65 Cybele

Outer main-belt asteroid

65 Cybele

Discovery [1][2]
Discovered by| E. W. Tempel
Discovery site| Marseille Obs.
Discovery date| 8 March 1861
Designations

MPC designation

| (65) Cybele
Pronunciation| /ˈsɪbəliː/[3]

Named after

| Cybele [4]
(Hellenistic deity)

Alternative designations

| 1949 YQ

Minor planet category

| main belt * (outer)[1]
Cybele[5]
Adjectives| Cybelean /ˌsɪbəˈliːən/, rarely Cybelian /sɪˈbɛliən/
Orbital characteristics
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc| 155.98 yr (56,971 d)
Aphelion| 3.8102 AU
Perihelion| 3.0464 AU

Semi-major axis

| 3.4283 AU
Eccentricity| 0.1114

Orbital period (sidereal)

| 6.35 yr (2,319 days)

Mean anomaly

| 168.06°

Mean motion

| 0° 9m 19.08s / day
Inclination| 3.5627°

Longitude of ascending node

| 155.63°

Argument of perihelion

| 102.37°
Physical characteristics
Dimensions| 297 km × 291 km × 213 km[6]

Mean diameter

| 263±3 km[6]
Mass| est. (14.8±1.8)×1018 kg[6]

Mean density

| 1.55±0.19 g/cm3[6]

Synodic rotation period

| 3.98704 h[7]
4.036 h[8]
4.04 h[9]
4.04052 h[10][11]
6.07 h[12]
6.07 h[13]
6.08±0.05 h[14]
6.081±0.001 h[a]
6.0814±0.0001 h[15]
6.081434±0.000005 h[16]
6.082±0.001 h[17]

Geometric albedo

| 0.044[18]
0.050±0.005[19]
0.06±0.03[20]
0.06±0.04[21]
0.0706±0.003[22][23]

Spectral type

| Tholen = P [1]
SMASS = Xc [1] * X [23]
B–V = 0.690[1]
U–B = 0.271[1]
V–R = 0.400±0.007[24]

Apparent magnitude

| 10.67 to 13.64

Absolute magnitude (H)

| 6.58±0.06[24] * 6.62[1][22][23][21][18] * 6.88±0.26[25] * 6.95[20]

Cybele, minor planet designation 65 Cybele, is one of the largest asteroids in the Solar System. It is located in the outer asteroid belt. It is thought to be a remnant primordial body.[6] It gives its name to the Cybele group of asteroids[5] that orbit outward from the Sun from the 2:1 orbital resonance with Jupiter. The X-type asteroid has a relatively short rotation period of 6.0814 hours. It was discovered by Wilhelm Tempel in 1861, and named after Cybele, the earth goddess.

## Discovery and naming[edit]

Cybele was discovered on 8 March 1861, by German astronomer Wilhelm Tempel from the Marseilles Observatory in southeastern France.[2] A minor controversy arose from its naming process. Tempel had awarded the honour of naming the asteroid to Carl August von Steinheil in recognition of his achievements in telescope production. Von Steinheil elected to name it "Maximiliana" after the reigning monarch Maximilian II of Bavaria. At the time, asteroids were conventionally given classical names, and a number of astronomers protested this contemporary appellation. The name Cybele was chosen instead, referring to the Phrygian goddess of the earth.[4] (The previously discovered 45 Eugenia, 54 Alexandra, and 64 Angelina had nevertheless also been given non-classical names; 64 Angelina had also been discovered by Tempel, but its name stood despite similar protests.)

## Physical characteristics[edit]

The first Cybelian stellar occultation was observed on 17 October 1979, in the Soviet Union. The asteroid appeared to have an irregular shape, with the longest chord being measured as 245 km, closely matching results determined by the IRAS satellite in 1983 (see below). During the same 1979 occultation, a hint of a possible 11 km wide minor-planet moon at 917 km distance was detected,[26] but has since never been corroborated. As of 2017, neither the Asteroid Lightcurve Data Base nor Johnston's archive consider Cybele to be a binary asteroid.[23][27]

### Diameter estimates[edit]

Mean-diameter estimates for Cybele range between 218.56 and 300.54 kilometers. According to observations by the Infrared Astronomical Satellite IRAS in 1983, the asteroid has a diameter of 237.26 km.[22] The NEOWISE mission of NASA's Wide-field Infrared Survey Explorer gave a diameter of 218.56 and 276.58 km.[20][21] The largest estimates of 300.54 km is from the Japanese Akari satellite.[18] In 2004, Müller estimated Cybele using thermophysical modelling (TPM) to have dimensions of 302 × 290 × 232 km, which corresponds to a mean-diameter of 273.0 km.[19]

## Spectrum[edit]

Examination of the asteroid's infrared spectrum shows an absorption feature that is similar to the one present in the spectrum of 24 Themis. This can be explained by the presence of water ice. The asteroid may be covered in a layer of fine silicate dust mixed with small amounts of water-ice and organic solids.[28]

