124 Alkeste

Alkeste (minor planet designation: 124 Alkeste) is a main-belt asteroid, and it is an S-type (silicaceous) in composition. C.H.F. Peters discovered the asteroid on August 23, 1872, from the observatory at Hamilton College, New York State. The name was chosen by Adelinde Weiss, wife of the astronomer Edmund Weiss, and refers to Alcestis, a woman in Greek mythology.[4]

The observed shape of Alkeste from a stellar occultation in 2003
124 Alkeste
Discovery
Discovered byChristian Heinrich Friedrich Peters
Discovery date23 August 1872
Designations
(124) Alkeste
Pronunciation/ælˈkɛstiː/[1]
Named after
Alcestis
A872 QA
Main belt
Orbital characteristics[2]
Epoch 31 July 2016 (JD 2457600.5)
Uncertainty parameter 0
Observation arc143.65 yr (52468 d)
Aphelion2.8288 AU (423.18 Gm)
Perihelion2.43166 AU (363.771 Gm)
2.63022 AU (393.475 Gm)
Eccentricity0.075491
4.27 yr (1558.1 d)
18.34 km/s
343.779°
0° 13m 51.816s / day
Inclination2.9573°
187.991°
61.413°
Earth MOID1.41927 AU (212.320 Gm)
Jupiter MOID2.17851 AU (325.900 Gm)
TJupiter3.394
Physical characteristics
Dimensions88.65±1.65 km
76.36±1.7 km
Mass4.7×1017 kg
Equatorial surface gravity
0.0214 m/s²
Equatorial escape velocity
0.0404 km/s
9.921 h (0.4134 d)
0.1728±0.008
Temperature~172 K
S
8.11,[2] 8.09[3]

    A 20 chord stellar occultation by Alkeste was observed when the asteroid passed in front of the third magnitude star Beta Virginis on June 24, 2003. The event was visible from Australia and New Zealand.[5]

    The asteroid has been observed in 3 more stellar occultation events.[6]

    Photometric observations of this asteroid in 2016 produced lightcurves indicating a rotation period of 9.9 hours with an amplitude variation of 0.18 in magnitude. This result matched previous determinations of the spin rate. The lightcurve was found to vary over the observation period as the viewing angle changed, suggesting the shadowing of topographic features.[7]

    References
    1. 'Alceste' in Noah Webster (1884) A Practical Dictionary of the English Language
    2. Yeomans, Donald K., "124 Alkeste", JPL Small-Body Database Browser, NASA Jet Propulsion Laboratory, retrieved 12 May 2016.
    3. Warner, Brian D. (December 2007), "Initial Results of a Dedicated H-G Project", The Minor Planet Bulletin, vol. 34, pp. 113–119, Bibcode:2007MPBu...34..113W.
    4. Schmadel, Lutz D. (2003). Dictionary of Minor Planet Names. Springer Science & Business Media. p. 27. ISBN 978-3-540-00238-3.
    5. Occultation by (124) Alkeste - 2003 Jun 24, Occultation Section, Royal Astronomical Society of New Zealand, 23 May 2003, retrieved 19 January 2018.
    6. "Asteroid Data Sets". sbn.psi.edu. Retrieved 19 May 2018.
    7. Pilcher, Frederick (October 2016), "Three Asteroids with Changing Lightcurves: 124 Alkeste, 465 Alekto, and 569 Misa", The Minor Planet Bulletin, 43 (4): 296–299, Bibcode:2016MPBu...43..296P.


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