51 Nemausa

51 Nemausa
Discovery
Discovered byJ. Laurent
Discovery siteNîmes
Discovery dateJanuary 22, 1858
Designations
(51) Nemausa
Pronunciation/nɛˈmɔːsə/[1]
Named after
Nemausus
Main belt
AdjectivesNemausian /nɛˈmɔːsiən/
Orbital characteristics
Epoch December 31, 2006 (JD 2454100.5)
Aphelion2.523 AU (377.381 Gm)
Perihelion2.208 AU (330.360 Gm)
2.365 AU (353.871 Gm)
Eccentricity0.066
3.64 a (1328.853 d)
316.668°
Inclination9.972°
176.168°
2.820°
Physical characteristics
Dimensionsc/a = 0.77±0.04[2]
170×136 km[3]
150±3 km[2]
Mass(3.9±1.6)×1018 kg[2]
(2.48±0.86)×1018 kg[4]
Mean density
2.2±0.9 g/cm3[2]
1.43±0.50 g/cm3[4]
0.09 (calculated)[2]
0.093[5]
G
7.35

51 Nemausa is a large main-belt asteroid that was discovered on January 22, 1858, by Joseph Jean Pierre Laurent. Laurent made the discovery from the private observatory of Benjamin Valz in Nîmes, France. The house, at 32 rue Nationale in Nîmes, has a plaque commemorating the discovery. With Laurent's permission, Valz named the asteroid after the Celtic god Nemausus, the patron god and namesake of Nîmes during Roman times.[6]

Based upon its spectrum, this is listed as a C-type asteroid in the Tholen classification taxonomy, and as a Cgh by Bus and Binzel (2002). This indicates a composition similar to carbonaceous chondrite meteorites. Absorption features in the spectrum indicate the presence of phyllosilicates.[7] It may have a water content of about 14%.[8]

The first stellar occultation was observed on August 17, 1979, from the Gissar and Alma-Ata observatories produced two chords which were used to estimate a diameter of 150 km for the asteroid.[9] This is close to the present-day estimate of 147.9 km. Since then 51 Nemausa has been observed 20 times[10] in stellar occultation.

Light curve inversion model DAMIT 1065 is a good match to a seven-chord occultation observed on 3 September 2016, from which an equivalent mean diameter of 146.4 km, and an equivalent Surface mean diameter of 150.3 km was obtained.

Lightcurve data suggests that it may have a small moon.[11] Nemausa has been studied by radar.[12]

Images related to 51 Nemausa
  • A light-curve Inversion model (DAMIT 1065) and a seven-chord occultation of 51 Nemausa
    A light-curve Inversion model (DAMIT 1065) and a seven-chord occultation of 51 Nemausa
  • Hello world
    Chart dated 22 January 1858
  • Goodbye world
    Detail of handwritten legend at top ("J. Laurent")
  1. ^ John Craig (1869) The Universal English Dictionary
  2. ^ a b c d e P. Vernazza et al. (2021) VLT/SPHERE imaging survey of the largest main-belt asteroids: Final results and synthesis. Astronomy & Astrophysics 54, A56
  3. ^ "Diameters". Astronomical Applications Department of the U.S. Naval Observatory. Archived from the original on 27 September 2011. Retrieved 23 May 2008.
  4. ^ a b Cite error: The named reference Carry2012 was invoked but never defined (see the help page).
  5. ^ Asteroid Data Sets Archived 2009-12-17 at the Wayback Machine
  6. ^ Schmadel, Lutz D. (2003). Dictionary of Minor Planet Names. Springer Science & Business Media. p. 20. ISBN 978-3-540-00238-3.
  7. ^ Cite error: The named reference Reynolds2009 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference water2002 was invoked but never defined (see the help page).
  9. ^  
  10. ^ "Asteroid Data Sets". sbn.psi.edu. Retrieved 27 May 2018.
  11. ^ Other reports of asteroid/TNO companions
  12. ^ Cite error: The named reference detected was invoked but never defined (see the help page).