1998 Titius, provisional designation , is a metallic–carbonaceous

asteroid An asteroid is a minor planet—an object larger than a meteoroid that is neither a planet nor an identified comet—that orbits within the Solar System#Inner Solar System, inner Solar System or is co-orbital with Jupiter (Trojan asteroids). As ...

from the inner regions 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 14 kilometers in diameter. It was discovered on 24 February 1938, by German astronomer Alfred Bohrmann at

Heidelberg Observatory Heidelberg (; ; ) is the List of cities in Baden-Württemberg by population, fifth-largest city in the States of Germany, German state of Baden-Württemberg, and with a population of about 163,000, of which roughly a quarter consists of studen ...

in southern Germany. On the same night, the body was also observed at the Finnish

Turku Observatory Turku ( ; ; , ) is a city in Finland and the regional capital of Southwest Finland. It is located on the southwestern coast of the country at the mouth of the Aura River (Finland), River Aura. The population of Turku is approximately , while t ...

. It was later named after astronomer

Johann Daniel Titius Johann Daniel Titius (born Johann Daniel Tietz(e), 2 January 1729 – 16 December 1796) was a German astronomer and a professor at Wittenberg.

Orbit and classification

''Titius'' orbits the Sun in the inner main-belt at a distance of 2.3–2.6 AU once every 3 years and 9 months (1,375 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 0.06 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 8 ° 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 ...

. It stays in a 2:1

orbital resonance In celestial mechanics, orbital resonance occurs when orbiting bodies exert regular, periodic gravitational influence on each other, usually because their orbital periods are related by a ratio of small integers. Most commonly, this relation ...

with the planet

Mars Mars is the fourth planet from the Sun. It is also known as the "Red Planet", because of its orange-red appearance. Mars is a desert-like rocky planet with a tenuous carbon dioxide () atmosphere. At the average surface level the atmosph ...

. ''Titius''

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 ...

starts on the night following its official discovery observation.

Physical characteristics

Diameter and albedo

According to observations carried out by the Japanese Akari and 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 ...

(WISE) 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, ''Titius'' has an

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 0.093 and 0.126, and its diameter measures between 14.2 and 16.0 kilometers. The ''Collaborative Asteroid Lightcurve Link'' assumes a standard albedo of 0.20 and calculates a diameter of 10.8 kilometers with an absolute magnitude of 12.2.

Spectral type

Its

spectral classification ''Spectral'' is a 2016 Hungarian-American military science fiction action film co-written and directed by Nic Mathieu. Written with Ian Fried & George Nolfi, the film stars James Badge Dale as DARPA research scientist Mark Clyne, with Max M ...

is that of a Xc-type asteroid in the SMASS taxonomy, a transitional spectral type between the two large main groups of metallic X-type and carbonaceous C-type asteroids. Both types are much darker than the stony S-type asteroids, which are also very common in the inner main-belt. In addition, ''Titius'' is also classified as a M-type asteroid by WISE.

Rotation period

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 ''Titius'' was obtained from photometric observations by American astronomer Robert Stephens at the Californian Santana Observatory in March 2002. Lightcurve analysis gave a

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 hours, during which its brightness amplitude varies by

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 ...

().

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 after German astronomer

Johann Daniel Titius Johann Daniel Titius (born Johann Daniel Tietz(e), 2 January 1729 – 16 December 1796) was a German astronomer and a professor at Wittenberg.

(1729–1796), best known for formulating the Titius-Bode law, which states that each subsequent planet in the Solar System is roughly twice as far from the Sun than the previous one. He is also honored by the lunar crater '' Titius''. 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 15 October 1977 ().

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:Titius 001998 Discoveries by Alfred Bohrmann Named minor planets 001998 19380224