(177) Irma
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Asteroid (177) Irma |
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| Properties of the orbit ( animation ) | |
| Orbit type | Middle main belt |
| Major semi-axis | 2.767 AU |
| eccentricity | 0.239 |
| Perihelion - aphelion | 2.106 AU - 3.428 AU |
| Inclination of the orbit plane | 1.4 ° |
| Length of the ascending node | 347.6 ° |
| Argument of the periapsis | 38.4 ° |
| Time of passage of the perihelion | June 10, 2011 |
| Sidereal period | 4 a 220 d |
| Mean orbital velocity | 17.6 km / s |
| Physical Properties | |
| Medium diameter | 73 ± 1.6 km |
| Albedo | 0.0527 |
| Rotation period | 14 h 12 min |
| Absolute brightness | 9.49 likes |
| Spectral class | C. |
| history | |
| Explorer | PP Henry |
| Date of discovery | November 5, 1877 |
| Source: Unless otherwise stated, the data comes from JPL Small-Body Database Browser . The affiliation to an asteroid family is automatically determined from the AstDyS-2 database . Please also note the note on asteroid items. | |
(177) Irma is an asteroid of the main asteroid belt discovered by Paul Pierre Henry on November 5, 1877 . It is not known what the name is derived from.
Irma moves between 2.1146 ( perihelion ) AU to 3.4258 AU ( aphelion ) in 4.611 years around the sun . The orbit is 1.3927 ° inclined to the ecliptic , the orbital eccentricity is 0.2367. Irma has a diameter of 73 km. It has a dark carbon-rich surface with an albedo of 0.053. It rotates around its own axis in around 14 hours and 12 minutes.