7088 Ishtar

7088 Ishtar, provisional designation 1992 AA, is a synchronous binary asteroid and near-Earth object from the Amor group, approximately 1.3 kilometers (0.81 miles) in diameter. It was discovered on 1 January 1992, by American astronomer Carolyn Shoemaker at the Palomar Observatory in California.[1] The relatively bright asteroid with an unknown spectral type has a rotation period of 2.7 hours.[10][11] In December 2005, a 330-meter sized satellite was discovered, orbiting its primary every 20.65 hours.[6]

7088 Ishtar
Discovery [1]
Discovered byC. Shoemaker
Discovery sitePalomar Obs.
Discovery date1 January 1992
Designations
(7088) Ishtar
Pronunciation/ˈɪʃtɑːr/[2]
Named after
Ishtar [1]
(Mesopotamian goddess)
1992 AA
NEO · Amor [1][3]
Binary [4][5]
Orbital characteristics [3]
Epoch 27 April 2019 (JD 2458600.5)
Uncertainty parameter 0
Observation arc38.52 yr (14,071 d)
Aphelion2.7551 AU
Perihelion1.2057 AU
1.9804 AU
Eccentricity0.3912
2.79 yr (1,018 d)
284.83°
0° 21m 12.96s / day
Inclination8.3045°
102.65°
354.73°
Known satellites1[4][5]
(P:20.65 h; D: 330 m)[4][6][7]
Earth MOID0.2230 AU (86.9 LD)
Physical characteristics
Mean diameter
1.298±0.261 km (primary)[8]
1.51 km (effective)[9]
2.6790±0.0002 h[6][7]
0.260±0.122[8]
U [10]
16.7[1]
16.80[3][8]

    Orbit and classification

    Ishtar orbits the Sun at a distance of 1.2–2.8 AU once every 2 years and 9 months (1,018 days; semi-major axis of 1.98 AU). Its orbit has an eccentricity of 0.39 and an inclination of 8° with respect to the ecliptic.[3] The body's observation arc begins with its first observation at the Siding Spring Observatory in March 1981, almost 11 years prior to its official discovery observation at Palomar.[1]

    Naming

    This minor planet was named after the ancient Mesopotamian goddess Ishtar (Inanna). She is the principal goddess of the Assyrians and Babylonians associated with love, fertility, sex and war. The official naming citation was published by the Minor Planet Center on 22 April 1997 (M.P.C. 29671).[12]

    Physical characteristics

    Ishtar has an unknown spectral type (U).[10] The Collaborative Asteroid Lightcurve Link (CALL) assumes standard S-type asteroid due to its relatively high albedo (see below).[11]

    Rotation period

    In December 2005, a rotational lightcurve of Ishtar was obtained from photometric observations by Vishnu Reddy and collaborators. Lightcurve analysis gave a rotation period of 2.6790±0.0002 h hours with a brightness amplitude of 0.11 magnitude (U=3).[6][7][13]

    Diameter and albedo

    According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Ishtar measures 1.298 kilometers in diameter and its surface has an albedo of 0.26.[8][7] The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.20 and derives a diameter of 1.16 kilometers based on an absolute magnitude of 17.08.[11]

    References
    1. "7088 Ishtar (1992 AA)". Minor Planet Center. Retrieved 5 October 2019.
    2. "Ishtar". Lexico UK Dictionary. Oxford University Press.
    3. "JPL Small-Body Database Browser: 7088 Ishtar (1992 AA)" (2019-09-11 last obs.). Jet Propulsion Laboratory. Retrieved 5 October 2019.
    4. Johnston, Wm. Robert (29 May 2019). "Asteroids with Satellites Database – 7088 Ishtar (1992 AA)". Johnston's Archive. Retrieved 5 October 2019.
    5. Dr. Lance A. M. Benner (18 November 2013). "Binary and Ternary near-Earth Asteroids detected by radar". NASA/JPL Asteroid Radar Research. Retrieved 1 March 2014.
    6. Reddy, V.; Dyvig, R.; Pravec, P.; Kusnirak, P. (February 2005). "2005 AB". IAU Circ. 8483 (8483): 3. Bibcode:2005IAUC.8483....3R. ((7088) Ishtar, CBET 384)
    7. Pravec, P.; Scheirich, P.; Kusnirák, P.; Hornoch, K.; Galád, A.; Naidu, S. P.; et al. (March 2016). "Binary asteroid population. 3. Secondary rotations and elongations". Icarus. 267: 267–295. Bibcode:2016Icar..267..267P. doi:10.1016/j.icarus.2015.12.019.
    8. Masiero, Joseph R.; Nugent, C.; Mainzer, A. K.; Wright, E. L.; Bauer, J. M.; Cutri, R. M.; et al. (October 2017). "NEOWISE Reactivation Mission Year Three: Asteroid Diameters and Albedos". The Astronomical Journal. 154 (4): 10. arXiv:1708.09504. Bibcode:2017AJ....154..168M. doi:10.3847/1538-3881/aa89ec.
    9. "Asteroid 7088 Ishtar". Small Bodies Data Ferret. Retrieved 5 October 2019.
    10. Carry, B.; Solano, E.; Eggl, S.; DeMeo, F. E. (April 2016). "Spectral properties of near-Earth and Mars-crossing asteroids using Sloan photometry". Icarus. 268: 340–354. arXiv:1601.02087. Bibcode:2016Icar..268..340C. doi:10.1016/j.icarus.2015.12.047.
    11. "LCDB Data for (7088) Ishtar". Asteroid Lightcurve Database (LCDB). Retrieved 5 October 2019.
    12. "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 5 October 2019.
    13. Reddy, V.; Dyvig, R. R.; Pravec, P.; Kusnirák, P.; Gajdos, S.; Galád, A.; et al. (March 2007). "Photometric Observations of Binary Near-Earth Asteroid (7088) Ishtar and (11405) 1999 CV3" (PDF). 38th Lunar and Planetary Science Conference (PDF) (1338): 1239. Bibcode:2007LPI....38.1239R. Retrieved 5 October 2019.
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