(5407) 1992 AX, provisional designation 1992 AX, is a stony asteroid and a synchronous binary Mars-crosser from the innermost region of the asteroid belt, approximately 3.6 kilometers (2.2 miles) in diameter. It was discovered on 4 January 1992, by Japanese astronomers Seiji Ueda and Hiroshi Kaneda at the Kushiro Observatory on Hokkaidō, Japan.[1] The S-type asteroid has a short rotation period of 2.5 hours.[4] Its sub-kilometer satellite was discovered in 1997.[5] As of 2018, the binary system has not been named.[1]

(5407) 1992 AX
Orbital diagram of 1992 AX
Discovery[1]
Discovered byS. Ueda
H. Kaneda
Discovery siteKushiro Obs.
Discovery date4 January 1992
Designations
(5407) 1992 AX
1992 AX · 1987 BH2
Mars crosser[1][2][3]
binary[4][5]
Orbital characteristics[2]
Epoch 27 April 2019 (JD 2458600.5)
Uncertainty parameter 0
Observation arc66.90 yr (24,434 d)
Aphelion2.3486 AU
Perihelion1.3279 AU
1.8383 AU
Eccentricity0.2776
2.49 yr (910 d)
263.87°
0° 23m 43.8s / day
Inclination11.390°
117.74°
108.78°
Known satellites1 (D: 780 m; P: 13.52 h)[4][5]
Earth MOID0.377 AU (147 LD)
Physical characteristics
2.78±0.55 km[6]
3.60±0.36 km[7]
3.8±0.4 km[8]
4.18±0.12 km[9]
2.5488 h[10][11]
0.199[8]
0.294[9]
0.376[7]
0.40[6]
SMASS = Sk[2] · S[12]
B–V = 0.690[10]
V–R = 0.500[10]
V–I = 0.840[10]
13.90[7][9]
14.0[1][2]
14.47[8][10]

Orbit and classification

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1992 AX a member of the Mars-crossing asteroids, a dynamically unstable group between the main belt and the near-Earth populations, crossing the orbit of Mars at 1.66 AU.[1][3] It orbits the Sun at a distance of 1.3–2.3 AU once every 2 years and 6 months (910 days; semi-major axis of 1.84 AU). Its orbit has an eccentricity of 0.28 and an inclination of 11° with respect to the ecliptic.[2]

The asteroid makes occasional close approaches to Mars. Its next close approach, on 22 January 2027, will bring it 11,260,000 km (0.0753 AU) from Mars.[2] The body's observation arc begins with a precovery taken at Palomar Observatory in November 1951, or more than 40 years prior to its official discovery observation at Kushiro.[1]

Naming

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This minor planet was numbered by the Minor Planet Center on 9 December 1992 (M.P.C. 21249).[13] As of 2018, it has not been named.[1]

Physical characteristics

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1992 AX has been characterized as a common, stony S-type asteroid.[12] In the SMASS taxonomy, it is an Sk-subtype, that transitions between the S and K-type asteroids.[2] The body's color indices of 0.690 (B–V), 0.500 (V–R) and 0.840 (V–I) were also determined.[10]

Lightcurves

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Rotation period

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Since 1997, several rotational lightcurves of 1992 AX have been obtained from photometric observations by Petr Pravec and collaborating astronomers. Best-rated lightcurve analysis gave a rotation period of 2.5488 hours with a consolidated brightness amplitude between 0.10 and 0.12 magnitude (U=2/3).[4][10][11] The results supersedes a tentative period determination of 3.6 hours by Marc Buie (U=1).[4]

Satellite

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During the observations in January 1997, it was also revealed that 1992 AX is a synchronous binary asteroid with a minor-planet moon in its orbit.[10] The satellite measures approximately 780 meters in diameter, or about 20% of its primary, and has an orbital period of 13.52 hours with an estimated semi-major axis of 5.8 kilometers for its very circular orbit.[5] Observations by Pravec in January and February 2012 confirmed the binary nature of this asteroid, as well as its rotational and orbital periods.[4] The satellite's provisional designation is S/1997 (5407) 1.

