| 词条 | Caliban (moon) |
| 释义 |
| name = Caliban | adjectives = Calibanian | image = Caliban_feat.png | caption = Discovery image of Caliban | discoverer =
| discovered = September 6, 1997 | discovery_ref = {{sfn|Gladman Nicholson et al.|1998|p=}} | mean_orbit_radius = 7,231,000 km{{sfn|Sheppard|Jewitt|Kleyna|2005|p=523|loc=Table 3}}[1] | eccentricity = 0.1812[1] | period = 579.73 d | avg_speed = 0.91 km/s{{efn|name=calculated|Calculated on the basis of other parameters.}} | inclination =
| satellite_of = Uranus | mean_radius = 36 km (estimate){{refn|name=Sheppard et al. 2005 radius/albedo}}[3] | surface_area = ~16,000 km² (estimate) | volume = ~200,000 km³ (estimate) | mass = ~2.5{{E|17}} kg (estimate) | surface_grav = ~0.02 m/s² (estimate) | escape_velocity = ~0.031 km/s (estimate) | density = ~1.3 g/cm³ (assumed) | rotation = 2.7h[4] | axial_tilt = ? | albedo = 0.04 (assumed){{refn|name=Sheppard et al. 2005 radius/albedo}} | single_temperature = ~65 K (estimate) }} Caliban ({{IPAc-en|ˈ|k|æ|l|ɪ|b|æ|n}} {{respell|KAL|i|ban}} or {{IPAc-en|ˈ|k|æ|l|ɪ|b|ən}} {{respell|KAL|i|bən}}) is the second-largest retrograde irregular satellite of Uranus.{{sfn|Sheppard|Jewitt|Kleyna|2005|p=}} It was discovered on 6 September 1997 by Brett J. Gladman, Philip D. Nicholson, Joseph A. Burns, and John J. Kavelaars using the 200-inch Hale telescope together with Sycorax and given the temporary designation S/1997 U 1.{{sfn|Gladman Nicholson et al.|1998|p=}} Designated Uranus XVI, it was named after the monster character in William Shakespeare's play The Tempest. OrbitCaliban follows a distant orbit, more than 10 times further from Uranus than the furthest regular moon Oberon.{{sfn|Gladman Nicholson et al.|1998|p=}} Its orbit is retrograde, moderately inclined and slightly eccentric. The orbital parameters suggest that it may belong to the same dynamic cluster as Stephano and Francisco, suggesting common origin.{{sfn|Grav|Holman|Fraser|2004|p=}} The diagram illustrates the orbital parameters of the retrograde irregular satellites of Uranus (in polar co-ordinates) with the eccentricity of the orbits represented by the segments extending from the pericentre to the apocentre. Physical characteristicsIts diameter is estimated at 72 km (assuming albedo of 0.04){{sfn|Sheppard|Jewitt|Kleyna|2005|p=}}[3] making it the second largest irregular satellite of Uranus, half the size of Sycorax, the biggest irregular satellite of Uranus. Somewhat inconsistent reports put Caliban in light-red category ({{nowrap|B–V {{=}} 0.83}} {{nowrap|V–R {{=}} 0.52}},{{sfn|Rettig|Walsh|Consolmagno|2001|p=}} {{nowrap|B–V {{=}} 0.84 ± 0.03}} {{nowrap|V–R {{=}} 0.57 ± 0.03}}{{sfn|Grav|Holman|Fraser|2004|p=}}), redder than Himalia but still less red than most Kuiper belt objects. Caliban may be slightly redder than Sycorax.[4] 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.[7] The light curve suggests the rotation period of Caliban is about 2.7h.[4] OriginCaliban 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").{{sfn|Sheppard|Jewitt|Kleyna|2005|p=}}{{sfn|Grav|Holman|Fraser|2004|p=}} See also
Footnotes1. ^1 2 {{cite web| last1 = Brozovic| first1 = M.| last2 = Jacobson| first2 = R. A.| year = 2009| title = Planetary Satellite Mean Orbital Parameters| publisher = JPL/NASA| work = The Orbits of the Outer Uranian Satellites, Astronomical Journal, 137, 3834| url = http://ssd.jpl.nasa.gov/?sat_elem#uranus| accessdate = 2011-11-06}} 2. ^{{harvnb|Sheppard|Jewitt|Kleyna|2005|p=523|loc=Table 3 ... ri (km) ... 36 ... i Radius of satellite assuming a geometric albedo of 0.04}}. 3. ^1 2 {{cite web| publisher = JPL (Solar System Dynamics)| title = Planetary Satellite Physical Parameters| date = 20 December 2008| url = http://ssd.jpl.nasa.gov/?sat_phys_par| accessdate = 10 March 2009}} 4. ^1 2 3 {{cite journal| doi = 10.1086/320378| last1 = Maris| first1 = Michele| last2 = Carraro| first2 = Giovanni| last3 = Cremonese| first3 = Gabrielle| last4 = Fulle| first4 = Marco|date=May 2001| title = Multicolor Photometry of the Uranus Irregular Satellites Sycorax and Caliban| journal = The Astronomical Journal| volume = 121| issue = 5| pages = 2800–2803| url = http://www.iop.org/EJ/article/1538-3881/121/5/2800/200443.html| accessdate = 14 September 2008| bibcode = 2001AJ....121.2800M| arxiv = astro-ph/0101493}} 5. ^1 {{cite book| first = Richard| last = Schmude| year = 2008| title = Uranus, Neptune, Pluto and How to Observe Them| publisher = Springer| isbn = 978-0-387-76601-0| url = https://books.google.com/books?id=kqNr7rjw028C&pg=PA58&lpg=PA58#v=onepage&q=}} References{{reflist| colwidth = 30em | refs =[1][2][3][4][5] }}
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External links
3 : Moons of Uranus|Irregular satellites|Astronomical objects discovered in 1997 |
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