| 词条 | Actaea (moon) |
| 释义 |
|name = Actaea |image = Salacia Actaea orbit simulation.png |caption = Simulation of Actaea's orbit relative to Salacia. |background = #a0ffa0 |discoverer = Keith S. Noll, Harold F. Levison, Denise C. Stephen, William M. Grundy |discovered = 21 Jul 2006 |alt_names = S/2006 (120347) 1, Salacia I |pronounced = |adjectives = Actaean |semimajor = 5619 ± 87 km |eccentricity = 0.0084 ± 0.0076 |period = 5.49380 ± 0.00016 days |inclination = |satellite_of = {{dp|Salacia}} |dimensions = 303 ± 35 km |mass = 1.86{{E-sp|19}} kg |density = 1.16 +0.59/-0.36 g/cm³ |escape_velocity = ≈ 0.05 km/s |surface_grav = |single_temperature = |rotation = |axial_tilt = |albedo = ≈ 0.035 +0.010/−0.007 |spectral_type = |magnitude = |abs_magnitude = 1.9 mag }} Actaea, officially (120347) Salacia I Actaea, is the single known natural satellite of the classical Kuiper belt object 120347 Salacia. Its diameter is estimated 300 km, which is ⅓ of the diameter of Salacia; thus, Salacia and Actaea are viewed by some to be a binary object. Given that the following size estimates are correct, Actaea is about the sixth-biggest known moon of a trans-Neptunian object, after Charon (1212 km), Dysnomia (685 km), Vanth (378 km), Ilmarë (361 km) and Hiʻiaka (320 km). Discovery and nameIt was discovered on 21 July 2006 by Keith S. Noll, Harold Levison, Denise Stephens and Will Grundy with the Hubble Space Telescope.[1] On 18 February 2011, it was officially named Actaea after the nereid Aktaia. OrbitActaea orbits its primary every {{val|5.493|u=d}} at a distance of {{val|5619|87|u=km}} and with an eccentricity of {{val|0.0084|0.0076}}.[2] The ratio of its semi-major axis to its primary's Hill radius is 0.0023, the tightest trans-Neptunian binary with a known orbit.[3] Physical characteristicsActaea is {{val|2.372|0.060}} magnitudes fainter than Salacia,[3] implying a diameter ratio of 2.98 for equal albedos.[4] Hence, assuming equal albedos, it has a diameter of {{val|303|35|u=km}}[3] Actaea has the same color as Salacia (V−I = {{val|0.89|0.02}} and {{val|0.87|0.01}}, respectively), supporting the assumption of equal albedos.[4] It has been calculated that the Salacia system should have undergone enough tidal evolution to circularize their orbits, which is consistent with the low measured eccentricity, but that the primary need not have been tidally locked.[4] The low density calculated for the system (1.16 g/cm3) implies that both Salacia and Actaea consist chiefly of water ice. Salacia and Actaea will next occult each other in 2067.[4] The mass of the system is 4.66 ± 0.22 {{E-sp|20}} kg, with about 4% of this being in Actaea.[4] References1. ^{{cite web |url=http://www.cbat.eps.harvard.edu/iauc/08700/08751.html |title=IAUC 8751: (120347) 2004 SB_60; 2006gi, 2006gj; V733 Cep |publisher=Cbat.eps.harvard.edu |accessdate=2014-06-14 |deadurl=yes |archiveurl=https://web.archive.org/web/20131203012326/http://www.cbat.eps.harvard.edu/iauc/08700/08751.html |archivedate=2013-12-03 |df= }} 2. ^Johnston Archive: (120347) Salacia and Actaea 3. ^1 {{cite journal |first=S. |last=Fornasier |first2=E.|last2=Lellouch |first3=T.|last3=Müller, P. |display-authors=etal |title=TNOs are Cool: A survey of the trans-Neptunian region. VIII. Combined Herschel PACS and SPIRE observations of 9 bright targets at 70–500 µm |journal=Astronomy & Astrophysics |volume=555 |pages=A92 |doi=10.1051/0004-6361/201321329 |date=2013 |arxiv=1305.0449|bibcode = 2013A&A...555A..15F }} 4. ^1 2 3 4 5 {{cite journal |title=Physical Properties of Trans-Neptunian Binaries (120347) Salacia–Actaea and (42355) Typhon–Echidna |journal=Icarus |volume=219 |pages=676–688 |first=J.A. |last=Stansberry |first2=W.M. |last2=Grundy |first3=M. |last3= Mueller |displayauthors=etal |date=2012 |citeseerx = 10.1.1.398.6675 |doi=10.1016/j.icarus.2012.03.029 |url=http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.398.6675&rep=rep1&type=pdf|bibcode = 2012Icar..219..676S }} 5 : Minor planet satellites|Kuiper belt objects|120347 Salacia|Astronomical objects discovered in 2006|Discoveries by Denise C. Stephens |
| 随便看 |
|
开放百科全书收录14589846条英语、德语、日语等多语种百科知识，基本涵盖了大多数领域的百科知识，是一部内容自由、开放的电子版国际百科全书。