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11066 Sigurd (provisional designation 1992 CC₁) is a stony contact binary asteroid classified as near-Earth object of the Apollo group of asteroids, approximately 2.5 kilometers in diameter.

It was discovered on 9 February 1992 by American astronomer couple Carolyn and Eugene Shoemaker at Palomar Observatory, California, and named after Sigurd, a hero from Norse mythology.

Orbit and classification

Sigurd orbits the Sun in the inner main-belt at a distance of 0.9–1.9 AU once every 1 years and 8 months (600 days). Its orbit has an eccentricity of 0.38 and an inclination of 37° with respect to the ecliptic. A first precovery was taken at the Australian Siding Spring Observatory in 1978, and it was identified as 1987 GE at Palomar in 1987. Both observations remained unused. The body's observation arc begins with its official discovery observation at Palomar in 1992.

It has an Earth minimum orbital intersection distance of 0.1183 AU (17,700,000 km), which corresponds to 46.1 lunar distances.

Physical characteristics

In the SMASS taxonomy, Sigurd is a relatively rare K-type asteroid, which fall into the broader stony S-complex. It has also been grouped into the common S-type asteroid. The ExploreNEOs Warm Spitzer program, using the NASA Infrared Telescope Facility on Mauna Kea Observatory in Hawaii, classifies Sigurd as a Sr-type, which transitions to the R-type asteroids.

Contact binary

Radiometric observations at Arecibo Observatory revealed that Sigurd is a contact binary, composed of two lobes in contact with each other. The more or less ellipsoidal lobes are elongated and joined on their long axis. The body has an axial tilt of 50° to 130°. The observing astronomers also note, that more than 10% of all larger (> 200 meters) near-Earth objects observed by radar are such contact binaries.

Photometry

Rotational lightcurves obtained from photometric observations by Petr Pravec, Brian Warner and by a group of German and Ukrainian astronomers, gave a well-defined rotation period of 8.4958 to 8.51 hours. The analysis of the constructed lightcurves also gave a high brightness amplitude between 0.97 and 1.15 magnitude, which is indicative that Sigurd has a non-spheroidal shape (U=3/3/3).

Diameter and albedo

According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Sigurd measures between 2.10 and 2.778 kilometers in diameter and its surface has an albedo of 0.190 and 0.29, respectively. Observations by the ExploreNEOs survey give a higher albedo of 0.38. The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.18 and calculates a diameter of 2.86 kilometers with an absolute magnitude of 15.2, while radiometric observations of Sigurd gave an maximum dimensions of 4.2 kilometers.

Naming

This minor planet was named after Sigurd, a legendary hero in Norse mythology. In the Völsunga saga, Sigurd rides through a ring of fire to awaken the shieldmaiden Brynhild (123 Brunhild), and later dies in a fight with Odin (3989 Odin). Sigurd is also known as the dragon-slayer Siegfried in the German poem The Song of the Nibelungs. The approved naming citation was published by the Minor Planet Center on 23 May 2000 (M.P.C. 40706).

