1866 Sisyphus

1866 Sisyphus

Discovery[1]
Discovered by	P. Wild
Discovery site	Zimmerwald Obs.
Discovery date	5 December 1972
Designations
MPC designation	(1866) Sisyphus
Pronunciation	/ˈsɪsɪfəs/
Named after	Σίσυφος Sīsyphos (Greek mythology)[2]
Alternative designations	1972 XA
Minor planet category	Apollo NEO[1][3] Mars-crosser
Adjectives	Sysiphean /sɪsɪˈfiːən/,[4] Sisyphian /sɪˈsɪfiən/[5]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	61.55 yr (22,482 days)
Earliest precovery date	26 January 1955
Aphelion	2.913 AU (435.8 Gm)
Perihelion	0.8747312 AU (130.85792 Gm)
Semi-major axis	1.8936992 AU (283.29337 Gm)
Eccentricity	0.5386
Orbital period (sidereal)	2.61 yr (952 days)
Mean anomaly	85.918°
Mean motion	0° 22^m 41.88^s / day
Inclination	41.202°
Longitude of ascending node	63.498°
Argument of perihelion	293.09°
Known satellites	1[a][6][7][8] (Orbital period of 27.16±0.05 h)
Earth MOID	0.1045 AU (15.63 Gm)
Mars MOID	0.1291 AU (19.31 Gm)
Physical characteristics
Dimensions	5.72±0.07 km[9] 6.597±0.189 km[10] 6.859 km[11] 6.86 km (taken)[12] 8 km[6][a] 8.48 km[13] 8.9 km[14]
Synodic rotation period	2.3909±0.0004 h[8] 2.400 h[15] 2.4 h[b] 2.401±0.001 h[7] 2.424±0.001 h[16] 2.7 h[17]
Geometric albedo	0.14[14] 0.15[13] 0.19±0.07[18] 0.255±0.049[10] 0.360±0.010[9] 0.3719[11]
Spectral type	SMASS = S[1] S[19]
Apparent magnitude	9.0 (discovery) 9.3 (2071 close approach)
Absolute magnitude (H)	11.7±0.2 (R)[b] 12.4[1] 12.51±0.149[11][12] 13.0[9][10][13]

1866 Sisyphus /ˈsɪsɪfəs/ is a binary^[8] stony asteroid, near-Earth object and the largest member of the Apollo group, approximately 7 kilometers in diameter.

It was discovered on 5 December 1972, by Swiss astronomer Paul Wild at Zimmerwald Observatory near Bern, Switzerland, and given the provisional designation 1972 XA. It was named after Sisyphus from Greek mythology.^[3][20]

Orbit and classification

This S-type asteroid (composed of rocky silicates) orbits the Sun in the inner main-belt at a distance of 0.9–2.9 AU once every 2 years and 7 months (952 days). Its orbit has an eccentricity of 0.54 and an inclination of 41° with respect to the ecliptic.^[1]

The Apollo asteroid has an Earth minimum orbit intersection distance of 0.1037 AU (15,500,000 km), which corresponds to 40.4 lunar distances.^[1] It will pass 0.11581 AU (17,325,000 km) from Earth on 24 November 2071,^[21] and will peak at roughly apparent magnitude 9.3 on 26 November 2071.^[22] When it was discovered it peaked at magnitude 9.0 on 25 November 1972. It is one of the brightest near-Earth asteroids.

Physical characteristics

In the SMASS classification, Sisyphus is a common stony S-type asteroid.^[1]

Binary system

In 1985, this object was detected with radar from the Arecibo Observatory at a distance of 0.25 AU. The measured radar cross-section was 8 square kilometers.^[6][a] During the radar observations, a small minor-planet moon was detected around Sisyphus, although its existence was not reported until December 2007. Robert Stephens confirmed that it is a suspected binary,^[7] and Brian Warner added additional weight to this conclusion, giving 27.16±0.05 hours as the satellite's orbital period, longer than the 25 hours previously reported by Stephens.^[8]

Diameter and albedo

With a measured mean diameter in the range of 5.7–8.9 kilometers, it is the largest of the Earth-crossing asteroids, comparable in size to the Chicxulub object whose impact contributed to the extinction of the dinosaurs.^[23] Larger near-Earth asteroids which are neither classified as Apollos nor Earth-crossers include 1036 Ganymed (32 km), 3552 Don Quixote (19 km), 433 Eros (17 km), and 4954 Eric (10.8 km).

