2100 Ra-Shalom

Last updated

2100 Ra-Shalom
002100-asteroid shape model (2100) Ra-Shalom.png
Shape model of Ra-Shalom from its lightcurve
Discovery [1]
Discovered by E. F. Helin
Discovery site Palomar Obs.
Discovery date10 September 1978
Designations
(2100) Ra-Shalom
Pronunciation /ˌrɑːʃəˈlm/ [2]
Named after
Ra and Shalom
(composed name) [3]
1978 RA ·1975 TB
NEO  · Aten [1] [4]
Orbital characteristics [1]
Epoch 7 November 2005 (JD 2453681.5)
Uncertainty parameter 0
Observation arc 41.07 yr (14,999 days)
Aphelion 1.1952 AU
Perihelion 0.4688 AU
0.8320 AU
Eccentricity 0.4365
0.76 yr (277 days)
104.56°
Inclination 15.756°
170.88°
355.98°
Earth  MOID 0.1496 AU ·58.3 LD
Physical characteristics
Mean diameter
1.98±0.05 km [5]
2.04 km [6]
2.22 km [7]
2.24 km [8]
2.3±0.2 km [9]
2.48 km [10]
2.78 km [11] [12]
2.79 km [13]
19.79±0.03 h [14]
19.793±0.001 h [9]
19.797 h [15] [lower-alpha 1]
19.79981 h [16]
19.8201±0.00004 h [17]
19.89±0.05 [18]
0.080 [13]
0.082 [11] [12]
0.125 [10]
0.13±0.03 [9] [8]
0.14±0.10 [19]
0.16 [6]
0.177±0.009 [5]
C (Tholen) [1]  ·Xc (SMASS) [1]
C (CALL) [12]  · K [9]
B–V = 0.712 [1]
U–B = 0.310 [1]
15.66±0.1(R) [lower-alpha 1]  ·15.90 [10]  ·16.05 [1] [5]  ·16.054±0.07 [12] [20]  ·16.06±0.07 [14]  ·16.06 [6]  ·16.07 [15]  ·16.1 [7]  ·16.11 [11]

    2100 Ra-Shalom (prov. designation: 1978 RA) is an asteroid and near-Earth object of the Aten group on an eccentric orbit in the inner Solar System. It was discovered on 10 September 1978, by American astronomer Eleanor Helin at the Palomar Observatory, California, who named it in commemoration of the Camp David Peace Accords. [3] [4] The C-type asteroid (Xc, K) has a rotation period of 19.8 hours and measures approximately 2.7 kilometers (1.7 miles) in diameter.

    Contents

    Orbit and classification

    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 asteroid has an Earth minimum orbital intersection distance of 0.1496 AU (22,400,000 km) which corresponds to 58.3 lunar distances, far too large to make it a potentially hazardous object. [1] It also comes within 30  gigameter (Gm) of Mars, Venus and Mercury. The closest approaches are to Mercury, to about 0.0784 AU (11.7 Gm). [21]

    Naming

    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

    Lightcurve based 3D-model of Ra-Shalom 2100Ra-Shalom (Lightcurve Inversion).png
    Lightcurve based 3D-model of Ra-Shalom

    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] [lower-alpha 1] [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]

    Notes

    1. 1 2 3 Pravec (2003) web: rotation period 19.797 hours with a brightness amplitude of 0.34 in magnitude. Period Identical with Pravec's observation in 1998. Summary figures at Collaborative Asteroid Lightcurve Link (CALL) for (2100) Ra-Shalom

    Related Research Articles

    <span class="mw-page-title-main">1620 Geographos</span> Asteroid

    1620 Geographos is a highly elongated, stony asteroid, near-Earth object and potentially hazardous asteroid of the Apollo group, with a mean-diameter of approximately 2.5 km (1.6 mi). It was discovered on 14 September 1951, by astronomers Albert George Wilson and Rudolph Minkowski at the Palomar Observatory in California, United States. The asteroid was named in honor of the National Geographic Society.

    2063 Bacchus, provisional designation 1977 HB, is a stony asteroid and near-Earth object of the Apollo group, approximately 1 kilometer in diameter. The contact binary was discovered on 24 April 1977, by American astronomer Charles Kowal at the Palomar Observatory in California, United States. It was named after Bacchus from Roman mythology.

    <span class="mw-page-title-main">2062 Aten</span> Sub-kilometer asteroid

    2062 Aten, provisional designation 1976 AA, is a stony sub-kilometer asteroid and namesake of the Aten asteroids, a subgroup of near-Earth objects. The asteroid was named after Aten from Egyptian mythology.

