- 2004 XR190
Infobox Planet
bgcolour=#FFFFC0
name=mp|2004 XR|190
discovery=yes
discoverer=Lynne Jones,Brett Gladman ,John J. Kavelaars ,Jean-Marc Petit , Joel Parker,Phil Nicholson
discovered=December 11 ,2004
mp_name=mp|2004 XR|190
alt_names="none"
mp_category=detached object
epoch=June 14 ,2006 (JD 2453900.5)
semimajor=8534.532 Gm (57.050 AU)
perihelion=7826.404 Gm (52.316 AU)
aphelion=9242.660 Gm (61.783 AU)
eccentricity=0.083
period=157390.985 d (430.91 a)
inclination=46.746°
asc_node=252.369°
arg_peri=289.910°
mean_anomaly=259.042°
avg_speed=3.94 km/s
physical_characteristics=yes
dimensions=425–850 km (albedo 0.16-0.04) 335–530 km (albedo 0.25-0.10) [cite journal
author=E. L. Schaller and M. E. Brown
title=Volatile loss and retention on Kuiper belt objects
journal=Astrophysical Journal
volume=659 |pages=I.61–I.64 |year=2007
url=http://www.gps.caltech.edu/~mbrown/papers/ps/volatiles.pdf
accessdate=2008-04-02
doi=10.1086/516709]
mass=0.6–4.8e|20 kg
density=1.5? g/cm³
surface_grav=0.089–0.178 m/s²
escape_velocity=0.195–0.389 km/s
rotation=?
spectral_type=?
abs_magnitude=4.47
albedo=<0.25?
single_temperature=~37–36 K|mp|2004 XR|190 (also written 2004 XR190) is a
trans-Neptunian object located in thescattered disc .Astronomer s led by Lynne Jones of theUniversity of British Columbia made the discovery as part of the Legacy Survey using theCanada-France-Hawaii Telescope (CFHT). The discovery team has temporarily nicknamed the object "Buffy", after the fictional vampire slayer, and proposed a different official name to the IAU.Orbit
Considered a detached object,Jewitt, David, Morbidelli, Alessandro, & Rauer, Heike. (2007). "Trans-Neptunian Objects and Comets: Saas-Fee Advanced Course 35. Swiss Society for Astrophysics and Astronomy". Berlin: Springer. ISBN 3540719571. ] Lykawka, Patryk Sofia & Mukai, Tadashi. (2007). Dynamical classification of trans-neptunian objects: Probing their origin, evolution, and interrelation. "Icarus" Volume 189, Issue 1, July , Pages 213-232. doi|10.1016/j.icarus.2007.01.001.] mp|2004 XR|190 is particularly unusual for two reasons. With an
inclination of 47 degrees, it is the most "tilted" object discovered thus far, traveling further "up and down" than "left to right" around the Sun when viewed edge-on along theecliptic . Second, it has an unusually circular orbit for a scattered disc object. While it has been hypothesized that traditionalScattered Disc Object s (SDOs) have been ejected into their current orbits by gravitational interactions withNeptune , the low eccentricity of its orbit and the distance of its perihelion (SDOs generally have highly eccentric orbits and perihelions less than 38 AU) seems hard to reconcile with such celestial mechanics. This has led to some uncertainty as to the current theoretical understanding of the outerSolar System . The theories include close stellar passages,rogue planet s/planetary embryos in the early Kuiper belt, and resonance interaction with an outward migrating Neptune. TheKozai mechanism is capable of transferring the orbital eccentricity into an elevated inclination. cite journal
author = R. L. Allen, B. Gladman
title = Discovery of a low-eccentricity, high-inclination Kuiper Belt object at 58 AU
journal = The Astrophysical Journal
date = 2006
volume = 640 Discovery paper. [http://arxiv.org/abs/astro-ph/0512430 Preprint] ]Other than
long-period comet s andspace probe s, [cite web
title=Spacecraft escaping the Solar System
publisher=Heavens-Above
author=Chris Peat
url=http://www.heavens-above.com/solar-escape.asp
accessdate=2008-04-03] Buffy is currently the third most distant known object in thesolar system after Eris and Sedna.ize
The object has a diameter estimated at around 500 kilometres, roughly a quarter the size of
Pluto , and orbits between 52 and 62 AU (7.8 and 9.3 Tm) from theSun .References
External links
* [http://cfa-www.harvard.edu/mpec/K05/K05X72.html MPEC circular detailing discovery]
* [http://www.cfeps.astrosci.ca/4b7/ Discovery webpage by research team]
* cite news
url = http://www.newscientist.com/article.ns?id=dn8455&feedId=online-news_rss20
publisher =New Scientist
title = Strange new object found at edge of Solar System
date = 2005-12-13
author = Maggie McKee
* [http://cfht.hawaii.edu/Science/CFHTLS/ Canada-France-Hawaii Telescope Legacy Survey]
* [http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2004XR190;orb=1;view=Far Orbital simulation] from JPL (Java) / [http://ssd.jpl.nasa.gov/horizons.cgi?find_body=1&body_group=sb&sstr=2004XR190 Ephemeris]
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