7066 Nessus

Infobox Planet | minorplanet = yes | width = 25em | bgcolour = #FFFFC0
name=7066 Nessus
discovery=yes
discoverer=David L. Rabinowitz
discovered=April 26, 1993
alt_names=mp|1993 HA|2
mp_category=Centaur
orbit_ref=cite web
date=2004-05-26 last obs
title=JPL Small-Body Database Browser: 7066 Nessus (1993 HA2)
url=http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=Nessus
accessdate=2008-09-05]
epoch=December 31, 2006 (JD 2454100.5)
semimajor=3688.309 Gm (24.655 AU)
perihelion=1769.167 Gm (11.826 AU)
aphelion=5607.451 Gm (37.483 AU)
eccentricity=0.520
period=44714.802 d (122.42 a)
inclination=15.647°
asc_node=31.216°
arg_peri=170.814°
mean_anomaly=43.762°
avg_speed=5.57 km/s
physical_characteristics=yes
dimensions=60 kmcite web
date=22 August 2008
title=List of Known Trans-Neptunian Objects
publisher=Johnston's Archive
author=Wm. Robert Johnston
url=http://www.johnstonsarchive.net/astro/tnoslist.html
accessdate=2008-09-05]
mass=~1.6e|17 kg
density=2.0? g/cm³
surface_grav=~0.0148 m/s²
escape_velocity=~0.0280 km/s
sidereal_day=? d
axial_tilt=?° | pole_ecliptic_lat=? | pole_ecliptic_lon=?
spectral_type=?
abs_magnitude=9.6
albedo=0.10?
single_temperature=~56 K

7066 Nessus (pronEng|ˈnɛsəs, from _gr. "Νέσσος") is a centaur (a type of icy planetoid) that was discovered by David L. Rabinowitz, working with Spacewatch, at Kitt Peak on 26 April, 1993. It was the second centaur found by him (5145 Pholus being his previous find), and the third centaur discovery (2060 Chiron was the first). It was officially announced on May 13, 1993 in IAUC 5789 with designation mp|1993 HA|2.

Orbit

7066 Nessus has an orbital period of 122.4 years, an eccentricity of 0.52 and an inclination to the ecliptic of 15.6 degrees. At perihelion, it moves closer to the Sun than Uranus, while at aphelion it moves out past the orbit of Neptune.

The orbits of centaurs are unstable due to interactions with the giant planets. Nessus is estimated to have a relatively long orbital half-life of about 4.9 Myr.cite journal
last=Horner |first= J.
coauthors=Evans, N.W.; Bailey, M. E.
title=Simulations of the Population of Centaurs I: The Bulk Statistics
year=2004
url=http://arxiv.org/abs/astro-ph?papernum=0407400
accessdate=2008-09-01 ]

Name

The naming of Nessus is an interesting break from tradition. Three astrologers were independently studying mp|1993 HA|2 to see if it had any astrological significance. These were Zane B Stein in the USA, and Dieter Koch and Robert Von Heeren in Germany. In separate letters to astronomers David L. Rabinowitz, Alan Stern, Jim Scotti and Dr. Brian Marsden, these astrologers suggested to name the body after the mythological centaur Nessus.

Dr. Marsden gave his support to the suggested name, and recommended it to the IAU. This name was approved, and mp|1993 HA|2 was officially renamed 7066 Nessus on April 22 1997. This naming was an unprecedented cooperation between astrologers and astronomers.

References

External links

* [http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=Nessus;orb=1;view=Far Orbital simulation] from JPL (Java) / [http://ssd.jpl.nasa.gov/horizons.cgi?find_body=1&body_group=sb&sstr=Nessus Ephemeris]
* [http://spacewatch.lpl.arizona.edu/nea.html Spacewatch]
* [http://www.hohmanntransfer.com/cat/an02.htm Asteroid/Comet connection]
* [http://www.centaurs.info/menu/index.htm?page=/menu/home.htm The Centaur Research Project]
*an account of [http://www.zanestein.com/page4_2.htm the naming]
* [http://www.zanestein.com/nessus.htm Nessus in astrology]
* [http://www.zanestein.com/keywords.html#Nessus Astrological keywords for Nessus]