NationMaster - Encyclopedia: 121 Hermione

121 Hermione is a very large and dark main belt asteroid. It is probably composed of carbonaceous materials. In physics, an orbit is the path that an object makes, around another object, whilst under the influence of a source of centripetal force, such as gravity. ... The asteroid belt is a region of the solar system falling roughly between the planets Mars and Jupiter where the greatest concentration of asteroid orbits can be found. ... 65 Cybele (sib-a-lee) is one of the largest asteroids in the main belt. ... In geometry, the semi-major axis (also semimajor axis) a applies to ellipses and hyperbolas. ... The astronomical unit (AU or au or a. ... This article is about several astronomical terms (apogee & perigee, aphelion & perihelion, generic equivalents based on apsis, and related but rarer terms. ... The astronomical unit (AU or au or a. ... This article is about several astronomical terms (apogee & perigee, aphelion & perihelion, generic equivalents based on apsis, and related but rarer terms. ... The astronomical unit (AU or au or a. ... The orbital period is the time it takes a planet (or another object) to make one full orbit. ... A year is the time between two recurrences of an event related to the orbit of the Earth around the Sun. ... Inclination is one of the six orbital parameters describing the shape and orientation of a celestial orbit and is the angular distance of the orbital plane from the plane of the reference (usually planets equator or the ecliptic), stated in degrees. ... In astrodynamics, under standard assumptions any orbit must be of conic section shape. ... For the geometric term, see diameter. ... A kilometre (American spelling: kilometer, symbol: km) is a unit of length equal to 1000 metres (from the Greek words khilia = thousand and metro = count/measure). ... Mass is a property of physical objects that, roughly speaking, measures the amount of matter they contain. ... The international prototype, made of platinum-iridium, which is kept at the BIPM under conditions specified by the 1st CGPM in 1889. ... Density (symbol: Ï - Greek: rho) is a measure of mass per unit of volume. ... The gram or gramme, symbol g, is a unit of mass, and is defined in the SI system of units as one one-thousandth of a kilogram (i. ... A cubic centimetre (cm3) is an SI derived unit of volume, equal to the volume of a cube with side length of 1 centi metre. ... In astronomy, a rotation period is the time an astronomical object takes to complete one revolution around its rotation axis. ... The hour was originally defined in Egypt as 1/24 of a day, based on their duo-decimal numbering system (which counted finger joints on each hand). ... In astronomy the term spectral class refers to classifying objects according to their spectral lines, which indicate an objects chemical composition. ... C-type asteroids are carbonaceous asteroids. ... In astronomy, absolute magnitude is the apparent magnitude, m, an object would have if it were at a standardized distance away. ... The albedo is a measure of reflectivity of a surface or body. ... James Craig Watson (January 28, 1838 – November 22, 1880) was a Canadian-American astronomer born in the village of Fingal in Ontario, Canada. ... 1872 was a leap year starting on Monday (see link for calendar). ... The asteroid belt is a region of the solar system falling roughly between the planets Mars and Jupiter where the greatest concentration of asteroid orbits can be found. ... An asteroid is a small, solid object in our Solar System, orbiting the Sun. ... Carbonate is an anion with a charge of -2 and an empirical formula of CO32-. For an aqueous solution, carbonate exists in three forms. ...

It was discovered by J. C. Watson on May 12, 1872, and named after Hermione, daughter of Menelaus and Helen in Greek mythology. James Craig Watson (January 28, 1838 – November 22, 1880) was a Canadian-American astronomer born in the village of Fingal in Ontario, Canada. ... May 12 is the 132nd day of the year in the Gregorian Calendar (133rd in leap years). ... 1872 was a leap year starting on Monday (see link for calendar). ... In Greek mythology, Hermione was a daughter of Menelaus and Helen. ... Menelaus (also transliterated as MenelÃ¡os), in Greek mythology, was a king of Sparta and son of Atreus and Aerope. ... Helen of Troy by Evelyn de Morgan Helen was the wife of Menelaus and reputed to be the most beautiful woman in the world, and her abduction by Paris brought about the Trojan War. ... Greek mythology comprises the collected narratives of Greek gods, goddesses, heroes, and heroines, originally created and spread within an oral-poetic tradition. ...

