Linus (moon)

Infobox Planet | discovery=yes | physical_characteristics = yes | bgcolour=#A0FFA0 | minorplanet=yes | width=28em
name=Linus
discovery_ref = [http://cfa-www.harvard.edu/iauc/07700/07703.html IAUC 7703] ]
discoverer=Jean-Luc Margot and Michael E. Brown
discovered=August 29, 2001
mp_name=S/2001 (22) 1
mp_category=Main belt
semimajor= 1065 ± 8 km [http://astro.berkeley.edu/~fmarchis/Science/Asteroids/Kalliope.html synthesis of several observations] including recent ones with the VLT 8m telescope.] cite journal | author= J.L. Margot & M.E. Brown| title= "A Low-Density M-type Asteroid in the Main Belt"| journal= Science| year= 2003| volume= 300| pages= 1939| url= http://www.sciencemag.org/cgi/content/full/300/5627/1939?ijkey=ikdx9/Weub/52&keytype=ref&siteid=sci| doi= 10.1126/science.1085844| pmid= 12817147] cite journal | author= F. Marchis et al| title= "A three-dimensional solution for the orbit of the asteroidal satellite of 22 Kalliope"| journal= Icarus| year= 2003| volume= 165| pages= 112| url=http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2003Icar..165..112M&db_key=AST&data_type=HTML&format=&high=444b66a47d11635| doi= 10.1016/S0019-1035(03)00195-7]
eccentricity=< 0.005
period=3.590 ± 0.001 d
avg_speed=21.5 m/s
inclination=9 ± 1°
(with respect to Kalliope equator)
satellite_of = 22 Kalliope
dimensions=38 ± 6 km Assuming the same albedo as Kalliope.]
mass=~6e|16 kg "(estimate)"
escape_velocity=~20 m/s "(estimate)"
rotation = unknown, probably synchronous Based on a rough tidal locking timescale of several tens of My.]
axial_tilt = unknown, zero expected
temperatures=yes
temp_name1 = Kelvin
mean_temp_1 = ~161
max_temp_1 = 240
temp_name2 = Celsius
max_temp_2 = -32°
abs_magnitude=9.7

(22) Kalliope I Linus is an asteroid moon that orbits the large M-type asteroid 22 Kalliope.

With an estimated 38±6 km diameter , Linus is very large compared to most asteroid moons, and in fact would be a sizeable asteroid by itself. The only known larger moons in the Main belt are the two components of the double asteroid 90 Antiope.

On August 29, 2001, astronomers Jean-Luc Margot and Michael E. Brown discovered Linus orbiting 22 Kalliope with the Keck telescope. Another team also detected the moon with the Canada-France-Hawaii Telescope on September 2, 2001. Both telescopes are on Mauna Kea. It received the provisional designation S/2001 (22) 1, and was named on August 8, 2003 after the mythological Linus, son of the muse Calliope and the inventor of melody and rhythm.

It has been estimated that Linus' orbit precesses at quite a rapid rate, making one cycle in several years. This is attributed primarily to the non-spherical shape of Kalliope . Linus's brightness has varied appreciably between observations, which may indicate that its shape is elongated .

Linus may have formed out of impact ejecta from a collision with Kalliope or a fragment captured after disruption of a parent asteroid (a proto-Kalliope).

References

External links

* [http://cfa-www.harvard.edu/iauc/07700/07703.html IAUC 7703] , announcing Linus' discovery
* [http://cfa-www.harvard.edu/iauc/08100/08177.html IAUC 8177] , announcing Linus' naming
* [http://www.astro.cornell.edu/~jlm/publications.html Link to the Linus discovery paper , "A Low-Density M-type Asteroid in the Main Belt"]
* [http://astron.berkeley.edu/~fmarchis/Science/Asteroids/#Kalliope Kalliope and Linus] very well resolved with the 8m VLT
* [http://www.eso.org/outreach/press-rel/pr-2004/pr-21-04.html#phot-24j-04 orbit diagram for Linus]
* [http://astron.berkeley.edu/~fmarchis/Science/Asteroids/Kalliope.html Information on Kalliope, Linus' orbit and several images]
* [http://occsec.wellington.net.nz/planet/2004/updates/040708_22_1819_u.htm A different VLT image of Kalliope and Linus]
* [http://www.monde.de/planetoiden-hauptguertel.html another image of Kalliope and Linus]