Caliban (moon)
Discovery[1] | |
---|---|
Discovered by |
|
Synodic rotation period | 9.948±0.019 hr (double-peaked)[7] 2.66±0.04 hr (single-peaked)[9] |
Albedo | 0.22+0.20 −0.12[7] |
Temperature | ~65 K (mean estimate) |
22.0 (V)[7] | |
9.160±0.016[7] 9.0[5] | |
Caliban
Designated Uranus XVI, it was named after the monster
Orbit
Caliban follows a distant orbit, more than 10 times further from Uranus than the furthest regular moon
The diagram illustrates the orbital parameters of the retrograde
Physical characteristics
Caliban's diameter is estimated to be around 42 km, based on thermal measurements by the Herschel Space Observatory.[7] Its albedo is estimated at around 0.22, which is unusually high compared to those of other Uranian irregular satellites. Neptune's largest irregular satellite, Nereid, has a similarly high albedo as Caliban.[7]
Somewhat inconsistent reports put Caliban in light-red category (B–V = 0.83 V–R = 0.52,[12] B–V = 0.84 ± 0.03 V–R = 0.57 ± 0.03[11]), redder than Himalia but still less red than most Kuiper belt objects. Caliban may be slightly redder than Sycorax.[9] It also absorbs light at 0.7 μm, and one group of astronomers think this may be a result of liquid water that modified the surface.[13]
Measurements of Caliban's light curve by the Kepler space telescope indicate that its rotation period is about 9.9 hours.[7]
Origin
Caliban is hypothesized to be a captured object: it did not form in the accretionary disk that existed around Uranus just after its formation. The exact capture mechanism is not known, but capturing a moon requires the dissipation of energy. The possible capture processes include: gas drag in the protoplanetary disk, many body interactions and the capture during the fast growth of the Uranus' mass (so-called "pull-down").[10][11]
See also
References
- ^ a b c Gladman Nicholson et al. 1998.
- ^ "Caliban". Oxford English Dictionary (Online ed.). Oxford University Press. (Subscription or participating institution membership required.)
- ^ Benjamin Smith (1903) The Century Dictionary and Cyclopedia
- ^ Apple, Au, & Gandin (2009) The Routledge international handbook of critical education
- ^ a b "M.P.C. 95215" (PDF). Minor Planet Circular. Minor Planet Center. 29 August 2015.
- ^ Brozovic, M.; Jacobson, R. A. (2009). "Planetary Satellite Mean Orbital Parameters". The Orbits of the Outer Uranian Satellites, Astronomical Journal, 137, 3834. JPL/NASA. Retrieved 2011-11-06.
- ^ S2CID 118869078. 119.
- ^ a b
"Planetary Satellite Physical Parameters". JPL(Solar System Dynamics). 20 December 2008. Retrieved 10 March 2009.
- ^ a b
Maris, Michele; Carraro, Giovanni; Cremonese, Gabrielle; Fulle, Marco (May 2001). "Multicolor Photometry of the Uranus Irregular Satellites Sycorax and Caliban". The Astronomical Journal. 121 (5): 2800–2803. S2CID 16273706.
- ^ a b Sheppard, Jewitt & Kleyna 2005.
- ^ a b c Grav, Holman & Fraser 2004.
- ^ Rettig, Walsh & Consolmagno 2001.
- ^
Schmude, Richard (2008). Uranus, Neptune, Pluto and How to Observe Them. Springer. ISBN 978-0-387-76601-0.
- S2CID 4315601.
- Grav, Tommy; S2CID 15706906.
- Rettig, T. W.; Walsh, K.; .
- Sheppard, S. S.; Jewitt, D.; Kleyna, J. (2005). "An Ultradeep Survey for Irregular Satellites of Uranus: Limits to Completeness". The Astronomical Journal. 129 (1): 518–525. S2CID 18688556.