| 词条 | 2014 JO25 |
| 释义 |
| minorplanet = yes | name = {{mp|2014 JO|25}} | background = #FFC2E0 | image = PIA21597 fig1.gif | image_size = 260 | caption = Radar image of 2014 JO25 taken at Goldstone on 19 Apr 2017 | discovery_ref = | discoverer = Mount Lemmon Srvy. | discovery_site = Mount Lemmon Obs. {{small|(first observation only)}} | discovered = 5 May 2014 | mpc_name = {{mp|2014 JO|25}} | alt_names = | pronounced = | named_after = | mp_category = {{nowrap|NEO{{·}}Apollo{{·}}PHA [3]}} | orbit_ref = | epoch = 23 March 2018 (JD 2458200.5) | uncertainty = 0 | observation_arc = 6.02 yr (2,200 days) | aphelion = 3.8996 AU | perihelion = 0.2364 AU | semimajor = 2.0680 AU | eccentricity = 0.8857 | period = 2.97 yr (1,086 days) | mean_anomaly = 125.06° | mean_motion = {{Deg2DMS|0.3314|sup=ms}} / day | inclination = 25.261° | asc_node = 30.637° | arg_peri = 49.571° | moid = 0.0110 AU (4.3 LD) | mercury_moid = 0.0210 AU[3] | venus_moid = 0.0412 AU[3] | mean_diameter = 0.72 km {{small|(est. at 0.20)}}[7] 0.818 km {{small|(calculated)}}[8] | rotation = {{val|4.531}} h[8] | albedo = 0.20 {{small|(assumed)}}[8] | spectral_type = S {{small|(assumed)}}[8] | abs_magnitude = 17.8[8]{{·}}18.1 }} {{mp|2014 JO|25}} is an asteroid. It was discovered in May 2014 by astronomers at the Catalina Sky Srvey near Tucson, Arizona - a project of NASA's NEO (Near Earth Object) Observations Program in collaboration with the University of Arizona. Orbit and classification{{mp|2014 JO|25}} belongs to the Apollo asteroids, which cross the orbit of Earth. Apollos are the largest group of near-Earth objects with nearly 10 thousand known members. It is also a potentially hazardous asteroid due to its sufficiently large size (an absolute magnitude brighter than 22), and its Earth-MOID (see below) of less than 0.05 AU.It orbits the Sun at a distance of 0.25–3.90 AU once every 3 years (1,086 days; semi-major axis of 2.07 AU). Its orbit has an eccentricity of 0.89 and an inclination of 25° with respect to the ecliptic. This makes it also a Venus- and Mercury-crossing asteroid. The body's observation arc begins with a precovery taken by Pan-STARRS in May 2011, or 3 years prior to its official first observation at Mount Lemmon.[3] Close approachesThis asteroid has a minimum orbital intersection distance (MOID) with Earth of {{convert |0.0110 |AU |km mi |abbr=on |lk=off |sigfig=3 |order=flip}}, which translates into 4.3 lunar distances. 2017 Earth flyby{{mp|2014 JO|25}} made a close flyby of Earth on 19 April 2017, and at its closest approach on that date came within 1.8 million kilometers (1.1 million miles) of the planet. It reached an apparent magnitude of 10.76.The 2017-flyby within a distance of 1.8 million kilometers was the closest approach to Earth by {{mp|2014 JO|25}} for at least the next 400 years.[1] {{Large near earth asteroid flybys 5LD}}Physical characteristics{{mp|2014 JO|25}} is a peanut-shaped contact binary. It is an assumed stony S-type asteroid.[8]Diameter and albedoEarly estimation based on observed absolute magnitude and estimated albedo indicates object 600–1400 meters (m) in diameter. In 2014, further research based on NEOWISE data indicated an object of 650 m in diameter and albedo 0.25.[2] Based on a generic magnitude-to-mean-diameter conversion, {{mp|2014 JO|25}} measures approximately 720 m in diameter, using an absolute magnitude of 18.1 and assuming an albedo of 0.20, which is typical for stony asteroids.[7] The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.20 and calculates a diameter of 818 meters based on an absolute magnitude of 17.8.[8] Observation of the asteroid with the Goldstone Solar System Radar were performed between April 15 and 21, 2017 by Arecibo Observatory and Goldstone Solar System Radar. Results show that the largest dimension of this contact binary is at least 870 meters.[8][23] Rotation periodThe 2017 radiometric observations at Arecibo and Goldstone also gave a rotation period of approximately 4.5 hours.[23] Also in April 2017, a rotational lightcurve of this asteroid was obtained from photometric observations by Brian Warner at the Palmer Divide Station ({{small|U82}}) in California. Lightcurve analysis gave a refined period of 4.531 hours with a brightness amplitude between 0.14 and 0.64 magnitude ({{small|U=n.a.}}).[25] Numbering and namingAs of 2018, this minor planet has not been numbered or named.[3] GalleryRadar images of the asteroid were taken on 18 April 2017 by the Goldstone Solar System Radar: In Context2014 JO25 on a graph plotting the closest flyby distance to Earth and size of NEOs in 2017. {{Clear}}References1. ^http://earthsky.org/astronomy-essentials/large-asteroid-2014-jo25-close-april-19-2017-how-to-see [3][4][5][6][7]2. ^https://echo.jpl.nasa.gov/asteroids/2014JO25/2014JO25_planning.html 3. ^1 2 3 4 5 {{cite web |title = 2014 JO25 |work = Minor Planet Center |url = https://www.minorplanetcenter.net/db_search/show_object?object_id=2014+JO25 |accessdate = 21 February 2018}} 4. ^1 {{Cite journal |last = Warner |first= Brian D. |date = October 2017 |title = Lightcurve Analysis of Two Near-Earth Asteroids: 2010 VB1 and 2014 JO25 |url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2017MPBu...44..327W |journal = The Minor Planet Bulletin |volume = 44 |issue = 4 |pages = 327–330 |issn = 1052-8091 |bibcode = 2017MPBu...44..327W |access-date= 21 February 2018}} 5. ^1 2 3 4 5 6 7 8 {{cite web |title = LCDB Data for 2014 JO25 |publisher = Asteroid Lightcurve Database (LCDB) |url = http://www.minorplanet.info/PHP/GenerateALCDEFPage_Local.php?AstInfo=0%7C2014+JO25 |accessdate = 21 February 2018}} 6. ^1 2 {{cite web |title = Asteroid Size Estimator |publisher = CNEOS NASA/JPL |url = https://cneos.jpl.nasa.gov/tools/ast_size_est.html |accessdate = 21 February 2018}} 7. ^1 2 {{Cite web |title = Planetary Radar Science Group |publisher = National Astronomy and Ionosphere Center (NAIC) |url = http://www.naic.edu/~pradar/press/2014JO25.php |accessdate = 21 February 2018}} }} External links{{Commons category|2014 JO25}}
6 : Apollo asteroids|Minor planet object articles (unnumbered)|Contact binary (asteroid)|Potentially hazardous asteroids|Near-Earth objects in 2017|Astronomical objects discovered in 2014 |
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