24 Themis: Difference between revisions

24 Themis
Discovery
Discovered by	Annibale de Gasparis
Discovery date	April 5, 1853
Designations
Alternative names	1947 BA; 1955 OH
Minor planet category	Main belt (Themis)
Orbital characteristics
	Epoch August 18, 2005 (JD 2453600.5)
Aphelion	530.250 Gm (3.545 AU)
Perihelion	406.202 Gm (2.715 AU)
Semi-major axis	468.226 Gm (3.130 AU)
Eccentricity	0.132
Orbital period (sidereal)	2022.524 d (5.54 a)
Average orbital speed	16.76 km/s
Mean anomaly	185.968°
Inclination	0.760°
Longitude of ascending node	35.992°
Argument of perihelion	107.989°
Physical characteristics
Dimensions	198 km
Mass	1.13±0.43×1019 kg
Mean density	2.78±1.35 g/cm³
Surface gravity	0.15+0.08; −0.07 m/s²
Escape velocity	87+15; −20 m/s
Synodic rotation period	0.34892 d (8 h 23 min)
Albedo	0.067
Temperature	~159 K
Spectral type	C (B-V=0.68)
Absolute magnitude (H)	7.08

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24 Themis (Template:PronEng, [Θέμις] Error: {{Lang-xx}}: text has italic markup (help)) is one of the largest Main belt asteroids. It is also the largest member of the Themistian asteroid family.

It was discovered by Annibale de Gasparis on April 5, 1853. The mass and diameter appearing in the table are from separate sources, and combining them gives an unusually large density, which is most probably wrong. The mass has very likely been overestimated by a factor of at least five times.

It is named after Themis, the personification of divine order, law and custom in Greek mythology.

References

^ ^a ^b ^c ^d ^e Baer, James (1999-06-25). "Astrometric masses of 21 asteroids, and an integrated asteroid ephemeris" (PDF). Celestial Mech Dyn Astr. 100 (2008). Springer Science+Business Media B.V. 2007: 27–42. Retrieved 2008-10-24. {{cite journal}}: Check date values in: |date= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)
^ ^a ^b ^c JPL Small Body Database 24 Themis
^ Asteroid Taxonomy

[astrometric-1] Baer, James (1999-06-25). "Astrometric masses of 21 asteroids, and an integrated asteroid ephemeris" (PDF). Celestial Mech Dyn Astr. 100 (2008). Springer Science+Business Media B.V. 2007: 27–42. Retrieved 2008-10-24. {{cite journal}}: Check date values in: |date= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)

[JPL-2] JPL Small Body Database 24 Themis

[3] Asteroid Taxonomy

[1]

[2]

[3]

@@ Line 17: / Line 17: @@
  | mean_anomaly=185.968°
  | avg_speed=16.76 km/[[second|s]]
- | dimensions=198 km {{MPCit_JPL|24|<sup>[1<nowiki>]</nowiki></sup>}}
+ | dimensions=198 km <ref name="astrometric">{{cite journal
+  | last = Baer
- | mass=5.75±2.51{{e|19}} [[kilogram|kg]] <ref>[http://www.psi.edu/pds/asteroid/EAR_A_5_DDR_ASTEROID_DENSITIES_V1_1 Index of /pds/asteroid/EAR_A_5_DDR_ASTEROID_DENSITIES_V1_1<!-- Bot generated title -->]</ref>
+  | first = James
- | density=14±6 g/[[cubic centimetre|cm³]] ''doubtful''
+  | authorlink = James Baer
- | surface_grav=0.39±0.27 m/s²
+  | coauthors = [[Steven R. Chesley]]
- | escape_velocity=0.88±0.22 km/s
+  | title = Astrometric masses of 21 asteroids, and an integrated asteroid ephemeris
- | rotation=0.34892 d (8 h 23 min) <ref>[http://www.psi.edu/pds/archive/lc.html]{{Dead link|date=March 2008}}</ref><ref>[http://www.astrosurf.com/aude-old/map_files/AstVarMAP01-2003.htm]{{Dead link|date=March 2008}}</ref>
+  | journal = Celestial Mech Dyn Astr
- | spectral_type=[[C-type asteroid|C]] <ref>[http://pdssbn.astro.umd.edu/SBNcgi/sbdbatt?objnum=32124 Small Bodies Attributes Utility Results<!-- Bot generated title -->]</ref> (B-V=0.68)
+  | volume = 100
- | abs_magnitude=7.08
+  | issue = 2008
- | albedo=0.067 <ref>[http://ssd.jpl.nasa.gov/cgi-bin/da Page Modified<!-- Bot generated title -->]</ref>
+  | pages = 27-42
+  | publisher = Springer Science+Business Media B.V. 2007
+  | date = [[1999-06-25]]
+  | url = http://www.springerlink.com/content/h747307j43863228/fulltext.pdf
+  | format = [[PDF]]
+  | accessdate = 2008-10-24 }}</ref>
+ | mass=1.13±0.43{{e|19}} [[kilogram|kg]] <ref name="astrometric"></ref>
+ | density=2.78±1.35 g/[[cubic centimetre|cm³]] <ref name="astrometric"></ref>
+ | surface_grav=0.15{{±|0.08|0.07}} m/s² <ref name="astrometric"></ref>
+ | escape_velocity=87{{±|15|20}} m/s <ref name="astrometric"></ref>
+ | rotation=0.34892 d (8 h 23 min) <ref name="JPL">[http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=24 JPL Small Body Database 24 Themis]</ref>
+ | spectral_type=[[C-type asteroid|C]] <ref>[http://www.psi.edu/pds/resource/taxonomy.html Asteroid Taxonomy]</ref> (B-V=0.68)
+ | abs_magnitude=7.08 <ref name="JPL"></ref>
+ | albedo=0.067 <ref name="JPL"></ref>
  | single_temperature=~159 [[kelvin|K]]}}
 '''24 Themis''' ({{pronEng|ˈθiːm<s>ɪ</s>s}}, {{lang-gr|''Θέμις}})'' is one of the largest [[Main belt]] [[asteroid]]s. It is also the largest member of the [[Themis family|Themistian asteroid family]].