    (99907) 1989 VA is a very eccentric, stony asteroid and near-Earth object, approximately 1 kilometer in diameter. It was discovered on 2 November 1989, by American astronomer couple Carolyn and Eugene Shoemaker and Canadian astronomer David Levy at the Palomar Observatory on Mount Palomar, California.

    <span class="mw-page-title-main">1627 Ivar</span>

    1627 Ivar is an elongated stony asteroid and near-Earth object of the Amor group, approximately 15×6×6 km. It was discovered on 25 September 1929, by Danish astronomer Ejnar Hertzsprung at Leiden Southern Station, annex to the Johannesburg Observatory in South Africa. It was named after Ivar Hertzsprung, brother of the discoverer. 1627 Ivar was the first asteroid to be imaged by radar, in July 1985 by the Arecibo Observatory.

    1863 Antinous, provisional designation 1948 EA, is a stony asteroid and near-Earth object, approximately 2–3 kilometers in diameter. It was discovered on 7 March 1948 by American astronomer Carl Wirtanen at Lick Observatory on the summit of Mount Hamilton, California. It was named after Antinous from Greek mythology.

    <span class="mw-page-title-main">1865 Cerberus</span>

    1865 Cerberus is a stony asteroid and near-Earth object of the Apollo group, approximately 1.6 kilometers in diameter. It was discovered on 26 October 1971, by Czech astronomer Luboš Kohoutek at the Hamburger Bergedorf Observatory, Germany, and given the provisional designation 1971 UA. It was named for Cerberus from Greek mythology.

    3757 Anagolay, provisional designation 1982 XB, is a highly eccentric asteroid, classified as a potentially hazardous asteroid and a near-Earth object of the Amor group, approximately half a kilometer in diameter. It was discovered on 14 December 1982, by American astronomer Eleanor Helin at the Palomar Observatory in California, United States. The asteroid was named after Anagolay from Philippine mythology.

    8034 Akka, provisional designation 1992 LR, is a sub-kilometer sized, eccentric asteroid and near-Earth object of the Apollo group, approximately 540 meters in diameter. It was discovered at Palomar Observatory in 1992, and named after Akka from Finnish mythology.

    1943 Anteros, provisional designation 1973 EC, is a spheroidal, rare-type asteroid and near-Earth object of the Amor group, approximately 2 kilometers in diameter.

    <span class="mw-page-title-main">1580 Betulia</span>

    1580 Betulia, provisional designation 1950 KA, is an eccentric, carbonaceous asteroid, classified as near-Earth object of the Amor group, approximately 4.2 kilometers in diameter. It was discovered on 22 May 1950, by South African astronomer Ernest Johnson at the Union Observatory in Johannesburg. The asteroid was named for Betulia Toro, wife of astronomer Samuel Herrick.

    1916 Boreas, provisional designation 1953 RA, is an eccentric, stony asteroid and near-Earth object of the Amor group, approximately 3 kilometers in diameter. After its discovery in 1953, it became a lost asteroid until 1974. It was named after Boreas from Greek mythology.

    4957 Brucemurray, provisional designation 1990 XJ, is a stony asteroid, classified as near-Earth object of the Amor group and as Mars-crosser, approximately 3 kilometers in diameter. It was discovered by American astronomer Eleanor Helin at the Palomar Observatory in California on 15 December 1990. The asteroid was named after American planetary scientist Bruce C. Murray.

    <span class="mw-page-title-main">5143 Heracles</span>

    5143 Heracles(provisional designation 1991 VL) is a highly eccentric, rare-type asteroid and synchronous binary system, classified as near-Earth object of the Apollo group, approximately 4.8 kilometers in diameter. The asteroid was discovered on 7 November 1991, by American astronomer Carolyn Shoemaker at Palomar Observatory in California, United States. It is named for the Greek divine hero Heracles. It has an Earth minimum orbit intersection distance of 0.058 AU (8.7 million km) and is associated with the Beta Taurids daytime meteor shower.

    3102 Krok, provisional designation 1981 QA, is a rare-type asteroid and slow rotator, classified as a near-Earth object of the Amor group, that measures approximately 1.5 kilometers in diameter.

    3199 Nefertiti, provisional designation 1982 RA, is a rare-type asteroid, classified as near-Earth object of the Amor group of asteroids, approximately 2.2 kilometers in diameter. It was discovered on 13 September 1982, by American astronomer couple Carolyn and Eugene Shoemaker at Palomar Observatory, California, United States.

