Ra-Shalom orbits the Sun at a distance of 0.5–1.2
AU once every 9 months (277 days). Its orbit has an
eccentricity of 0.44 and an
inclination of 16
° with respect to the
ecliptic.[1]
It was the second
Aten asteroid to be discovered after
2062 Aten, the family's namesake, also discovered by Helin in 1976. The group of Aten asteroids feature a
semi-major axis of less than 1 AU. Of this group, Ra-Shalom has one of the smallest semi-major axes, just 0.832 AU.
The
minor planet's composed named was chosen by the discoverer to commemorate the
Camp David Peace Accords between Egypt and Israel in September 1978, and as a symbol for the universal hope for peace.
Ra is the Egyptian Sun-god, who symbolizes enlightenment and life, while
Shalom is the traditional Hebrew greeting meaning peace.[3] The official
naming citation was published by the
Minor Planet Center on 1 November 1978 (M.P.C. 4548).[22]
Physical characteristics
Ra-Shalom has been characterized as a
C-type and
X-type asteroid on the
Tholen and
SMASS taxonomic scheme, respectively.[1] It has also been characterized as a
K-type asteroid.[9] In 1981, the asteroid was detected using radar, revealing a relatively smooth surface at decimeter scales.[23]
Rotation period
In August 2016, a rotational
lightcurve of Ra-Shalom was obtained from photometric observations by American astronomer
Brian Warner. Lightcurve analysis gave a well-defined
rotation period of 19.89 hours with a brightness amplitude of 0.55
magnitude (U=3).[18]
A large number of previous photometric observations gave a period between 19.79 and 19.8201 hours with a brightness amplitude between 0.3 and 0.41
magnitude.[9][14][15][a][16][17]
Diameter and albedo
According to
Spitzer Space Telescope's ExploreNEOs survey, the Japanese
Akari satellite, and NASA's
Keck Observatory, Ra-Shalom measures between 1.98 and 2.79 kilometers in diameter and its surface has an
albedo between 0.080 and 0.177.[5][6][7][8][9][10][11][13] The Collaborative Asteroid Lightcurve Link adopts an albedo of 0.082 and a diameter of 2.78 kilometers with an
absolute magnitude of 16.054.[12]
^Schmadel, Lutz D. (2009). "Appendix – Publication Dates of the MPCs". Dictionary of Minor Planet Names – Addendum to Fifth Edition (2006–2008). Springer Berlin Heidelberg. p. 221.
doi:
10.1007/978-3-642-01965-4.
ISBN978-3-642-01964-7.