Rheinland is a member of the Nysa family (405),[3] the largest asteroid family that can be divided further into subfamilies with different spectral properties.[13]: 23
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 of 0.21 and an inclination of 3° with respect to the ecliptic.[2] The asteroid was first observed as 1950 TW1atHeidelberg Observatory in October 1950. The body's observation arc begins with a precovery taken at the Palomar Observatory in March 1956, more than 35 years prior to its official discovery observation at Tautenburg.[1]
Rheinland has been characterized as an S- and Q-type asteroid by Pan-STARRS' photometric survey.[11] It is also characterized as a stony S-type asteroid in the SDSS–MFB taxonomy (Masi Foglia Binzel).[4][b]
Several rotational lightcurvesofRheinland have been obtained from photometric observations since 2009.[6][9][10][a] 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 (U=3).[4]
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 (λ, β).[8] In 2017, modelling gave a period of 4.2737137h and a single spin axis of (124°, −87.0°),[5] refining a previously published result of 4.27371h and (4°, −76.0°).[7]
According to a detailed study published in 2017, Rheinland measures 4.4 kilometers in diameter and its surface has an albedo of 0.20,[5] 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 of 14.17.[4]
Rheinland forms an asteroid pair with asteroid (54827) 2001 NQ8, 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 until they became gravitationally unbound and continued on separate orbits. Other asteroid pairs may have resulted from a collisional breakup of a parent body similar to the process that formed the asteroid families.[15]
It is thought that this pair was created due to rotational fission (YORP effect) some 16340±40 years ago.[5] The other body of this pair, 2001 NQ8, has a diameter of approximately 2.09 kilometers, an albedo of 0.213, and is an assumed Q-type asteroid.[16][15]
^ abSearch for Unusual Spectroscopic Candidates Among 40313 minor planets from the 3rd Release of the Sloan Digital Sky Survey Moving Object Catalog (publication). SDSS-MFB (Masi Foglia Binzel) taxonomy (catalog).
^ abcVeres, Peter; Jedicke, Robert; Fitzsimmons, Alan; Denneau, Larry; Granvik, Mikael; Bolin, Bryce; et al. (November 2015). "Absolute magnitudes and slope parameters for 250,000 asteroids observed by Pan-STARRS PS1 - Preliminary results". Icarus. 261: 34–47. arXiv:1506.00762. Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007. S2CID53493339.
^Pravec, Petr; Harris, Alan W.; Kusnirák, Peter; Galád, Adrián; Hornoch, Kamil (September 2012). "Absolute magnitudes of asteroids and a revision of asteroid albedo estimates from WISE thermal observations". Icarus. 221 (1): 365–387. Bibcode:2012Icar..221..365P. doi:10.1016/j.icarus.2012.07.026.
