149 Medusa

149 Medusa
A three-dimensional model of 149 Medusa based on its light curve.
Discovery[1]
Discovered byHenri Joseph Perrotin
Discovery date21 September 1875
Designations
(149) Medusa
Pronunciation/mɪˈdjsə/[2]
Named after
Medusa
A875 SA; 1905 BA;
1906 HB
Main belt
Orbital characteristics[3][4]
Epoch 31 July 2016 (JD 2457600.5)
Uncertainty parameter 0
Observation arc124.55 yr (45493 d)
Aphelion2.32 AU (346.60 Gm)
Perihelion2.03 AU (304.06 Gm)
2.17 AU (325.33 Gm)
Eccentricity0.065386
3.21 yr (1,171.4 d)
20.18 km/s
280.686°
0° 18m 26.374s / day
Inclination0.93927°
159.615°
250.609°
Earth MOID1.04 AU (155.77 Gm)
Jupiter MOID2.88 AU (430.38 Gm)
TJupiter3.683
Physical characteristics
Dimensions19.75±0.9 km
Mass8.0×1015 kg
Mean density
2.0 g/cm3
Equatorial surface gravity
0.0055 m/s2
Equatorial escape velocity
0.0104 km/s
26.023 h (1.0843 d)[4]
26.038 h[5]
0.2334±0.022
Temperature~189 K
S
10.79

149 Medusa is a bright-coloured, stony main-belt asteroid that was discovered by French astronomer J. Perrotin on September 21, 1875, and named after the Gorgon Medusa, a snake-haired monster in Greek mythology. It is orbiting the Sun at a distance of 2.17 AU with a period of 3.21 years and an eccentricity of 0.065. The orbital plane is tilted slightly at an angle of 0.94° to the plane of the ecliptic.[3]

When it was discovered, Medusa was by far the smallest asteroid found (although this was not known at that time). Since then, many thousands of smaller asteroids have been found. It was also the closest asteroid to the Sun discovered up to that point, beating the long-held record of 8 Flora. It remained the closest asteroid to the Sun until 433 Eros and 434 Hungaria were found in 1898, leading to the discovery of two new families of asteroids inward from the 4:1 Kirkwood gap which forms the boundary of the main belt.[citation needed]

Photometric observations of this asteroid at the Organ Mesa Observatory in Las Cruces, New Mexico, during 2010 gave a light curve with a rather long rotation period of 26.038 ± 0.002 hours and a brightness variation of 0.56 ± 0.03 in magnitude.[5]

  1. ^ Cite error: The named reference MPC-disc was invoked but never defined (see the help page).
  2. ^ "Medusa". Oxford English Dictionary (Online ed.). Oxford University Press. (Subscription or participating institution membership required.)
  3. ^ a b "The Asteroid Orbital Elements Database". astorb. Lowell Observatory.
  4. ^ a b Cite error: The named reference JPL was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Pilcher2011 was invoked but never defined (see the help page).