148780 Altjira

(148780) Altjira
Discovery
Discovery site	Deep Ecliptic Survey at Kitt Peak
Discovery date	October 20, 2001 and; March, 2007 (secondary)
Designations
Designation	(148780) Altjira
Alternative names	2001 UQ18
Minor planet category	Cubewano (DES)
Orbital characteristics
	Epoch August 27, 2011 (JD 2455800.5)
Aphelion	47.166 AU
Perihelion	41.78 AU
Semi-major axis	44.474 AU
Eccentricity	0.0605
Orbital period (sidereal)	296.59 a (108,331 d)
Mean anomaly	112.0°
Inclination	5.1951°
Longitude of ascending node	1.769°
Argument of perihelion	304.4°
Known satellites	1
Physical characteristics
Dimensions	≈128–200 (primary) and 100–180 km (secondary)
Mass	3.952×1018 kg
Mean density	0.5–2.0 g/cm3
Albedo	0.06–0.14
Absolute magnitude (H)	5.76, 5.6, 5.4, or 5.1 (primary); secondary's magnitude difference with primary's: 0.7 ± 0.2

148780 Altjira /ælˈtʃ[invalid input: 'irr']ə/ is a binary classical Kuiper belt object (cubewano).^[2] The secondary, S/2007 (148780) 1, is large compared to the primary, 140 kilometres (87 mi) vs. 160 kilometres (99 mi).^[4] The Altjiran lightcurve is quite flat (Δmag<0.10), which is indicative of a "quasi-spherical body with a homogeneous surface".^[5]

The satellite's orbit has the following parameters: semi-major-axis, 9904 ± 56 km; period, 139.561 ± 0.047 days; eccentricity, 0.3445 ± 0.0045; and inclination, 35.19 ± 0.19°(retrograde). The total system mass is about 4 × 10¹⁸ kg.^[4]

It was named after the Arrernte creation deity, Altjira, who created the Earth during the Dreamtime and then retired to the sky.

References

^ ^a ^b ^c "JPL Small-Body Database Browser: 148780 Altjira (2001 UQ18)" (2008-10-02 last obs). Retrieved 2011-11-29.
^ ^a ^b ^c ^d ^e Johnston's Archive on (148780) Altjira Retrieved 2011-11-29
^ Marc W. Buie. "Orbit Fit and Astrometric record for 148780". SwRI (Space Science Department). Retrieved 2011-11-29.
^ ^a ^b ^c ^d ^e ^f Grundy, W. M.; Noll, K. S.; Nimmo, F.; Roe, H. G.; Buie, M. W.; Porter, S. B.; Benecchi, S. D.; Stephens, D. C.; Levison, H. F.; Stansberry, J. A. (2011). "Five new and three improved mutual orbits of transneptunian binaries" (pdf). Icarus. 213 (2): 678. arXiv:1103.2751. Bibcode:2011Icar..213..678G. doi:10.1016/j.icarus.2011.03.012.
^ ^a ^b Transneptunian objects and Centaurs from light curves

External links

148780 Altjira at the JPL Small-Body Database
- Close approach · Discovery · Ephemeris · Orbit viewer · Orbit parameters · Physical parameters

[jpldata-1] "JPL Small-Body Database Browser: 148780 Altjira (2001 UQ18)" (2008-10-02 last obs). Retrieved 2011-11-29.

[Johnston-2] Johnston's Archive on (148780) Altjira Retrieved 2011-11-29

[Buie-3] Marc W. Buie. "Orbit Fit and Astrometric record for 148780". SwRI (Space Science Department). Retrieved 2011-11-29.

[Grundy2011-4] ^ ^a ^b ^c ^d ^e ^f Grundy, W. M.; Noll, K. S.; Nimmo, F.; Roe, H. G.; Buie, M. W.; Porter, S. B.; Benecchi, S. D.; Stephens, D. C.; Levison, H. F.; Stansberry, J. A. (2011). "Five new and three improved mutual orbits of transneptunian binaries" (pdf). Icarus. 213 (2): 678. arXiv:1103.2751. Bibcode:2011Icar..213..678G. doi:10.1016/j.icarus.2011.03.012.

[lightcurves-5] Transneptunian objects and Centaurs from light curves

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