References

1. ^ "JPL Small-Body Database Browser: 11066 Sigurd (1992 CC1)" (2017-06-22 last obs.). Jet Propulsion Laboratory. Retrieved 5 July 2017.
2. ^ Schmadel, Lutz D. (2007). "(11066) Sigurd". Dictionary of Minor Planet Names – (11066) Sigurd. Springer Berlin Heidelberg. p. 751. doi:10.1007/978-3-540-29925-7_8204. ISBN 978-3-540-00238-3.
3. ^ "11066 Sigurd (1992 CC1)". Minor Planet Center. Retrieved 5 April 2017.
4. ^ "LCDB Data for (11066) Sigurd". Asteroid Lightcurve Database (LCDB). Retrieved 5 April 2017.
5. ^ Nugent, C. R.; Mainzer, A.; Bauer, J.; Cutri, R. M.; Kramer, E. A.; Grav, T.; et al. (September 2016). "NEOWISE Reactivation Mission Year Two: Asteroid Diameters and Albedos". The Astronomical Journal. 152 (3): 12. arXiv:1606.08923. Bibcode:2016AJ....152...63N. doi:10.3847/0004-6256/152/3/63.
6. ^ Mainzer, A.; Grav, T.; Masiero, J.; Hand, E.; Bauer, J.; Tholen, D.; et al. (November 2011). "NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results". The Astrophysical Journal. 741 (2): 25. arXiv:1109.6407. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90. S2CID 35447010.
7. ^ Mainzer, A.; Grav, T.; Bauer, J.; Masiero, J.; McMillan, R. S.; Cutri, R. M.; et al. (December 2011). "NEOWISE Observations of Near-Earth Objects: Preliminary Results". The Astrophysical Journal. 743 (2): 17. arXiv:1109.6400. Bibcode:2011ApJ...743..156M. doi:10.1088/0004-637X/743/2/156. S2CID 239991. Retrieved 5 April 2017.
8. ^ 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 5 April 2017.
9. ^ Krugly, Yu. N.; Belskaya, I. N.; Shevchenko, V. G.; Chiorny, V. G.; Velichko, F. P.; Mottola, S.; et al. (August 2002). "The Near-Earth Objects Follow-up Program. IV. CCD Photometry in 1996-1999". Icarus. 158 (2): 294–304. Bibcode:2002Icar..158..294K. doi:10.1006/icar.2002.6884. Retrieved 5 April 2017.
10. ^ Warner, Brian D. (July 2015). "Near-Earth Asteroid Lightcurve Analysis at CS3-Palmer Divide Station: 2015 January - March". The Minor Planet Bulletin. 42 (3): 172–183. Bibcode:2015MPBu...42..172W. ISSN 1052-8091. PMC 7244166. PMID 32455355.
11. 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.
12. ^ Thomas, Cristina A.; Emery, Joshua P.; Trilling, David E.; Delbó, Marco; Hora, Joseph L.; Mueller, Michael (January 2014). "Physical characterization of Warm Spitzer-observed near-Earth objects". Icarus. 228: 217–246. arXiv:1310.2000. Bibcode:2014Icar..228..217T. doi:10.1016/j.icarus.2013.10.004. hdl:2060/20140012047. S2CID 119278697. Retrieved 5 April 2017.
13. ^ Carry, B.; Solano, E.; Eggl, S.; DeMeo, F. E. (April 2016). "Spectral properties of near-Earth and Mars-crossing asteroids using Sloan photometry". Icarus. 268: 340–354. arXiv:1601.02087. Bibcode:2016Icar..268..340C. doi:10.1016/j.icarus.2015.12.047. S2CID 119258489. Retrieved 5 April 2017.
14. Veres, 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. S2CID 53493339. Retrieved 5 April 2017.
15. ^ Busch, Michael W.; Ostro, S. J.; Benner, L. A.; Brozovic, M.; Magri, C.; Scheeres, D. J.; et al. (October 2012). "Radar Imaging Of 11066 Sigurd, 2000 YF29, And 2004 XL14 And The Obliquity Distribution Of Contact Binary Near-Earth Asteroids". American Astronomical Society. 44: 302.05. Bibcode:2012DPS....4430205B. Retrieved 5 April 2017.
16. "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 5 April 2017.

External links

• IAUC 5459 (discovery 1992 CC₁), Central Bureau for Astronomical Telegrams, 27 February 1992
• Contact Binary Asteroids and Comets, Robert Johnston, list at jonstonsarchive.net, 25 March 2017
• Binary and Ternary near-Earth Asteroids detected by radar, Lance A. M. Benner, ASA/JPL Asteroid Radar Research
• (11066) Sigurd at NEODyS-2
• Asteroid Lightcurve Database (LCDB), query form (info Archived 16 December 2017 at the Wayback Machine)
• Dictionary of Minor Planet Names, Google books
• Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
• 11066 Sigurd at NeoDyS-2, Near Earth Objects—Dynamic Site
  • Ephemerides · Observation prediction · Orbital info · MOID · Proper elements · Observational info · Close approaches · Physical info · Orbit animation
• 11066 Sigurd at ESA–space situational awareness
  • Ephemerides · Observations · Orbit · Physical properties · Summary
• 11066 Sigurd at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit viewer · Orbit parameters · Physical parameters

• Minor planet object articles (numbered)
• Apollo asteroids
• Discoveries by Eugene Merle Shoemaker
• Discoveries by Carolyn S. Shoemaker
• Named minor planets
• Contact binary (small Solar System body)
• Radar-imaged asteroids
• K-type asteroids (SMASS)
• Astronomical objects discovered in 1992