Hermione is a Cybele asteroid and orbits beyond most of the main belt asteroids. 65 Cybele (sib-a-lee) is one of the largest asteroids in the main belt. ... In physics, an orbit is the path that an object makes, around another object, whilst under the influence of a source of centripetal force, such as gravity. ...

A satellite of Hermione was discovered in 2002 from the Keck II telescope. The satellite measures about 18 km in diameter and orbits at a distance of about 800 km. One revolution around the primary takes 1.63 days to complete. The satellite is currently designated S/2002 (121) 1. It has not yet been officially named, but "LaFayette" has been proposed by a group of astronomers in reference to the frigate used in secret by the Marquis de Lafayette to reach America to help the insurgents. An asteroid moon is an asteroid that orbits another asteroid. ... 2002 is a common year starting on Tuesday of the Gregorian calendar. ... The Mauna Kea Observatory, an institute of the University of Hawaii, is considered one of the most important land-based observatories in the world for its isolated, unobstructed views of space without interference from man-made light sources. ... A kilometre (American spelling: kilometer, symbol: km) is a unit of length equal to 1000 metres (from the Greek words khilia = thousand and metro = count/measure). ... A day is any of several different units of time. ... Marie-Joseph-Paul-Roch-Yves-Gilbert du Motier, marquis de La Fayette (September 6, 1757â€“May 20, 1834), was a French aristocrat most famous for his participation in the American Revolutionary War and early French Revolution. ...

In December 2003, the adaptive optics of the Keck telescope were able to resolve the shape of Hermione. The bi-lobated shape of Hermione is easily perceived from the images. Adaptive optics is a technology to improve the performance of reflecting telescopes by reducing the effects of atmospheric distortion, or twinkling. ...

The satellite discovery made possible an accurate measurement of mass and density of the asteroid. Early results indicate a very porous body, but further studies have cast doubt on this.

Occultations by Hermione have been successfully observed three times so far, the last time in February, 2004. In this July, 1997 still frame captured from video, the bright star Aldebaran has just reappeared on the dark limb of the waning crescent moon in this predawn occultation. ... February is the second month of the year in the Gregorian Calendar. ... 2004 is a leap year starting on Thursday of the Gregorian calendar. ...

External links

120 Lachesis is a very large and very dark main belt asteroid. ... 122 Gerda is a fairly large outer main belt asteroid. ...

Categories: Binary asteroids | Cybele asteroids Minor planets, or planetoids are minor bodies of the solar system orbiting the sun that are larger than meteoroids (the largest of which might be taken to be around 10 meters or so across) but smaller than major planets (Mercury having a diameter of about 4880 km). ... Vulcanoids are hypothetical asteroids that may orbit in a dynamically stable zone between 0. ... The asteroid belt is a region of the solar system falling roughly between the planets Mars and Jupiter where the greatest concentration of asteroid orbits can be found. ... Near-Earth objects (NEO) are asteroids, comets and large meteoroids whose orbit intersects Earths orbit and which may therefore pose a collision danger. ... Image of the Trojan asteroids in front of and behind Jupiter along its orbital path. ... The centaurs are a class of icy planetoids that orbit the Sun between Jupiter and Neptune, named after the mythical race of centaurs. ... A trans-Neptunian object (TNO) is any object in the solar system with all or most of its orbit beyond that of Neptune. ... Damocloids are asteroids such as 5335 Damocles and (16746) 1996 PW that have long-period highly eccentric orbits typical of periodic comets such as 1P/Halley, but without showing a cometary coma or tail. ... Comet Hale-Bopp, showing a white dust tail and blue gas tail (February 1997) A comet is a small body in the solar system that orbits the sun and (at least occasionally) exhibits a coma (or atmosphere) and/or a tail -- both due primarily to the effects of solar radiation... Artists rendering of the Kuiper Belt and more distant Oort cloud. ... This image is an artists rendering of the Oort cloud and the Kuiper Belt. ... An asteroid moon is an asteroid that orbits another asteroid. ... Presentation of the solar system (not to scale). ... This is a list of numbered asteroids, in sequential order. ... This page alphabetically lists the first thousand asteroids to be numbered, which are mostly in the main belt. ...

External links GA_googleFillSlot("encyclopedia_square");

External links