7352 Hypsenor, ''

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 The provisional designation is usually superseded by a permanent designation once a reliable orbit has been calcu ...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 a larger

Jupiter trojan The Jupiter trojans, commonly called trojan asteroids or simply trojans, are a large group of asteroids that share the planet Jupiter's orbit around the Sun. Relative to Jupiter, each trojan librates around one of Jupiter's stable Lagrange poin ...

from the

Trojan camp This is a list of Jupiter trojans that lie in the Trojan camp, an elongated curved region around the trailing Lagrangian point, 60° behind Jupiter. All the asteroids at the trailing point have names corresponding to participants on the Troj ...

, approximately in diameter. The tumbling Jovian

asteroid An asteroid is a minor planet of the inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic or icy bodies with no atmosphere. ...

is a slow rotator with an exceptionally long

rotation period The rotation period of a celestial object (e.g., star, gas giant, planet, moon, asteroid) may refer to its sidereal rotation period, i.e. the time that the object takes to complete a single revolution around its axis of rotation relative to the ...

of 648 hours. It was discovered on 4 February 1994 by Japanese astronomers

Seiji Ueda is a Japanese astronomer. He is a prolific discoverer of minor planets. Between 1987 and 2000, Ueda (in collaboration with Hiroshi Kaneda) discovered 705 asteroids. He holds an MD and Ph.D. from Stanford University and is on the staff at the Gr ...

and Hiroshi Kaneda at the Kushiro Observatory on Hokkaidō, Japan. It was numbered in December 1996, and named after the Trojan warrior Hypsenor from Greek mythology in November 2021.

Classification and orbit

''Hypsenor'' is a

in a 1:1 orbital resonance with Jupiter. It is located in the trailering

at the Gas Giant's

Lagrangian point In celestial mechanics, the Lagrange points (; also Lagrangian points or libration points) are points of equilibrium for small-mass objects under the influence of two massive orbiting bodies. Mathematically, this involves the solution of th ...

, 60 ° behind its orbit . It is also a non- family asteroid of the Jovian background population. It orbits the Sun at a distance of 4.9–5.3 AU once every 11 years and 8 months (4,247 days;

semi-major axis In geometry, the major axis of an ellipse is its longest diameter: a line segment that runs through the center and both foci, with ends at the two most widely separated points of the perimeter. The semi-major axis (major semiaxis) is the long ...

of 5.13 AU). Its orbit has an eccentricity of 0.04 and an inclination of 8 ° with respect to the ecliptic. The body's observation arc begins with a

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

taken at the

Palomar Observatory Palomar Observatory is an astronomical research observatory in San Diego County, California, United States, in the Palomar Mountain Range. It is owned and operated by the California Institute of Technology (Caltech). Research time at the observat ...

in August 1988, more than 5 years prior to its official discovery observation at Kushiro.

Numbering and naming

This minor planet was numbered 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. Function ...

on 24 December 1996 (). On 29 November 2021, IAU's

Working Group for Small Bodies Nomenclature In ancient times, only the Sun and Moon, a few stars, and the most easily visible planets had names. Over the last few hundred years, the number of identified astronomical objects has risen from hundreds to over a billion, and more are discovered ...

it from Greek mythology after the warrior Hypsenor, who was killed during the Trojan War by the Trojan prince Deiphobus whose Javelin throw bounced back of Idomeneus shield.

Physical characteristics

In the SDSS-based taxonomy, ''Hypsenor'' is classified as an X/ L-type. This is unusual as most Jupiter trojans are D-types, with the reminder being mostly C- and

P-type asteroid P-type asteroids are asteroids that have low albedo and a featureless reddish spectrum. It has been suggested that they have a composition of organic rich silicates, carbon and anhydrous silicates, possibly with water ice in their interior. P-type ...

s. It has a V–I color index of 0.85.

Rotation period

In October 2013, a rotational lightcurve was obtained for this asteroid from photometric observations by American amateur astronomer

Robert Stephens Sir Robert Graham Stephens (14 July 193112 November 1995) was a leading English actor in the early years of Britain's Royal National Theatre. He was one of the most respected actors of his generation and was at one time regarded as the natur ...

at the Trojan Station of the

Center for Solar System Studies 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:Observat ...

in Landers, California. It gave a well-defined, outstandingly long

of hours with a brightness variation of 0.30 magnitude (). As of 2018, there are only about three dozens known slow rotators with periods longer than that of ''Hypsenor''.

Tumbler

The astronomers also detected a non-principal axis rotation seen in distinct rotational cycles in successive order. This is commonly known as tumbling. ''Hypsenor'' is the six-largest asteroid and the second-largest Jupiter trojan after 4902 Thessandrus known to be is such a state ''(also see list of tumblers)''.

Diameter and albedo

According to the space-based surveys carried out by the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, ''Hypsenor'' measures 47.07 and 47.73 kilometers in diameter and its surface has an albedo of 0.207 and 0.093, respectively. The ''Collaborative Asteroid Lightcurve Link'' assumes a standard albedo for a

carbonaceous 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 ...

of 0.057 and calculates a larger diameter of 55.67 kilometers, based on an absolute magnitude of 10.0.

Notes

References

External links

Asteroid Lightcurve Database (LCDB)
query form

)

– Minor Planet Center * * {{DEFAULTSORT:Hypsenor 007352 Discoveries by Hiroshi Kaneda Discoveries by Seiji Ueda Named minor planets 007352 19940204