Astronomy:148780 Altjira
From HandWiki
 Altjira and its companion imaged by the Hubble Space Telescope in 2006 | |
| Discovery | |
|---|---|
| Discovery site | Deep Ecliptic Survey at Kitt Peak[1] |
| Discovery date | 20 October 2001 August 2006 (secondary)[2] |
| Designations | |
| (148780) Altjira | |
| Pronunciation | /ælˈtʃɪrə/ |
| 2001 UQ18 | |
| Minor planet category | Cubewano (DES)[3] |
| Adjectives | Altjirian |
| Orbital characteristics[1] | |
| Epoch 13 January 2016 (JD 2457400.5) | |
| Uncertainty parameter 3 | |
| Observation arc | 2539 days (6.95 yr) |
| |{{{apsis}}}|helion}} | 46.877 astronomical unit|AU (7.0127 Tm) |
| |{{{apsis}}}|helion}} | 41.572 AU (6.2191 Tm) |
| 44.224 AU (6.6158 Tm) | |
| Eccentricity | 0.059979 |
| Orbital period | 294.10 yr (107421 d) |
| Mean anomaly | 124.29° |
| Mean motion | 0.0033513°/day |
| Inclination | 5.2056° |
| Longitude of ascending node | 2.0132° |
| 297.71° | |
| Known satellites | 1 |
| Physical characteristics | |
| Dimensions | ≈128–200 (primary)[4] and 100–180 km (secondary) |
| Mass | 3.952×1018 kg[4] |
| Mean density | 0.5–2.0 g/cm3[4] |
| Geometric albedo | 0.06–0.14[4] |
| Absolute magnitude (H) | 5.7[1] 5.6,[5] 5.4,[2] or 5.1[2] (primary) secondary's magnitude difference with primary's: 0.7 ± 0.2[2] |
148780 Altjira /ælˈtʃɪrə/ 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.[1]
References
- ↑ 1.0 1.1 1.2 1.3 "JPL Small-Body Database Browser: 148780 Altjira (2001 UQ18)". https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=148780. Retrieved 26 March 2016.
- ↑ 2.0 2.1 2.2 2.3 2.4 Johnston's Archive on (148780) Altjira Retrieved 2011-11-29
- ↑ Marc W. Buie. "Orbit Fit and Astrometric record for 148780". SwRI (Space Science Department). http://www.boulder.swri.edu/~buie/kbo/astrom/148780.html. Retrieved 2011-11-29.
- ↑ 4.0 4.1 4.2 4.3 4.4 4.5 Grundy, W. M.; Noll, K. S.; Nimmo, F.; Roe, H. G.; Buie, M. W.; Porter, S. B.; Benecchi, S. D.; Stephens, D. C. et al. (2011). "Five new and three improved mutual orbits of transneptunian binaries". Icarus 213 (2): 678. doi:10.1016/j.icarus.2011.03.012. Bibcode: 2011Icar..213..678G. http://es.ucsc.edu/~fnimmo/website/Grundy_KBO.pdf.
- ↑ 5.0 5.1 Transneptunian objects and Centaurs from light curves
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