| Minorplanet | yes |
|---|---|
| Background |
|
| Discoverer | Henri Joseph Perrotin |
| Discovered | 21 September 1875 |
| Mpc name | (149) Medusa |
| Alt names | A875 SA; 1905 BA; 1906 HB |
| Named after | Medusa |
| Pronounced | /mᵻdjuːsə/[1] |
| Mp category | Main belt |
| Epoch | 31 July 2016 (JD 2457600.5) |
| Semimajor | 2.17472 AU (325.33 Gm) |
| Perihelion | 2.03252 AU (304.06 Gm) |
| Aphelion | 2.3169 AU (346.60 Gm) |
| Eccentricity | 0.065386 |
| Period | 1,171.4 days |
| Inclination | 0.93927° |
| Asc node | 159.615° |
| Arg peri | 250.609° |
| Mean anomaly | 280.686° |
| Avg speed | 20.18 km/s |
| Dimensions | 19.75 ± 0.9 km |
| Mass | 8.0×1015 kg |
| Density | 2.0 g/cm3 |
| Surface grav | 0.0055 m/s2 |
| Escape velocity | 0.0104 km/s |
| Abs magnitude | 10.79 |
| Rotation | 26.023 h[2] 26.038 h[3] |
| Albedo | 0.2334 ± 0.022 |
| Single temperature | ~189 K |
| Mean motion | / day |
| Observation arc | 124.55 yr (45493 d) |
| Uncertainty | 0 |
| Moid | 1.04123 AU (155.77 Gm) |
| Jupiter moid | 2.87692 AU (430.38 Gm) |
| Tisserand | 3.683 |
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 1,171.4 days and an eccentricity of 0.065. The orbital plane is tilted slightly at an angle of 0.94° to the plane of the ecliptic.[4]
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.[3]
References
- ^
- ^ Yeomans, Donald K., "149 Medusa", JPL Small-Body Database Browser, NASA Jet Propulsion Laboratory, retrieved 12 May 2016
- ^ Pilcher, Frederick (April 2011), "Rotation Period Determinations for 25 Phocaea, 140 Siwa, 149 Medusa 186 Celuta, 475 Ocllo, 574 Reginhild, and 603 Timandra", The Minor Planet Bulletin. Vol. 38, no. 2, pp. 76–78, Bibcode:2011MPBu...38...76P
- ^ "The Asteroid Orbital Elements Database". astorb. Lowell Observatory