    2201 Oljato, provisional designation 1947 XC, is a stony and extremely eccentric active asteroid and sizable near-Earth object of the Apollo group, approximately 2 kilometers in diameter. It has an Earth minimum orbit intersection distance of 0.0031 AU (460 thousand km) and is associated with the Beta Taurids daytime meteor shower.

    3288 Seleucus, provisional designation 1982 DV, is a rare-type stony asteroid, classified as near-Earth object of the Amor group of asteroids, approximately 2.5 kilometers in diameter. It was discovered on 28 February 1982, by German astronomer Hans-Emil Schuster at ESO's La Silla Observatory site in northern Chile. It was named after the Hellenistic general and Seleucid ruler Seleucus I Nicator.

    1915 Quetzálcoatl, provisional designation 1953 EA, is a very eccentric, stony asteroid classified as near-Earth object, about half a kilometer in diameter. It was discovered on 9 March 1953, by American astronomer Albert George Wilson at Palomar Observatory, California. It was named for Quetzalcoatl from Aztec mythology.

    <span class="nowrap">(66063) 1998 RO<sub>1</sub></span> Stony near-Earth object of the Aten group

    (66063) 1998 RO1 is a stony near-Earth object of the Aten group on a highly-eccentric orbit. The synchronous binary system measures approximately 800 meters (0.50 miles) in diameter. It was discovered by astronomers of the Lincoln Near-Earth Asteroid Research at the Lincoln Laboratory's Experimental Test Site near Socorro, New Mexico, on 14 September 1998.

