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2324 Janice
Discovery  [1]
Discovered by E. F. Helin
S. J. Bus
Discovery site Palomar Obs.
Discovery date7 November 1978
Designations
(2324) Janice
Named after
Janice Cline  [1]
(Supporter at Caltech)
1978 VS4 · 1929 WH
1934 VR · 1949 ME
1961 UP · 1971 OC1
1975 EM2 · 1977 RY4
A911 MC
main-belt [1] [2] · ( outer)
background [3] · Themis [4] [5]
Orbital characteristics [2]
Epoch 23 March 2018 ( JD 2458200.5)
Uncertainty parameter 0
Observation arc83.28 yr (30,418 d)
Aphelion3.6382 AU
Perihelion2.5282 AU
3.0832 AU
Eccentricity0.1800
5.41 yr (1,977 d)
245.72 °
0° 10m 55.56s / day
Inclination0.3995°
315.66°
305.63°
Physical characteristics
Mean diameter
23.55  km (calculated) [4]
24.33±6.61 km [6]
24.44±1.22 km [7]
25.76±7.43 km [8]
28.463±0.354 km [9]
28.532±0.238 km [10]
28.9±15.91 km [11]
31.19±15.91 km [12]
23.2±0.1  h [11]
0.038±0.004 [10]
0.050±0.040 [12]
0.06±0.04 [6]
0.0601±0.0049 [9]
0.07±0.03 [8]
0.08 (assumed) [4]
0.093±0.010 [7]
C (assumed) [4]
11.30 [7] · 11.40 [8] [9] [12]
11.46±0.36 [13] · 11.5 [2] [4]
11.68 [6]

2324 Janice, provisional designation 1978 VS4, is a dark background asteroid from the outer regions of the asteroid belt, approximately 25 kilometers (16 miles) in diameter. It was discovered on 7 November 1978, by American astronomers Eleanor Helin and Schelte Bus at the Palomar Observatory in California. [1] The asteroid was named for Janice Cline at Caltech. The presumably C-type asteroid has a rotation period of 23.2 hours. [4]

Orbit and classification

Based on osculating Keplerian orbital elements, Janice is located in the region of the Themis family ( 602), a very large family of carbonaceous asteroids, named after 24 Themis. [4]

When applying the hierarchical clustering method to its proper orbital elements, the object is both a non- family asteroid of the main belt's background population (according to Nesvorný), [3] as well as a core member of the Themis family (according to Milani and Knežević). [5]

It orbits the Sun in the outer main-belt at a distance of 2.5–3.6  AU once every 5 years and 5 months (1,977 days; semi-major axis of 3.08 AU). Its orbit has an eccentricity of 0.18 and an inclination of 0 ° with respect to the ecliptic. [2] The body's observation arc begins with its first observation as A911 MC at Lowell Observatory in June 1911, more than 67 years prior to its official discovery observation at Palomar. [1]

Physical characteristics

Janice is a presumed carbonaceous C-type asteroid which is the overall spectral type of members of the Themis family ( 602). [4]

Rotation period

In October 2010, a rotational lightcurve of Janice was obtained from photometric observations by Gordon Gartrelle at the University of North Dakota Observatory in Grand Forks ( 730). Lightcurve analysis gave a tentative rotation period of 23.2 hours with a brightness amplitude of 0.19 magnitude ( U=2-). [11] As of 2018, no secure period has been obtained. [4]

Diameter and albedo

According to the surveys carried out by the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Janice measures between 24.33 and 31.19 kilometers in diameter and its surface has an albedo between 0.038 and 0.093. [6] [7] [8] [9] [10] [12]

The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.08 and calculates a diameter of 23.55 kilometers based on an absolute magnitude of 11.5. [4]

Naming

This minor planet was named after Janice Cline, who for many years has encouraged astrometric studies of minor planets at Caltech. [1] The official naming citation was published by the Minor Planet Center on 1 March 1981 ( M.P.C. 5850). [14]

References

  1. ^ a b c d e f "2324 Janice (1978 VS4)". Minor Planet Center. Retrieved 26 March 2018.
  2. ^ a b c d "JPL Small-Body Database Browser: 2324 Janice (1978 VS4)" (2018-02-25 last obs.). Jet Propulsion Laboratory. Retrieved 26 March 2018.
  3. ^ a b "Small Bodies Data Ferret". Nesvorny HCM Asteroid Families V3.0. Archived from the original on 2 August 2017. Retrieved 26 March 2018.
  4. ^ a b c d e f g h i j "LCDB Data for (2324) Janice". Asteroid Lightcurve Database (LCDB). Retrieved 26 March 2018.
  5. ^ a b "Asteroid 2324 Janice – Proper Elements". AstDyS-2, Asteroids – Dynamic Site. Retrieved 29 October 2019.
  6. ^ a b c d 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.
  7. ^ a b c d 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)
  8. ^ a b c d 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.
  9. ^ a b c d 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.
  10. ^ a b c Masiero, Joseph R.; Mainzer, A. K.; Grav, T.; Bauer, J. M.; Cutri, R. M.; Dailey, J.; et al. (November 2011). "Main Belt Asteroids with WISE/NEOWISE. I. Preliminary Albedos and Diameters". The Astrophysical Journal. 741 (2): 20. arXiv: 1109.4096. Bibcode: 2011ApJ...741...68M. doi: 10.1088/0004-637X/741/2/68. S2CID  118745497.
  11. ^ a b c Gartrelle, Gordon M. (April 2012). "Lightcurve Results for Eleven Asteroids". The Minor Planet Bulletin. 39 (2): 40–46. Bibcode: 2012MPBu...39...40G. ISSN  1052-8091.
  12. ^ a b c d Masiero, Joseph R.; Mainzer, A. K.; Grav, T.; Bauer, J. M.; Cutri, R. M.; Nugent, C.; et al. (November 2012). "Preliminary Analysis of WISE/NEOWISE 3-Band Cryogenic and Post-cryogenic Observations of Main Belt Asteroids". The Astrophysical Journal Letters. 759 (1): 5. arXiv: 1209.5794. Bibcode: 2012ApJ...759L...8M. doi: 10.1088/2041-8205/759/1/L8. S2CID  46350317.
  13. ^ 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.
  14. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 26 March 2018.

External links