Themisto (moon)
Last updated
Themisto is a small moon of Jupiter with a diameter of about 9 km, assuming an albedo of 0.04.[1] It has a red color in the visible spectrum, similar to D-type asteroids.[1][2] Themisto was first observed in 1975 and then rediscovered in 2000 before being confirmed as the same object.[3][4]
Key facts and history
Charles T. Kowal and Elizabeth Roemer first discovered Themisto on 30 September 1975, and it was reported on 3 October 1975 with the designation S/1975 J 1.[3][5] A backward integration of the 2000 orbit by G. V. Williams proved the subarcmin agreement with the 1975 observations, confirming they were the same moon.[6] An earlier observation on 6 August 2000 by Brett J. Gladman and colleagues was correlated with the rediscovery but had not been published as an IAU Circular.[4] Themisto is colored red in the visible spectrum, with measured color indices of B−V=0.83, V−R=0.46, and V−I=0.94.[2]
Because the NEOWISE observations were poorly timed, the actual albedo of Themisto could not be determined.[1]
What the cited sources add
That same circular notes that Marsden suggested the possibility of identification with the lost satellite S/1975 J 1, which was proven by Williams from subarcmin agreement of a backward integration.[6] IAUC 7998 from 22 October 2002 lists the official naming of Themisto as Jupiter XVIII, with the designation S/1975 J 1 = S/2000 J 1.[7]
References
- Wikipedia, "Themisto (moon)" (CC BY-SA 4.0), which cites: Sheppard, "Scott S. Sheppard - Jupiter Moons", Department of Terrestrial Magnetism; Grav, "NEOWISE: Observations of the Irregular Satellites of Jupiter and Saturn", The Astrophysical Journal, August 2015, p. 9 (original not read by us) en.wikipedia.org
- Wikipedia, "Themisto (moon)" (CC BY-SA 4.0), which cites: Grav, "Photometric survey of the irregular satellites", Icarus, 2003, p. 33–45 (original not read by us) en.wikipedia.org
- Wikipedia, "Themisto (moon)" (CC BY-SA 4.0), which cites: Brian G. Marsden, "IAUC 2845: Probable New Satellite of Jupiter", International Astronomical Union Central Bureau for Astronomical Telegrams, 3 October 1975 (we also read that source) en.wikipedia.org
- Wikipedia, "Themisto (moon)" (CC BY-SA 4.0), which cites: Brian G. Marsden, "IAUC 7525: S/1975 J 1 = S/2000 J 1", International Astronomical Union Central Bureau for Astronomical Telegrams, 25 November 2000; "MPEC 2000-Y16: S/1975 J 1 = S/2000 J 1, S/1999 J 1", International Astronomical Union Minor Planet Center, 19 December 2000 (we also read that source) en.wikipedia.org
- Brian G. Marsden, "IAUC 2845: Probable New Satellite of Jupiter", International Astronomical Union Central Bureau for Astronomical Telegrams, 3 October 1975. facts only, no text reused. cbat.eps.harvard.edu
- Brian G. Marsden, "IAUC 7525: S/1975 J 1 = S/2000 J 1", International Astronomical Union Central Bureau for Astronomical Telegrams, 25 November 2000. facts only, no text reused. cbat.eps.harvard.edu
- Daniel W. E. Green, "IAUC 7998: Satellites of Jupiter", International Astronomical Union, 22 October 2002. facts only, no text reused. cbat.eps.harvard.edu
Each numbered sentence above was checked against the source it cites before publication. Sentences citing Wikipedia adapt text from the English Wikipedia article Themisto (moon) (contributors), used under CC BY-SA 4.0; this entry is available under the same licence. Other sources were used for facts only; no text or images are copied from them.
More in Moons of Jupiter
Sources
Compiled from Wikipedia and the sources listed below. Text from Wikipedia is available under CC BY-SA 4.0; this entry is adapted from it.
- Wikipedia: Themisto (moon) (CC BY-SA 4.0).
Spotted an error? Know more?
Reader corrections go straight into our review queue. Suggest an edit · How this site is sourced