    References

    1. 1 2 3 4 5 6 7 8 9 10 11 "JPL Small-Body Database Browser: 2100 Ra-Shalom (1978 RA)" (2016-10-26 last obs.). Jet Propulsion Laboratory . Retrieved 3 July 2017.
    2. "shalom". Dictionary.com Unabridged (Online). n.d.
    3. 1 2 3 Schmadel, Lutz D. (2007). "(2100) Ra-Shalom". Dictionary of Minor Planet Names. Springer Berlin Heidelberg. p. 170. doi:10.1007/978-3-540-29925-7_2101. ISBN   978-3-540-00238-3.
    4. 1 2 "2100 Ra-Shalom (1978 RA)". Minor Planet Center. Retrieved 7 December 2016.
    5. 1 2 3 4 Usui, Fumihiko; Kuroda, Daisuke; Müller, Thomas G.; Hasegawa, Sunao; Ishiguro, Masateru; Ootsubo, Takafumi; et al. (October 2011). "Asteroid Catalog Using Akari: AKARI/IRC Mid-Infrared Asteroid Survey". Publications of the Astronomical Society of Japan. 63 (5): 1117–1138. Bibcode:2011PASJ...63.1117U. doi:10.1093/pasj/63.5.1117. (online, AcuA catalog p. 153)
    6. 1 2 3 4 Harris, Alan W. (February 1998). "A Thermal Model for Near-Earth Asteroids". Icarus. 131 (2): 291–301. Bibcode:1998Icar..131..291H. doi:10.1006/icar.1997.5865 . Retrieved 11 January 2016.
    7. 1 2 3 Trilling, D. E.; Mueller, M.; Hora, J. L.; Harris, A. W.; Bhattacharya, B.; Bottke, W. F.; et al. (September 2010). "ExploreNEOs. I. Description and First Results from the Warm Spitzer Near-Earth Object Survey". The Astronomical Journal. 140 (3): 770–784. Bibcode:2010AJ....140..770T. doi: 10.1088/0004-6256/140/3/770 .
    8. 1 2 3 Harris, A. W.; Mommert, M.; Hora, J. L.; Mueller, M.; Trilling, D. E.; Bhattacharya, B.; et al. (March 2011). "ExploreNEOs. II. The Accuracy of the Warm Spitzer Near-Earth Object Survey". The Astronomical Journal. 141 (3): 10. Bibcode:2011AJ....141...75H. doi: 10.1088/0004-6256/141/3/75 .
    9. 1 2 3 4 5 6 7 Shepard, Michael K.; Clark, Beth Ellen; Nolan, Michael C.; Benner, Lance A. M.; Ostro, Steven J.; Giorgini, Jon D.; et al. (January 2008). "Multi-wavelength observations of Asteroid 2100 Ra-Shalom". Icarus. 193 (1): 20–38. Bibcode:2008Icar..193...20S. CiteSeerX   10.1.1.462.876 . doi:10.1016/j.icarus.2007.09.006 . Retrieved 11 January 2016.
    10. 1 2 3 4 Harris, Alan W.; Davies, John K.; Green, Simon F. (October 1998). "Thermal Infrared Spectrophotometry of the Near-Earth Asteroids 2100 Ra-Shalom and 1991 EE". Icarus. 135 (2): 441–450. Bibcode:1998Icar..135..441H. doi:10.1006/icar.1998.6002 . Retrieved 11 January 2016.
    11. 1 2 3 4 Delbó, Marco; Harris, Alan W.; Binzel, Richard P.; Pravec, Petr; Davies, John K. (November 2003). "Keck observations of near-Earth asteroids in the thermal infrared". Icarus. 166 (1): 116–130. Bibcode:2003Icar..166..116D. doi:10.1016/j.icarus.2003.07.002 . Retrieved 11 January 2016.
    12. 1 2 3 4 5 "LCDB Data for (2100) Ra-Shalom". Asteroid Lightcurve Database (LCDB). Retrieved 7 December 2016.
    13. 1 2 3 Delbo, Marco; Walsh, Kevin; Mueller, Michael; Harris, Alan W.; Howell, Ellen S. (March 2011). "The cool surfaces of binary near-Earth asteroids". Icarus. 212 (1): 138–148. Bibcode:2011Icar..212..138D. doi:10.1016/j.icarus.2010.12.011. S2CID   122586509 . Retrieved 11 January 2016.
    14. 1 2 3 Harris, A. W.; Young, J. W.; Dockweiler, Thor; Gibson, J.; Poutanen, M.; Bowell, E. (January 1992). "Asteroid lightcurve observations from 1981". Icarus. 95 (1): 115–147.ResearchsupportedbyLowellObservatoryEndowmentandNASA. Bibcode:1992Icar...95..115H. doi:10.1016/0019-1035(92)90195-D. ISSN   0019-1035 . Retrieved 11 January 2016.
    15. 1 2 3 Pravec, Petr; Wolf, Marek; Sarounová, Lenka (November 1998). "Lightcurves of 26 Near-Earth Asteroids". Icarus. 136 (1): 124–153. Bibcode:1998Icar..136..124P. doi:10.1006/icar.1998.5993 . Retrieved 11 January 2016.
    16. 1 2 Kaasalainen, Mikko; Pravec, Petr; Krugly, Yurij N.; Sarounová, Lenka; Torppa, Johanna; Virtanen, Jenni; et al. (January 2004). "Photometry and models of eight near-Earth asteroids". Icarus. 167 (1): 178–196. Bibcode:2004Icar..167..178K. doi:10.1016/j.icarus.2003.09.012 . Retrieved 11 January 2016.
    17. 1 2 Durech, J.; Vokrouhlický, D.; Baransky, A. R.; Breiter, S.; Burkhonov, O. A.; Cooney, W.; et al. (November 2012). "Analysis of the rotation period of asteroids (1865) Cerberus, (2100) Ra-Shalom, and (3103) Eger - search for the YORP effect". Astronomy and Astrophysics. 547: 9. arXiv: 1210.2219 . Bibcode:2012A&A...547A..10D. doi:10.1051/0004-6361/201219396. S2CID   54496050 . Retrieved 11 January 2016.
    18. 1 2 Warner, Brian D. (January 2017). "Near-Earth Asteroid Lightcurve Analysis at CS3-Palmer Divide Station: 2016 July-September". The Minor Planet Bulletin. 44 (1): 22–36. Bibcode:2017MPBu...44...22W. ISSN   1052-8091. PMC   7243971 . PMID   32455389 . Retrieved 11 June 2017.
    19. Thomas, C. A.; Trilling, D. E.; Emery, J. P.; Mueller, M.; Hora, J. L.; Benner, L. A. M.; et al. (September 2011). "ExploreNEOs. V. Average Albedo by Taxonomic Complex in the Near-Earth Asteroid Population". The Astronomical Journal. 142 (3): 12. Bibcode:2011AJ....142...85T. doi: 10.1088/0004-6256/142/3/85 .
    20. 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 . Retrieved 7 December 2016.
    21. "JPL Close-Approach Data: 2100 Ra-Shalom (1978 RA)" (2013-10-25 last obs). Retrieved 5 May 2009.
    22. 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. ISBN   978-3-642-01964-7.
    23. Ostro, S. J.; Harris, A. W.; Campbell, D. B.; Shapiro, I. I.; Young, J. W. (November 1984). "Radar and photoelectric observations of asteroid 2100 Ra-Shalom". Icarus. 60 (2): 391–403. Bibcode:1984Icar...60..391O. doi:10.1016/0019-1035(84)90198-2. ISSN   0019-1035 . Retrieved 11 January 2016.