Naming

This minor planet is named after Sisyphus from Greek mythology and refers to the cruel king of Ephyra, punished by being given the task of rolling a large stone up to a hill in the underworld, only to have it roll down again each time he neared the top.^[2] The official naming citation was published by the Minor Planet Center on 20 December 1974 (M.P.C. 3758).^[24]

Notes

1. Benner (1985), gives a diameter of 8 kilometer. Summary figures listed at LCDB
2. Pravec (1998web), gives a rotation period of 2.4 hours. Summary figures listed at LCDB

References

1. "JPL Small-Body Database Browser: 1866 Sisyphus (1972 XA)" (2016-08-15 last obs.). Jet Propulsion Laboratory. Retrieved 9 June 2017.
2. Schmadel, Lutz D. (2007). "(1866) Sisyphus". Dictionary of Minor Planet Names – (1866) Sisyphus. Springer Berlin Heidelberg. p. 150. doi:10.1007/978-3-540-29925-7_1867. ISBN 978-3-540-00238-3.
3. "1866 Sisyphus (1972 XA)". Minor Planet Center. Retrieved 12 December 2016.
4. "Sisyphean". Oxford English Dictionary (Online ed.). Oxford University Press. (Subscription or participating institution membership required.)
5. "Sisyphian". Oxford English Dictionary (Online ed.). Oxford University Press. (Subscription or participating institution membership required.)
6. Ostro, S. J.; Campbell, D. B.; Chandler, J. F.; Shapiro, I. I.; Hine, A. A.; Velez, R.; et al. (October 1991). "Asteroid radar astrometry". Astronomical Journal. 102: 1490–1502.ResearchsupportedbyNASA. Bibcode:1991AJ....102.1490O. doi:10.1086/115975. ISSN 0004-6256. Retrieved 12 December 2016.
7. Stephens, Robert D.; French, Linda, M.; Warner, Brian D.; Wasserman, Lawrence H. (October 2011). "The Curse of Sisyphus". The Minor Planet Bulletin. 38 (4): 212–213. Bibcode:2011MPBu...38..212S. ISSN 1052-8091. Retrieved 12 December 2016.
8. Warner, Brian D. (October 2016). "Near-Earth Asteroid Lightcurve Analysis at CS3-Palmer Divide Station: 2016 April-July". The Minor Planet Bulletin. 43 (4): 311–319. Bibcode:2016MPBu...43..311W. ISSN 1052-8091. Retrieved 12 December 2016.
9. 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)
10. 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.
11. 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 12 December 2016.
12. "LCDB Data for (1866) Sisyphus". Asteroid Lightcurve Database (LCDB). Retrieved 12 December 2016.
13. 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 12 December 2016.
14. 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. Retrieved 12 December 2016.
15. Schober, H. J.; Erikson, A.; Hahn, G.; Lagerkvist, C. I.; Oja, T. (November 1993). "Physical Studies of Asteroids. Part XXVI. Rotation and Photoelectric Photometry of Asteroids 323, 350, 582, 1021 and 1866". Astronomy and Astrophysics Supplement. 101 (3): 507. Bibcode:1993A&AS..101..499S. Retrieved 12 December 2016.
16. Behrend, Raoul. "Asteroids and comets rotation curves – (1866) Sisyphus". Geneva Observatory. Retrieved 12 December 2016.
17. Szabó, Gy. M.; Csák, B.; Sárneczky, K.; Kiss, L. L. (August 2001). "Photometric observations of 9 Near-Earth Objects". Astronomy and Astrophysics. 375: 285–292. arXiv:astro-ph/0106017. Bibcode:2001A&A...375..285S. doi:10.1051/0004-6361:20010813. Retrieved 12 December 2016.
18. Mainzer, A.; Grav, T.; Masiero, J.; Bauer, J.; Wright, E.; Cutri, R. M.; et al. (August 2011). "Thermal Model Calibration for Minor Planets Observed with Wide-field Infrared Survey Explorer/NEOWISE". The Astrophysical Journal. 736 (2): 9. Bibcode:2011ApJ...736..100M. CiteSeerX 10.1.1.472.4936. doi:10.1088/0004-637X/736/2/100. Retrieved 12 December 2016.
19. 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. Retrieved 12 December 2016.
20. NASA.gov
21. "JPL Close-Approach Data: 1866 Sisyphus (1972 XA)" (last observation: 2013-07-26). Retrieved 30 October 2013.
22. "(1866) Sisyphus Ephemerides for November 2071". NEODyS (Near Earth Objects – Dynamic Site). Retrieved 30 October 2013.
23. "JPL Small-Body Database Search Engine: asteroids and NEOs and H < 13 (mag)". JPL Solar System Dynamics. Retrieved 31 October 2013.
24. 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. Bibcode:2009dmpn.book.....S. doi:10.1007/978-3-642-01965-4. ISBN 978-3-642-01964-7.

External links

• Asteroid Hazards, Part 1: What Makes an Asteroid a Hazard? on YouTube (min. 6:04)
• Asteroid Lightcurve Database (LCDB), query form (info Archived 16 December 2017 at the Wayback Machine)
• Asteroids with Satellites, Robert Johnston, johnstonsarchive.net
• Dictionary of Minor Planet Names, Google books
• Asteroids and comets rotation curves, CdR – Observatoire de Geneve, Raoul Behrend
• 1866 Sisyphus at NeoDyS-2, Near Earth Objects—Dynamic Site
  • Ephemerides · Observation prediction · Orbital info · MOID · Proper elements · Observational info · Close approaches · Physical info · Orbit animation
• 1866 Sisyphus at ESA–space situational awareness
  • Ephemerides · Observations · Orbit · Physical properties · Summary
• 1866 Sisyphus at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit viewer · Orbit parameters · Physical parameters