1791 Patsayev ( ''prov. designation'': ) is a dark

background asteroid An asteroid family is a population of asteroids that share similar proper orbital elements, such as semimajor axis, eccentricity, and orbital inclination. The members of the families are thought to be fragments of past asteroid collisions. An ...

from the central region of the

asteroid belt The asteroid belt is a torus-shaped region in the Solar System, centered on the Sun and roughly spanning the space between the orbits of the planets Jupiter and Mars. It contains a great many solid, irregularly shaped bodies called asteroids ...

, approximately 26 kilometers in diameter. It was discovered on 4 September 1967, by Russian astronomer Tamara Smirnova at the

Crimean Astrophysical Observatory The Crimean Astrophysical Observatory (CrAO, obs. code: 095) is located at Nauchnij research campus, near the Central Crimean city of Bakhchysarai, on the Crimean peninsula. CrAO is often called simply by its location and campus name ...

in Nauchnyj, on the Crimean peninsula. The asteroid was named after cosmonaut

Viktor Patsayev Viktor Ivanovich Patsayev (; 19 June 193330 June 1971) was a Soviet cosmonaut who flew on the Soyuz 11 mission and was part of the third space crew to die during a space flight. On board the space station Salyut 1 he operated the Orion 1 Spa ...

Orbit and classification

The dark

C-type asteroid C-type (carbonaceous ) asteroids are the most common variety, forming around 75% of known asteroids. They are volatile-rich and distinguished by a very low albedo because their composition includes a large amount of carbon, in addition to rocks ...

orbits the Sun in the central main-belt at a distance of 2.4–3.1 AU once every 4 years and 7 months (1,664 days). Its orbit has an

eccentricity Eccentricity or eccentric may refer to: * Eccentricity (behavior), odd behavior on the part of a person, as opposed to being "normal" Mathematics, science and technology Mathematics * Off-Centre (geometry), center, in geometry * Eccentricity (g ...

of 0.14 and an

inclination Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a reference plane and the orbital plane or axis of direction of the orbiting object. For a satellite orbiting the Eart ...

of 5 ° with respect to the

ecliptic The ecliptic or ecliptic plane is the orbital plane of Earth's orbit, Earth around the Sun. It was a central concept in a number of ancient sciences, providing the framework for key measurements in astronomy, astrology and calendar-making. Fr ...

. ''Patsayev'' was first identified as at

Lowell Observatory Lowell Observatory is an astronomical observatory in Flagstaff, Arizona, United States. Lowell Observatory was established in 1894, placing it among the oldest observatories in the United States, and was designated a National Historic Landmark ...

in 1931, extending the body's

observation arc In observational astronomy, the observation arc (or arc length) of a Solar System body is the time period between its earliest and latest observations, used for tracing the body's path. It is usually given in days or years. The term is mostly use ...

by 36 years prior to its official discovery observation.

Physical characteristics

Rotation period

In April 2016, a rotational

lightcurve In astronomy, a light curve is a graph (discrete mathematics), graph of the Radiance, light intensity of a celestial object or region as a function of time, typically with the magnitude (astronomy), magnitude of light received on the ''y''-axis ...

of ''Patsayev'' was obtained from photometric observations taken by Sydney Black at the Oakley Southern Sky Observatory in Coonabarabran, Australia. It gave a well-defined

rotation period In astronomy, the rotation period or spin period of a celestial object (e.g., star, planet, moon, asteroid) has two definitions. The first one corresponds to the '' sidereal rotation period'' (or ''sidereal day''), i.e., the time that the objec ...

of 19.809 hours with a brightness variation of 0.28 in

magnitude Magnitude may refer to: Mathematics *Euclidean vector, a quantity defined by both its magnitude and its direction *Magnitude (mathematics), the relative size of an object *Norm (mathematics), a term for the size or length of a vector *Order of ...

().

Diameter and albedo

According to the survey carried out by NASA's

Wide-field Infrared Survey Explorer Wide-field Infrared Survey Explorer (WISE, List of observatory codes, observatory code C51, Explorer 92 and MIDEX-6) was a NASA infrared astronomy Space observatory, space telescope in the Explorers Program launched in December 2009.. . WISE L ...

with its subsequent

NEOWISE Wide-field Infrared Survey Explorer (WISE, observatory code C51, Explorer 92 and MIDEX-6) was a NASA infrared astronomy space telescope in the Explorers Program launched in December 2009.. . WISE discovered thousands of minor planets and nu ...

mission, ''Patsayev'' measures between 29.39 and 31.50 kilometers in diameter, and its surface has a high

albedo Albedo ( ; ) is the fraction of sunlight that is Diffuse reflection, diffusely reflected by a body. It is measured on a scale from 0 (corresponding to a black body that absorbs all incident radiation) to 1 (corresponding to a body that reflects ...

between 0.030 and 0.039. The ''Collaborative Asteroid Lightcurve Link'' (CALL) disagrees with the results found by WISE. CALL derives a much lower carbonaceous albedo of 0.046, and calculates a diameter of 25.69 kilometers with an absolute magnitude of 11.9.

Naming

This

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 ...

was named in honor of Russian–Soviet cosmonaut

(1933–1971), test Engineer of the

Soyuz 11 Soyuz 11 () was the only crewed mission to board the world's first space station, Salyut 1. The crew, Georgy Dobrovolsky, Vladislav Volkov, and Viktor Patsayev, arrived at the space station on 7 June 1971, and departed on 29 June 1971. The ...

spacecraft, who died on his first spaceflight on 30 June 1971 during the vehicle's return to Earth after completing the flight program of the first crewed orbital station,

Salyut The ''Salyut'' programme (, , meaning "salute" or "fireworks") was the first space station programme, undertaken by the Soviet Union. It involved a series of four crewed scientific research space stations and two crewed military reconnaissa ...

. The lunar crater '' Patsaev'' is also named after him. The precedingly numbered minor planets 1789 Dobrovolsky and 1790 Volkov were named in honour of his dead crew members. The names of all three cosmonauts are also engraved on the plaque next to the sculpture of the ''

Fallen Astronaut ''Fallen Astronaut'' is a aluminum sculpture created by Belgian artist Paul Van Hoeydonck. It is a stylized figure of an astronaut in a spacesuit, intended to commemorate the astronauts and Astronaut#Cosmonaut, cosmonauts who have died in t ...

'' on the Moon, which was placed there during the

Apollo 15 Apollo 15 (July 26August 7, 1971) was the ninth crewed mission in the Apollo program and the fourth Moon landing. It was the first List of Apollo missions#Alphabetical mission types, J mission, with a longer stay on the Moon and a greate ...

mission, containing the names of eight American astronauts and six Soviet cosmonauts, who had all died in service. The official was published by 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 ...

on 1 July 1972 ().

References

External links

Asteroid Lightcurve Database (LCDB)
query form

)
Dictionary of Minor Planet Names
Google books

– Observatoire de Genève, Raoul Behrend

– Minor Planet Center * * {{DEFAULTSORT:Patsayev 001791 Discoveries by Tamara Mikhaylovna Smirnova Named minor planets 19670904