Despina (moon)
Third-closest inner moon of Neptune, shepherd of the Le Verrier ring.
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Despina is a small, irregularly shaped moon of Neptune discovered in Voyager 2 images from late July 1989.[1][2] Despina's orbit is situated just interior to Neptune's Le Verrier ring, and the moon gravitationally shepherds that ring.[3]
Key facts and history
Its discovery was announced on IAU Circular 4824 on August 2, 1989, with the temporary designation S/1989 N 3.[1][4] The IAU Circular noted that the orbit appeared prograde and nearly circular, though with hints of nonzero eccentricity or inclination.[4] The name Despina was approved by the IAU Executive Committee on September 16, 1991.[5][6] The moon is likely a rubble pile re-accreted from fragments of Neptune's original satellites after Triton's capture.[7]
Despina's orbit lies below Neptune's synchronous orbit radius, causing it to slowly spiral inward due to tidal deceleration.[3] The Voyager 2 probe's narrow-angle camera captured Despina in ten images acquired over a five-day span ending before July 28, 1989.[1][4] Despina has an estimated diameter of about 150 km and lacks any visible evidence of geological activity.[2]
What the cited sources add
That same circular provides the preliminary magnitude estimate that 1989 N 3 was 2.5–3.0 mag fainter than 1989 N 1.[4] The 1991 IAU Circular confirms that the IAU Executive Committee approved the name Despina for satellite 1989 N 3.[6] The IAU Circular 4824 (August 2, 1989) states that the Voyager Imaging Team identified three new satellites of Neptune—1989 N 2, 1989 N 3, and 1989 N 4—from narrow-angle imaging data.[4]
References
- Wikipedia, "Despina (moon)" (CC BY-SA 4.0), which cites: Marsden, "Satellites of Neptune", IAU Circular, August 2, 1989 (we also read that source) en.wikipedia.org
- Wikipedia, "Despina (moon)" (CC BY-SA 4.0), which cites: Karkoschka, "Sizes, shapes, and albedos of the inner satellites of Neptune", Icarus, 2003, p. 400–407 (original not read by us) en.wikipedia.org
- Wikipedia, "Despina (moon)" (CC BY-SA 4.0), which cites: "Despina astronomy", Encyclopedia Britannica (original not read by us) en.wikipedia.org
- Marsden, "Satellites of Neptune", IAU Circular, August 2, 1989. facts only, no text reused. cbat.eps.harvard.edu
- Wikipedia, "Despina (moon)" (CC BY-SA 4.0), which cites: Marsden, "Satellites of Saturn and Neptune", IAU Circular, September 16, 1991 (we also read that source) en.wikipedia.org
- Marsden, "Satellites of Saturn and Neptune", IAU Circular, September 16, 1991. facts only, no text reused. cbat.eps.harvard.edu
- Wikipedia, "Despina (moon)" (CC BY-SA 4.0), which cites: Banfield, "A dynamical history of the inner Neptunian satellites", Icarus, October 1992, p. 390–401 (original not read by us) en.wikipedia.org
Each numbered sentence above was checked against the source it cites before publication. Sentences citing Wikipedia adapt text from the English Wikipedia article Despina (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 Neptune
Elsewhere in Moons of Uranus and Neptune
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: Despina (moon) (CC BY-SA 4.0).
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