22899 Alconrad

22899 Alconrad
Discovery [1]
Discovered by K. Korlević
M. Jurić
Discovery site Višnjan Obs.
Discovery date 11 October 1999
Designations
MPC designation 22899 Alconrad
Named after
 Albert R. Conrad
(astronomer, AO-expert)[2]
1999 TO14 · 1998 ML48
main-belt · Koronis [3]
Orbital characteristics [1]
Epoch 16 February 2017 (JD 2457800.5)
Uncertainty parameter 0
Observation arc 21.57 yr (7,877 days)
Aphelion 3.0789 AU
Perihelion 2.6099 AU
2.8444 AU
Eccentricity 0.0824
4.80 yr (1,752 days)
259.89°
0° 12m 19.8s / day
Inclination 2.8820°
136.00°
220.55°
Known satellites 1 [lower-alpha 1][4]
Physical characteristics
Dimensions 4.5 km[4]
4.94 km (calculated)[3]
5.682±0.471 km[5][6]
4.03±0.03 h[7]
5.0206±0.0029 h[8]
0.181±0.029[5][6]
0.21[4]
0.24 (assumed)[3]
S [3]
13.677±0.004 (R)[8]
13.7[3][5] · 13.8[1]
13.96±0.25[9]

    22899 Alconrad, provisional designation 1999 TO14, is a binary Koronian asteroid from the outer region of the asteroid belt, approximately 5 kilometers in diameter. It was discovered on 11 October 1999, by Croatian astronomers Korado Korlević and Mario Jurić at the Višnjan Observatory, Croatia.[2] When the asteroid moon S/2003 (22899) 1 was discovered in 2003, it was the smallest known binary system in the main-belt.[lower-alpha 1][4]

    The stony S-type asteroid belongs to the Koronis family, a group consisting of few hundred known bodies with nearly ecliptical orbits. It orbits the Sun at a distance of 2.6–3.1 AU once every 4 years and 10 months (1,752 days). Its orbit has an eccentricity of 0.08 and an inclination of 3° with respect to the ecliptic.[1] A precovery was taken by Steward Observatory's Spacewatch program in 1994, extending Alconrad's observation arc by 5 years prior to its discovery observation.[2]

    In December 2009, a rotational light-curve was obtained from photometric observations at the ground-based Wise Observatory in Mitzpe Ramon, Israel. The light-curve gave it a rotation period of 4.03±0.03 hours with a brightness variation of 0.19±0.03 in magnitude (U=2).[7] In October 2013, another observation in the R-band at the U.S Palomar Transient Factory derived a longer period of 5.0206±0.0029 with an ampliutude of 0.14 in magnitude (U=2).[8]

    According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Alconrad measures 5.7 kilometers in diameter and its surface has an albedo of 0.18,[5][6] while he Collaborative Asteroid Lightcurve Link assumes a standard albedo for members of the Koronis family of 0.24 and calculates a diameter of 4.9 kilometers.[3] In October 2003, when the asteroid moon S/2003 (22899) 1 was discovered by the researchers at Southwest Research Institute using the Hubble Space Telescope, they calculated a diameter of 4.5 kilometers for the primary, based on an assumed albedo of 0.21. The researchers also measured a large angular separation of 0".14 between Alconrad and its moon. This is equivalent to a distance of 170 kilometers,[4] or 182 kilometers, when using a/Rp ratio of 81.[7] Based on a difference in magnitude of 2.5, the satellite measures 1 to 1.5 kilometers in diameter.[4][7]

    The minor planet was named in honor of American astronomer Albert R. Conrad (b. 1953) who worked at various observatories in the United States. Expert in and developer of adaptive optics, he has studied the natural satellites of the Solar System for their shape and topography, and co-discovered many asteroid moons in the process.[2] Naming citation was published on 20 June 2016 (M.P.C. 100606).[10]

    References

    1. 1 2 IAUC No. 8232, S/2003 (22899) 1, 26 October 2003

      Reports the "discovery on July 26.6 UT, on six direct images (two sets of three images taken 20 min apart in time) made with the Hubble Space Telescope (+ ACS/HRC) in the F606W (600-nm broadband) filter, of a satellite of minor planet (22899) 1999 TO_14 (V about 18). The satellite is clearly separated in five ofthese images but streaked in a sixth due to pointing jitter. Trails of several background stars in successive images indicate that the target object is not a background binary star. On July 26.6545, the satellite was at separation 0".14 (projected separation 170 km) in p.a. 235 deg. Using the average albedo of the Koronis family (about 0.21), to which (22899) belongs, the size of the primary is estimated to be 4.5 km. The brightness difference is about 2.5 mag, giving an estimated diameter of the secondary of about 1.5 km. This then is the smallest main-belt asteroid known to be binary."

      reported by: W. J. Merline, Southwest Research Institute (SwRI); P. M. Tamblyn, Binary Astronomy and SwRI; C. R. Chapman, D. Nesvorny, and D. D. Durda, SwRI; C. Dumas, JPL; A. D. Storrs, Towson University; L. M. Close, University of A rizona; and F. Menard, Observatoire de Grenoble, France. Central Bureau for Astronomical Telegrams – IAUC 8232
    1. 1 2 3 4 "JPL Small-Body Database Browser: 22899 Alconrad (1999 TO14)" (2016-05-03 last obs.). Jet Propulsion Laboratory. Retrieved 3 December 2016.
    2. 1 2 3 4 "22899 Alconrad (1999 TO14)". Minor Planet Center. Retrieved 22 June 2016.
    3. 1 2 3 4 5 6 "LCDB Data for (22899) Alconrad". Asteroid Lightcurve Database (LCDB). Retrieved 22 June 2016.
    4. 1 2 3 4 5 6 Merline, W. J.; Tamblyn, P. M.; Chapman, C. R.; Nesvorny, D.; Durda, D. D.; Dumas, C.; et al. (October 2003). "S/2003 (22899) 1". IAU Circ. (8232). Bibcode:2003IAUC.8232....2M. Retrieved 22 June 2016.
    5. 1 2 3 4 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:1109.6407Freely accessible. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90. Retrieved 22 June 2016.
    6. 1 2 3 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:1109.4096Freely accessible. Bibcode:2011ApJ...741...68M. doi:10.1088/0004-637X/741/2/68. Retrieved 3 December 2016.
    7. 1 2 3 4 Polishook, D.; Brosch, N.; Prialnik, D. (March 2011). "Rotation periods of binary asteroids with large separations - Confronting the Escaping Ejecta Binaries model with observations". Icarus. 212 (1): 167–174. arXiv:1012.4810Freely accessible. Bibcode:2011Icar..212..167P. doi:10.1016/j.icarus.2010.12.020.
    8. 1 2 3 Waszczak, Adam; Chang, Chan-Kao; Ofek, Eran O.; Laher, Russ; Masci, Frank; Levitan, David; et al. (September 2015). "Asteroid Light Curves from the Palomar Transient Factory Survey: Rotation Periods and Phase Functions from Sparse Photometry". The Astronomical Journal. 150 (3): 35. arXiv:1504.04041Freely accessible. Bibcode:2015AJ....150...75W. doi:10.1088/0004-6256/150/3/75. Retrieved 22 June 2016.
    9. ↑ 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:1506.00762Freely accessible. Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007. Retrieved 22 June 2016.
    10. ↑ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 22 June 2016.

    External links

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