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 | |
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) |
Aphelion | 46.877 AU (7.0127 Tm) |
Perihelion | 41.572 AU (6.2191 Tm) |
44.224 AU (6.6158 Tm) | |
Eccentricity | 0.059979 |
294.10 yr (107421 d) | |
124.29 ° | |
0.0033513°/day | |
Inclination | 5.2056° |
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] |
0.06–0.14 [4] | |
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]
Altjira may be an unresolved hierarchical triple system. [6]
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 | |
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) |
Aphelion | 46.877 AU (7.0127 Tm) |
Perihelion | 41.572 AU (6.2191 Tm) |
44.224 AU (6.6158 Tm) | |
Eccentricity | 0.059979 |
294.10 yr (107421 d) | |
124.29 ° | |
0.0033513°/day | |
Inclination | 5.2056° |
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] |
0.06–0.14 [4] | |
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]
Altjira may be an unresolved hierarchical triple system. [6]