| 词条 | 2594 Acamas |
| 释义 |
| minorplanet = yes | name = 2594 Acamas | background = #C2FFFF | image = | image_size = | caption = | discovery_ref = [1] | discoverer = C. Kowal | discovery_site = Palomar Obs. | discovered = 4 October 1978 | mpc_name = (2594) Acamas | alt_names = 1978 TB{{·}}1977 RR | pronounced = {{IPAc-en|ˈ|æ|k|ə|m|ə|s}}{{·}}{{Respell|AK|ə|məs}} | named_after = {{nowrap|Acamas {{small|(Greek mythology)}}[1]}} | mp_category = Jupiter trojan [1] Trojan [5]{{·}}background [6] | orbit_ref = | epoch = 23 March 2018 (JD 2458200.5) | uncertainty = 0 | observation_arc = 64.44 yr (23,537 d) | aphelion = 5.4911 AU | perihelion = 4.6313 AU | semimajor = 5.0612 AU | eccentricity = 0.0849 | period = 11.39 yr (4,159 d) | mean_anomaly = 242.01° | mean_motion = {{Deg2DMS|0.0866|sup=ms}} / day | inclination = 5.5341° | asc_node = 356.69° | arg_peri = 279.28° | jupiter_moid = 0.082 AU | tisserand = 2.9840 | mean_diameter = {{val|25.87|0.59|ul=km}}[8] | rotation = {{val|25.954|0.0468|ul=h}} {{small|(R)}}[9][10] | albedo = {{val|0.060|0.006}}[8] | spectral_type = C {{small|(assumed)}}[9] | abs_magnitude = 11.6[8] 11.8[1] 12.31[9] }}2594 Acamas ({{IPAc-en|ˈ|æ|k|ə|m|ə|s}} {{Respell|AK|ə|məs}}), provisional designation {{mp|1978 TB}}, is a mid-sized Jupiter trojan from the Trojan camp, approximately {{convert|25|km|mi|abbr=off|sigfig=2|sp=us}} in diameter. It was discovered on 4 October 1978, by American astronomer Charles Kowal at the Palomar Observatory in California.[1] The dark Jovian asteroid has a longer-than average rotation period of 26 hours and possibly an elongated shape.[9] It was named after the Thracian leader Acamas from Greek mythology.[1] Orbit and classificationAcamas is a dark Jovian asteroid in a 1:1 orbital resonance with Jupiter. It is located in the trailering Trojan camp at the Gas Giant's {{L5}} Lagrangian point, 60° behind on its orbit {{cross reference|(see Trojans in astronomy)}}. It is also a non-family asteroid of the Jovian background population.[6]It orbits the Sun at a distance of 4.6–5.5 AU once every 11 years and 5 months (4,159 days; semi-major axis of 5.06 AU). Its orbit has an eccentricity of 0.08 and an inclination of 6° with respect to the ecliptic. The body's observation arc begins with a precovery taken at Palomar in September 1953, or 25 years prior to its official discovery observation.[1] Physical characteristicsAcamas is an assumed, carbonaceous C-type asteroid, while most larger Jupiter trojans are D-type asteroids.[9]Rotation periodIn September 2013, a rotational lightcurve of Acamas was obtained from photometric observations in the R-band by astronomers at the Palomar Transient Factory in California. Lightcurve analysis gave a rotation period of {{val|25.954|0.0468}} hours with a brightness amplitude of 0.50 magnitude ({{small|U=2}}).[9][10] A high brightness variation typically indicates that the body has an elongated rather than spherical shape. Diameter and albedoAccording to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Acamas measures 25.87 kilometers in diameter and its surface has an albedo 0.06,[8] while the Collaborative Asteroid Lightcurve Link assumes a standard albedo for a carbonaceous asteroid of 0.057 and calculates a diameter of 19.21 kilometers based on an absolute magnitude of 12.31.[9] NamingThis minor planet was named by IAU's Minor Planet Names Committee from Greek mythology after the warrior Acamas (son of Eussorus), ally of Troy and leader of the Thracian contingent during the Trojan War. He was killed by Ajax.[1] The name was suggested by Frederick Pilcher and published by the Minor Planet Center on 6 February 1993 ({{small|M.P.C. 21606}}).[1][30] References1. ^1 2 3 4 5 6 7 8 9 {{cite web |title = 2594 Acamas (1978 TB) |work = Minor Planet Center |url = https://www.minorplanetcenter.net/db_search/show_object?object_id=2594 |accessdate = 21 June 2018}} [1][2][3][4][5][6][7]2. ^1 {{cite web |title = List of Jupiter Trojans |work = Minor Planet Center |first3 = V. |last3 = Carruba |date = 1 June 2018 |url = https://www.minorplanetcenter.net/iau/lists/JupiterTrojans.html |accessdate = 21 June 2018}} 3. ^1 {{cite web |title = MPC/MPO/MPS Archive |work = Minor Planet Center |url = https://www.minorplanetcenter.net/iau/ECS/MPCArchive/MPCArchive_TBL.html |accessdate = 21 June 2018}} 4. ^1 2 3 4 {{cite journal |first1 = T. |last1 = Grav |first2 = A. K. |last2 = Mainzer |first3 = J. M. |last3 = Bauer |first4 = J. R. |last4 = Masiero |first5 = C. R. |last5 = Nugent |date = November 2012 |title = WISE/NEOWISE Observations of the Jovian Trojan Population: Taxonomy |url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2012ApJ...759...49G |journal = The Astrophysical Journal |volume = 759 |issue = 1 |page = 10 |bibcode = 2012ApJ...759...49G |doi = 10.1088/0004-637X/759/1/49 |arxiv = 1209.1549 |access-date= 21 June 2018}} (online catalog) 5. ^1 2 {{cite web |title = Asteroid (2594) Acamas – Proper Elements |publisher = AstDyS-2, Asteroids – Dynamic Site |url = http://hamilton.dm.unipi.it/astdys/index.php?n=2594&pc=1.1.6 |access-date= 21 June 2018}} 6. ^1 2 3 4 5 6 7 {{cite web |title = LCDB Data for (2594) Acamas |publisher = Asteroid Lightcurve Database (LCDB) |url = http://www.minorplanet.info/PHP/GenerateALCDEFPage_Local.php?AstInfo=2594%7CAcamas |accessdate = 21 June 2018}} 7. ^1 2 {{cite journal |display-authors = 6 |first1 = Adam |last1 = Waszczak |first2 = Chan-Kao |last2 = Chang |first3 = Eran O. |last3 = Ofek |first4 = Russ |last4 = Laher |first5 = Frank |last5 = Masci |first6 = David |last6 = Levitan |first7 = Jason |last7 = Surace |first8 = Yu-Chi |last8 = Cheng |first9 = Wing-Huen |last9 = Ip |first10 = Daisuke |last10 = Kinoshita |first11 = George |last11 = Helou |first12 = Thomas A. |last12 = Prince |first13 = Shrinivas |last13 = Kulkarni |date = September 2015 |title = Asteroid Light Curves from the Palomar Transient Factory Survey: Rotation Periods and Phase Functions from Sparse Photometry |url = https://arxiv.org/pdf/1504.04041.pdf |journal = The Astronomical Journal |volume = 150 |issue = 3 |page = 35 |bibcode = 2015AJ....150...75W |doi = 10.1088/0004-6256/150/3/75 |arxiv = 1504.04041 |access-date= 21 June 2018}} }} External links
5 : Jupiter trojans (Trojan camp)|Discoveries by Charles T. Kowal|Minor planets named from Greek mythology|Named minor planets|Astronomical objects discovered in 1978 |
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