Diameter and albedo

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According to the surveys carried out by the Japanese Akari satellite, the Spitzer Space Telescope and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), 1992 AX measures between 2.78 and 4.18 kilometers in diameter and its surface has an albedo between 0.199 and 0.40.[6][8][9]

In 2017, a study by WISE dedicated to Mars-crossing asteroids determined a diameter of 3.60 kilometers with a high albedo of 0.376.[7] The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.20 and derives a diameter of 3.79 kilometers based on an absolute magnitude of 14.47.[4] The Johnston's archive gives an effective (combined) diameter of 3.98 kilometers with 3.9 and 0.78 kilometers for is primary and secondary body, respectively.[3][5]

References

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  1. ^ a b c d e f g h "5407 (1992 AX)". Minor Planet Center. Retrieved 19 November 2018.
  2. ^ a b c d e f g "JPL Small-Body Database Browser: 5407 (1992 AX)" (2018-10-21 last obs.). Jet Propulsion Laboratory. Retrieved 19 November 2018.
  3. ^ a b c "Asteroid (5407) 1992 AX". Small Bodies Data Ferret. Retrieved 19 November 2018.
  4. ^ a b c d e f g "LCDB Data for (5407)". Asteroid Lightcurve Database (LCDB). Retrieved 19 November 2018.
  5. ^ a b c d e Johnston, Wm. Robert (18 February 2017). "Asteroids with Satellites Database – (450894) 2008 BT18". Johnston's Archive. Retrieved 19 November 2018.
  6. ^ 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. S2CID 119289027.
  7. ^ a b c d Alí-Lagoa, V.; Delbo', M. (July 2017). "Sizes and albedos of Mars-crossing asteroids from WISE/NEOWISE data". Astronomy and Astrophysics. 603: 8. arXiv:1705.10263. Bibcode:2017A&A...603A..55A. doi:10.1051/0004-6361/201629917. S2CID 119224590.
  8. ^ a b c d Marchis, F.; Enriquez, J. E.; Emery, J. P.; Mueller, M.; Baek, M.; Pollock, J.; et al. (November 2012). "Multiple asteroid systems: Dimensions and thermal properties from Spitzer Space Telescope and ground-based observations". Icarus. 221 (2): 1130–1161. arXiv:1604.05384. Bibcode:2012Icar..221.1130M. doi:10.1016/j.icarus.2012.09.013. S2CID 161887.
  9. ^ 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)
  10. ^ a b c d e f g h Pravec, Petr; Sarounová, Lenka; Rabinowitz, David L.; Hicks, Michael D.; Wolf, Marek; Krugly, Yurij N.; et al. (July 2000). "Two-Period Lightcurves of 1996 FG 3, 1998 PG, and (5407) 1992 AX: One Probable and Two Possible Binary Asteroids". Icarus. 146 (1): 190–203. Bibcode:2000Icar..146..190P. doi:10.1006/icar.2000.6375.
  11. ^ a b Pravec, P.; Scheirich, P.; Kusnirák, P.; Sarounová, L.; Mottola, S.; Hahn, G.; et al. (March 2006). "Photometric survey of binary near-Earth asteroids". Icarus. 181 (1): 63–93. Bibcode:2006Icar..181...63P. doi:10.1016/j.icarus.2005.10.014.
  12. ^ a b Sanchez, Juan A.; Michelsen, René; Reddy, Vishnu; Nathues, Andreas (July 2013). "Surface composition and taxonomic classification of a group of near-Earth and Mars-crossing asteroids". Icarus. 225 (1): 131–140. arXiv:1302.4449. Bibcode:2013Icar..225..131S. doi:10.1016/j.icarus.2013.02.036. S2CID 119207812.
  13. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 19 November 2018.
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