190 Ismene
Encyclopedia
| Orbital characteristics [ftp://ftp.lowell.edu/pub/elgb/astorb.html 1] | |
|---|---|
| Orbit Orbit In physics, an orbit is the gravitationally curved path of an object around a point in space, for example the orbit of a planet around the center of a star system, such as the Solar System... type |
Main belt Asteroid belt The asteroid belt is the region of the Solar System located roughly between the orbits of the planets Mars and Jupiter. It is occupied by numerous irregularly shaped bodies called asteroids or minor planets... (Hilda) |
| Semimajor axis | 3.984 AU Astronomical unit An astronomical unit is a unit of length equal to about or approximately the mean Earth–Sun distance.... |
| Perihelion distance | 3.319 AU Astronomical unit An astronomical unit is a unit of length equal to about or approximately the mean Earth–Sun distance.... |
| Aphelion distance | 4.648 AU Astronomical unit An astronomical unit is a unit of length equal to about or approximately the mean Earth–Sun distance.... |
| Orbital period Orbital period The orbital period is the time taken for a given object to make one complete orbit about another object.When mentioned without further qualification in astronomy this refers to the sidereal period of an astronomical object, which is calculated with respect to the stars.There are several kinds of... |
7.95 years |
| Inclination Inclination Inclination in general is the angle between a reference plane and another plane or axis of direction.-Orbits:The inclination is one of the six orbital parameters describing the shape and orientation of a celestial orbit... |
6.17° |
| Eccentricity | 0.167 |
| Physical characteristics | |
| Diameter Diameter In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints are on the circle. The diameters are the longest chords of the circle... 2 |
164.4 km |
| Rotation period Rotation period The rotation period of an astronomical object is the time it takes to complete one revolution around its axis of rotation relative to the background stars... |
6.52 hours 3 |
| Spectral class 2 | P P-type asteroid P-type asteroids have low albedo and a featureless reddish electromagnetic spectrum. It has been suggested that they have a composition of organic rich silicates, carbon and anhydrous silicates, possibly with water ice in their interior... |
| Abs. magnitude Absolute magnitude Absolute magnitude is the measure of a celestial object's intrinsic brightness. it is also the apparent magnitude a star would have if it were 32.6 light years away from Earth... [ftp://ftp.lowell.edu/pub/elgb/astorb.html 1] |
7.59 |
| Albedo Albedo Albedo , or reflection coefficient, is the diffuse reflectivity or reflecting power of a surface. It is defined as the ratio of reflected radiation from the surface to incident radiation upon it... 2 |
0.058 |
| History 4 | |
| Discoverer | C. H. F. Peters Christian Heinrich Friedrich Peters Christian Heinrich Friedrich Peters was a German-American astronomer, and one of the first to discover asteroids.... , 1878 |
190 Ismene is a very large main belt
Asteroid belt
The asteroid belt is the region of the Solar System located roughly between the orbits of the planets Mars and Jupiter. It is occupied by numerous irregularly shaped bodies called asteroids or minor planets...
asteroid
Asteroid
Asteroids are a class of small Solar System bodies in orbit around the Sun. They have also been called planetoids, especially the larger ones...
. Being a P-type asteroid
P-type asteroid
P-type asteroids have low albedo and a featureless reddish electromagnetic spectrum. It has been suggested that they have a composition of organic rich silicates, carbon and anhydrous silicates, possibly with water ice in their interior...
, it has a very dark surface and may contain water.
Ismene orbit
Orbit
In physics, an orbit is the gravitationally curved path of an object around a point in space, for example the orbit of a planet around the center of a star system, such as the Solar System...
s near the outer edge of the asteroid belt. It is one of the Hilda asteroids, which are locked in 3:2 resonance
Orbital resonance
In celestial mechanics, an orbital resonance occurs when two orbiting bodies exert a regular, periodic gravitational influence on each other, usually due to their orbital periods being related by a ratio of two small integers. Orbital resonances greatly enhance the mutual gravitational influence of...
with the planet
Planet
A planet is a celestial body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared its neighbouring region of planetesimals.The term planet is ancient, with ties to history, science,...
Jupiter
Jupiter
Jupiter is the fifth planet from the Sun and the largest planet within the Solar System. It is a gas giant with mass one-thousandth that of the Sun but is two and a half times the mass of all the other planets in our Solar System combined. Jupiter is classified as a gas giant along with Saturn,...
.
It was discovered by C. H. F. Peters
Christian Heinrich Friedrich Peters
Christian Heinrich Friedrich Peters was a German-American astronomer, and one of the first to discover asteroids....
on September 22, 1878 in Clinton, New York
Clinton, Oneida County, New York
Clinton is a village in Oneida County, New York, United States. The population was 1,952 at the 2000 census. It was named for George Clinton, a royal governor of the colony of New York....
and named after Ismene
Ismene
Ismene is the name of two women of Greek mythology. The more famous is a daughter and half-sister of Oedipus, daughter and granddaughter of Jocasta, and sister of Antigone, Eteocles, and Polynices. She appears in several plays of Sophocles: at the end of Oedipus the King, in Oedipus at Colonus and...
, the sister of Antigone
Antigone
In Greek mythology, Antigone is the daughter of Oedipus and Jocasta, Oedipus' mother. The name may be taken to mean "unbending", coming from "anti-" and "-gon / -gony" , but has also been suggested to mean "opposed to motherhood", "in place of a mother", or "anti-generative", based from the root...
in Greek mythology
Greek mythology
Greek mythology is the body of myths and legends belonging to the ancient Greeks, concerning their gods and heroes, the nature of the world, and the origins and significance of their own cult and ritual practices. They were a part of religion in ancient Greece...
.