## Recent occultations[edit]

On August 24, 2008, Cybele occulted 2UCAC 24389317, a 12.7-magnitude star in the constellation Ophiuchus which showed a long axis of at least 294 km.[29] On 11 October 2009, Cybele occulted a 13.4-magnitude star in the constellation Aquarius.[30]

## Notes[edit]

1. ^ Pilcher (2014m). Rotation period for (65) Cybele: 6.081±0.001 hours with a brightness amplitude of 0.03±0.01 mag. Quality Code of 3-. Summary figures at the LCDB; not available as 2014MPBu...41..250F at ADS

## References[edit]

1. ^ a b c d e f g "JPL Small-Body Database Browser: 65 Cybele" (2017-11-26 last obs.). Jet Propulsion Laboratory. Retrieved 22 December 2017.
2. ^ a b "(65) Cybele". Minor Planet Center. Retrieved 21 April 2017.
3. ^ Noah Webster (1884) A Practical Dictionary of the English Language
4. ^ a b Schmadel, Lutz D. (2007). "(65) Cybele". Dictionary of Minor Planet Names. Springer Berlin Heidelberg. p. 21\. doi:10.1007/978-3-540-29925-7_66. ISBN 978-3-540-00238-3.
5. ^ a b Linda T. Elkins-Tanton - Asteroids, Meteorites, and Comets (2010) - Page 96 (Google Books)
6. ^ a b c d e Marsset et al. (2022) The equilibrium shape of (65) Cybele: primordial or relic of a large impact?
7. ^ Drummond, J. D.; Weidenschilling, S. J.; Chapman, C. R.; Davis, D. R. (October 1988). "Photometric geodesy of main-belt asteroids. II - Analysis of lightcurves for poles, periods, and shapes". Icarus. 76 (1): 19–77. Bibcode:1988Icar...76...19D. doi:10.1016/0019-1035(88)90139-X. ISSN 0019-1035. Retrieved 22 December 2017.
8. ^ Shevchenko, V. G.; Chiorny, V. G.; Kalashnikov, A. V.; Krugly, Yu. N.; Mohamed, R. A.; Velichko, F. P. (February 1996). "Magnitude-phase dependences for three asteroids". Astronomy and Astrophysics Supplement. 115: 475–479. Bibcode:1996A&AS..115..475S. Retrieved 22 December 2017.
9. ^ Hutton, R. G. (September 1990). "V+B Photoelectric Photometry of Asteroids 65 Cybele and 216 Kleopatra". The Minor Planet Bulletin. 17: 34. Bibcode:1990MPBu...17...34H. Retrieved 22 December 2017.
10. ^ De Angelis, G. (May 1995). "Asteroid spin, pole and shape determinations". Planetary and Space Science. 43 (5): 649–682. Bibcode:1995P&SS...43..649D. doi:10.1016/0032-0633(94)00151-G. Retrieved 22 December 2017.
11. ^ Drummond, J. D.; Weidenschilling, S. J.; Chapman, C. R.; Davis, D. R. (January 1991). "Photometric geodesy of main-belt asteroids. IV - an updated analysis of lightcurves for poles, periods, and shapes". Icarus. 89 (1): 44–64. Bibcode:1991Icar...89...44D. doi:10.1016/0019-1035(91)90086-9. ISSN 0019-1035. Retrieved 22 December 2017.
12. ^ Weidenschilling, S. J.; Chapman, C. R.; Davis, D. R.; Greenberg, R.; Levy, D. H.; Vail, S. (May 1987). "Photometric geodesy of main-belt asteroids. I - Lightcurves of 26 large, rapid rotators". Icarus. 70 (2): 191–245. Bibcode:1987Icar...70..191W. doi:10.1016/0019-1035(87)90131-X. ISSN 0019-1035. Retrieved 22 December 2017.
13. ^ Schober, H. J.; Scaltriti, F.; Zappala, V.; Harris, A. W. (November 1980). "The remaining large minor planets with unknown rotational properties - 31 Euphrosyne and 65 Cybele". Astronomy and Astrophysics. 91 (1–2): 1–6.ResearchsupportedbytheOesterreichischerFondszurFoerderungderWissenschaftlichenForschung. Bibcode:1980A&A....91....1S. Retrieved 22 December 2017.
14. ^ Behrend, Raoul. "Asteroids and comets rotation curves – (65) Cybele". Geneva Observatory. Retrieved 22 December 2017.
15. ^ Pilcher, Frederick (April 2012). "Rotation Period Determinations for 31 Euphrosyne, 65 Cybele, 154 Bertha 177 Irma, 200 Dynamene, 724 Hapag, 880 Herba, and 1470 Carla". The Minor Planet Bulletin. 39 (2): 57–60. Bibcode:2012MPBu...39...57P. ISSN 1052-8091. Retrieved 22 December 2017.
16. ^ Franco, Lorenzo; Pilcher, Frederick (July 2015). "Lightcurve Inversion for 65 Cybele". The Minor Planet Bulletin. 42 (3): 204–206. Bibcode:2015MPBu...42..204F. ISSN 1052-8091. Retrieved 22 December 2017.
17. ^ Pilcher, Frederick (January 2010). "Rotation Period Determination for 65 Cybele". The Minor Planet Bulletin. 37 (1): 8. Bibcode:2010MPBu...37....8P. ISSN 1052-8091. Retrieved 22 December 2017.
18. ^ a b c 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. Retrieved 17 October 2019. (online, AcuA catalog p. 153)
19. ^ a b Müller, T. G.; Blommaert, J. A. D. L. (April 2004). "65 Cybele in the thermal infrared: Multiple observations and thermophysical analysis". Astronomy and Astrophysics. 418: 347–356. arXiv:astro-ph/0401458. Bibcode:2004A&A...418..347M. doi:10.1051/0004-6361:20040025. S2CID 18524619. Retrieved 21 April 2017.
20. ^ a b c 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.
21. ^ a b c Nugent, C. R.; Mainzer, A.; Masiero, J.; Bauer, J.; Cutri, R. M.; Grav, T.; et al. (December 2015). "NEOWISE Reactivation Mission Year One: Preliminary Asteroid Diameters and Albedos". The Astrophysical Journal. 814 (2): 13. arXiv:1509.02522. Bibcode:2015ApJ...814..117N. doi:10.1088/0004-637X/814/2/117. S2CID 9341381. Retrieved 19 October 2017.
22. ^ a b c Tedesco, E. F.; Noah, P. V.; Noah, M.; Price, S. D. (October 2004). "IRAS Minor Planet Survey V6.0". NASA Planetary Data System. 12: IRAS-A-FPA-3-RDR-IMPS-V6.0. Bibcode:2004PDSS...12.....T. Retrieved 22 October 2019.
23. ^ a b c d "LCDB Data for (65) Cybele". Asteroid Lightcurve Database (LCDB). Retrieved 21 April 2017.
24. ^ a b Warner, Brian D. (December 2007). "Initial Results of a Dedicated H-G Project". The Minor Planet Bulletin. 34 (4): 113–119. Bibcode:2007MPBu...34..113W. ISSN 1052-8091. Retrieved 22 December 2017.
25. ^ 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 19 October 2017.
26. ^ "IAUC 3439: 1979l; Occn OF AGK3 +19 599 BY (65)". IAU – Central Bureau for Astronomical Telegrams. 4 January 1980. Retrieved 21 April 2017.
27. ^ Johnston, Robert (25 March 2017). "Asteroids with Satellites". johnstonsarchive.net. Retrieved 21 April 2017.
28. ^ Licandro, J.; Campins, H.; Kelley, M.; Hargrove, K.; Pinilla-Alonso, N.; Cruikshank, D.; et al. (January 2011). "(65) Cybele: detection of small silicate grains, water-ice, and organics". Astronomy and Astrophysics. 525: 7. Bibcode:2011A&A...525A..34L. doi:10.1051/0004-6361/201015339.
29. ^ IOTA. "(65) Cybele 2008 Aug 24 profile". Archived from the original on 3 March 2012. Retrieved 2 December 2010.
30. ^ Steve Preston. "(65) Cybele / 2UCAC 28838190 event on 2009 Oct 11, 01:30 UT". Retrieved 21 September 2009.[permanent dead link]

