrometric database

MPC's astrometric database contains more than 200 millions entries, split up into 199.9 million minor-planet observations as well as 0.4 million comet- and 0.6 million satellite-observations. The ceremonial first entry, by date, is the discovery observation of made by G. Piazzi on 1 January 1801. Before the end of the 1950s, records were published in a variety of (non-MPC) journals: :

Discovery

Among the observations of an object, one will be determined by the MPC as the discovering observation and its timestamp as the discovery date. This typically happens years after the first observations when an object is numbered and additional observation have secured the object's orbit sufficiently. While the discovery date is typically defined by the object's first obtained observation, there are many exceptions, as the rules for discovery are intricate and have changed over time. For example, an object needs to be observed several times over (at least) two consecutive nights. As nowadays most discoveries are made by dedicated surveys and observing facilities, and the MPC typically does not give credit to more than three individual astronomers, most discoveries of minor planets are credited to a facility (identified by its

) rather than to individual astronomers.

References

External links