| 词条 | (386454) 2008 XM |
| 释义 |
| minorplanet = yes | name = (386454) 2008 XM | background = #FFC2E0 | image = | image_size = | caption = | discovery_ref = | discovered = 2 December 2008 | discoverer = LINEAR | discovery_site = Lincoln Lab's ETS | mpc_name = (386454) 2008 XM | alt_names = 2008 XM | pronounced = | named_after = | mp_category = {{nowrap|Apollo{{·}}NEO{{·}}PHA [3]}} | orbit_ref = | epoch = 4 September 2017 (JD 2458000.5) | uncertainty = 0 | observation_arc = 5.16 yr (1,884 days) | aphelion = 2.3334 AU | perihelion = 0.1111 AU | semimajor = 1.2222 AU | eccentricity = 0.9091 | period = 1.35 yr (494 days) | mean_anomaly = 204.67° | mean_motion = {{Deg2DMS|0.7294|sup=ms}} / day | inclination = 5.4478° | asc_node = 240.63° | arg_peri = 27.357° | moid = 0.0048 AU{{·}}1.9 LD | dimensions = {{val|0.367|0.009}} km[5] | rotation = | albedo = {{val|0.128|0.032}}[5] | spectral_type = | abs_magnitude = 20.0 }}(386454) 2008 XM is an outstandingly eccentric, sub-kilometer-sized asteroid, with one of the smallest known perihelions among all minor planets. It is classified as near-Earth object of the Apollo group and was discovered on 2 December 2008, by the LINEAR program at Lincoln Laboratory's Experimental Test Site in Socorro, New Mexico, United States.[3] Orbit and classificationThe asteroid orbits the Sun at a distance of 0.1–2.3 AU once every 16 months (494 days). Its orbit has an eccentricity of 0.91 and an inclination of 5° with respect to the ecliptic. Due to its outstanding eccentricity, it is also a Mercury-crosser, Venus-crosser and Mars-crosser. It has the third-smallest perihelion of any numbered asteroid behind {{mpl|(137924) 2000 BD|19}} and {{mpl|(374158) 2004 UL}}.{{citation needed|date=October 2016}} Its Earth minimum orbital intersection distance of {{convert|0.0047|AU|km|abbr=on|lk=off|sigfig=2}} corresponds to only 1.9 lunar distances. Physical characteristicsAccording to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, the asteroid measures {{val|367|9}} meters in diameter and its surface has an albedo of 0.128.[5] As of 2016, the body's composition and spectral type, as well as its rotation period and shape remains unknown. NamingAs of 2017, this minor planet remains unnamed.[3] References1. ^1 2 3 {{cite web |title = 386454 (2008 XM) |work = Minor Planet Center |url = http://www.minorplanetcenter.net/db_search/show_object?object_id=386454 |accessdate = 26 October 2016}} [1][2]2. ^1 2 3 {{Cite journal |display-authors = 6 |first1 = A. |last1 = Mainzer |first2 = J. |last2 = Bauer |first3 = T. |last3 = Grav |first4 = J. |last4 = Masiero |first5 = R. M. |last5 = Cutri |first6 = E. |last6 = Wright |first7 = C. R. |last7 = Nugent |first8 = R. |last8 = Stevenson |first9 = E. |last9 = Clyne |first10 = G. |last10 = Cukrov |first11 = F. |last11 = Masci |date = April 2014 |title = The Population of Tiny Near-Earth Objects Observed by NEOWISE |url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2014ApJ...784..110M |journal = The Astrophysical Journal |volume = 784 |issue = 2 |page = 7 |bibcode = 2014ApJ...784..110M |doi = 10.1088/0004-637X/784/2/110 |arxiv = 1310.2980 |access-date= 26 October 2016}} }} External links
6 : Apollo asteroids|Discoveries by LINEAR|Potentially hazardous asteroids|Mercury-crossing asteroids|Venus-crosser asteroids|Astronomical objects discovered in 2008 |
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