## External links[edit]

* 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 – (17) Thetis at Observatoire de Genève, Raoul Behrend
* Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
* 65 Cybele at AstDyS-2, Asteroids—Dynamic Site
* Ephemeris * Observation prediction * Orbital info * Proper elements * Observational info
* 65 Cybele at the JPL Small-Body Database
* Close approach * Discovery * Ephemeris * Orbit diagram * Orbital elements * Physical parameters

* v
* t
* e

Minor planets navigator

* 64 Angelina
* 65 Cybele
* 66 Maja

* v
* t
* e

Large asteroids (over 200 km in diameter)

Asteroids over 900 km|

Ceres (a dwarf planet)

Asteroids between 500 and 600 km|

* Vesta
* Pallas

Asteroids between 300 and 500 km|

* Hygiea
* Interamnia
* Europa

Asteroids between 200 and 300 km|

* Davida
* Euphrosyne
* Patientia
* Sylvia
* Juno
* Cybele
* Eunomia
* Thisbe
* Psyche
* Hektor
* Bamberga
* Doris
* Ursula
* Camilla
* Aurora
* Daphne
* Egeria
* Eugenia
* Fortuna
* Iris

Authority control databases |

* JPL SBDB
* MPC

|

*[v]: View this template
*[t]: Discuss this template
*[e]: Edit this template