6070 Rheinland ( ''prov. designation'': ) is a paired Nysian asteroid from the inner regions of the

asteroid belt The asteroid belt is a torus-shaped region in the Solar System, located roughly between the orbits of the planets Jupiter and Mars. It contains a great many solid, irregularly shaped bodies, of many sizes, but much smaller than planets, c ...

, approximately in diameter. It was discovered on 10 December 1991, by German astronomer Freimut Börngen at the

Karl Schwarzschild Observatory The Karl Schwarzschild Observatory (german: Karl-Schwarzschild-Observatorium) is a German astronomical observatory in Tautenburg near Jena, Thuringia. It was founded in 1960 as an affiliated institute of the former German Academy of Sciences at ...

in Tautenburg, Germany. The asteroid was named after the

Rhineland The Rhineland (german: Rheinland; french: Rhénanie; nl, Rijnland; ksh, Rhingland; Latinised name: ''Rhenania'') is a loosely defined area of Western Germany along the Rhine, chiefly its middle section. Term Historically, the Rhinelands ...

, a region in western Germany. The stony asteroid has a rotation period of 4.27 hours.

Orbit and classification

''Rheinland'' is a member of the

Nysa family The Nysa family (adj. ''Nysian''; FIN: 405) is part of the Nysa–Polana complex, the largest cluster of asteroid families in the asteroid belt. It is located in the inner region of the asteroid belt, orbiting the Sun between 2.41 and 2.5 A ...

(), the largest asteroid family that can be divided further into subfamilies with different spectral properties. It orbits the Sun in the inner main-belt at a distance of 1.9–2.9 AU once every 3 years and 8 months (1,347 days; semi-major axis of 2.39 AU). 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 0.21 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 3 ° with respect to the

ecliptic The ecliptic or ecliptic plane is the orbital plane of the Earth around the Sun. From the perspective of an observer on Earth, the Sun's movement around the celestial sphere over the course of a year traces out a path along the ecliptic agains ...

. The asteroid was first observed as at

Heidelberg Observatory Heidelberg (; Palatine German: ') is a city in the German state of Baden-Württemberg, situated on the river Neckar in south-west Germany. As of the 2016 census, its population was 159,914, of which roughly a quarter consisted of student ...

in October 1950. 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 ...

begins with a precovery taken at the Palomar Observatory in March 1956, more than 35 years prior to its official discovery observation at Tautenburg.

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 ''mino ...

was named after the

, a region in western Germany. The official naming citation was published by the Minor Planet Center on 17 March 1995 ().

Physical characteristics

''Rheinland'' has been characterized as an S- and

Q-type asteroid Q-type asteroids are relatively uncommon inner-belt asteroids with a strong, broad 1 micrometre olivine and pyroxene feature, and a spectral slope that indicates the presence of metal. There are absorption features shortwards and longwards of 0. ...

by Pan-STARRS photometric survey. It is also characterized as a stony

S-type asteroid S-type asteroids are asteroids with a spectral type that is indicative of a siliceous (i.e. stony) mineralogical composition, hence the name. They have relatively high density. Approximately 17% of asteroids are of this type, making it the secon ...

in the SDSS–MFB taxonomy (Masi Foglia Binzel).

Rotation period and poles

Several rotational

lightcurve In astronomy, a light curve is a graph of light intensity of a celestial object or region as a function of time, typically with the magnitude of light received on the y axis and with time on the x axis. The light is usually in a particular freq ...

s of ''Rheinland'' have been obtained from photometric observations since 2009. Analysis of the best-rated lightcurve gave a rotation period of 4.27333 hours with a consolidated brightness amplitude between 0.40 and 0.58

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 ...

(). Published in 2014, a modeled lightcurve gave a period 4.273715 hours, as well as a two spin axes of (110.0°, −60.0°) and (290°, −60.0°) in

ecliptic coordinates The ecliptic coordinate system is a celestial coordinate system commonly used for representing the apparent positions, orbits, and pole orientations of Solar System objects. Because most planets (except Mercury) and many small Solar System bodi ...

(λ, β). In 2017, modelling gave a period of and a single spin axis of (124°, −87.0°), refining a previously published result of and (4°, −76.0°).

Diameter and albedo

According to a detailed study published in 2017, ''Rheinland'' measures 4.4 kilometers in diameter and its surface has an

albedo Albedo (; ) is the measure of the diffuse reflection of solar radiation out of the total solar radiation and measured on a scale from 0, corresponding to a black body that absorbs all incident radiation, to 1, corresponding to a body that refl ...

of 0.20, while the ''Collaborative Asteroid Lightcurve Link'' also assumes an albedo of 0.20 and derives a similar diameter of 4.36 kilometers based on an

absolute magnitude Absolute magnitude () is a measure of the luminosity of a celestial object on an inverse logarithmic astronomical magnitude scale. An object's absolute magnitude is defined to be equal to the apparent magnitude that the object would have if it ...

of 14.17.

Asteroid pair

''Rheinland'' forms an asteroid pair with asteroid , a newly found class of two unbound bodies on nearly identical orbits around the Sun. Asteroid pairs have not been studied in detail yet. In the past, the members of a pair (or cluster if more than two members) had very small relative velocities and may have been a

binary asteroid A binary asteroid is a system of two asteroids orbiting their common barycenter. The binary nature of 243 Ida was discovered when the Galileo spacecraft flew by the asteroid in 1993. Since then numerous binary asteroids and several triple a ...

until they became gravitationally unbound and continued on separate orbits. Other asteroid pairs may have resulted from a collisional breakup of a

parent body In meteoritics, a parent body is the celestial body from which originates a meteorite or a class of meteorites. Identification The easiest way to correlate a meteorite with a parent body is when the parent body still exists. This is the case fo ...

similar to the process that formed the asteroid families. It is thought that this pair was created due to rotational fission (

YORP effect Yorp or YORP may refer to one of the following: * 54509 YORP, an Earth co-orbital asteroid * Yarkovsky–O'Keefe–Radzievskii–Paddack effect, a second-order variation on the Yarkovsky effect *Yorps, friendly one-eyed Martians from the Commander ...

) some years ago. The other body of this pair, , has a diameter of approximately 2.09 kilometers, an albedo of 0.213, and is an assumed

Notes

References

External links

Formation of asteroid pairs by rotational fission
''Nature'' (2010)
Lightcurve Database Query
(LCDB), at ''www.minorplanet.info''
Dictionary of Minor Planet Names
Google books

– ''Geneva Observatory'', Raoul Behrend

– Minor Planet Center * * {{DEFAULTSORT:Rheinland 006070 Discoveries by Freimut Börngen Named minor planets 19911210