50000 Quaoar

Sum of 16 Hubble exposures registered on Quaoar.
Discovery[1] and designation
Discovered by	Chad Trujillo, Michael E. Brown
Discovery date	June 4, 2002
Designations
Alternative names[3]	2002 LM60 [2]
Minor planet category	Kuiper belt
Orbital characteristics[4]
Epoch May 18, 2008 (JD 2454600. Early career Trujillo attended Oak Park and River Forest High School in Oak Park Illinois. Education Brown is a Huntsville Alabama native and graduated from Virgil Grissom High School in 1983 Events 781 BC - The first historic Solar eclipse is recorded in China. See also 2002 (disambiguation Year 2002 ( MMII) was a Common year starting on Tuesday of the Gregorian calendar. A provisional designation in astronomy is the naming convention applied to Astronomical objects immediately following their discovery The Kuiper belt (ˈkaɪpɚ to rhyme with "viper" sometimes called the Edgeworth-Kuiper belt, is a region of the Solar System beyond the planets extending In Physics, an orbit is the gravitationally curved path of one object around a point or another body for example the gravitational orbit of a planet around a star In Astronomy, an epoch is a moment in time used as a reference for the Orbital elements of a Celestial body. Events 1152 - Henry II of England marries Eleanor of Aquitaine. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common The Julian date (JD is the interval of time in days and fractions of a day since 4713 B 5)
Aphelion	6. In Celestial mechanics, an apsis, plural apsides (ˈæpsɨdɪːz is the point of greatest or least distance of the Elliptical orbit of an object from 716275 Tm (45. 286 AU)
Perihelion	6. In Celestial mechanics, an apsis, plural apsides (ˈæpsɨdɪːz is the point of greatest or least distance of the Elliptical orbit of an object from 270316 Tm (41. 928 AU)
Semi-major axis	6. In Geometry, the semi-major axis (also semimajor axis) is used to describe the dimensions of ellipses and hyperbolae 493296 Tm (43. TERA is a shielded Twisted pair connector for use with Category 7 twisted-pair data cables developed by The Siemon Company and standardized in 2003 by The metre or meter is a unit of Length. It is the basic unit of Length in the Metric system and in the International 607 AU)
Eccentricity	0. The astronomical unit ( AU or au or au or sometimes ua) is a unit of Length based on the distance from the Earth to the In Astrodynamics, under standard assumptions, any Orbit must be of Conic section shape 0384
Orbital period	105181. The orbital period is the time taken for a given object to make one complete Orbit about another object 6 d (287. A day (symbol d is a unit of Time equivalent to 24 Hours and the duration of a single Rotation of planet Earth with respect to the 97 a)
Average orbital speed	4. In Astronomy, a Julian year (symbol a) is a unit of measurement of Time defined The orbital speed of a body generally a Planet, a Natural satellite, an artificial satellite, or a Multiple star, is the speed at which it 52 km/s
Mean anomaly	284. The second ( SI symbol s) sometimes abbreviated sec, is the name of a unit of Time, and is the International System of Units In the study of orbital dynamics the mean anomaly of an orbiting body is the Angle the body would have traveled about the center of the orbit's Auxiliary circle 861°
Inclination	7. Inclination in general is the Angle between a Reference plane and another plane or axis of direction 988°
Longitude of ascending node	188. This article describes the unit of angle For other meanings see Degree. The longitude of the ascending node (☊ or Ω is one of the Orbital elements used to specify the Orbit of an object in space 893°
Argument of perihelion	148. The argument of periapsis (or argument of perifocus) ( ω) is the Orbital element describing the Angle of an Orbiting body's periapsis 508°
Physical characteristics
Dimensions	1,260 ± 190 km (direct)[5] 844+207−190 km (thermal)[6]
Mass	1. For the majority of numbered Asteroids almost nothing is known apart from a few physical parameters Mass is a fundamental concept in Physics, roughly corresponding to the Intuitive idea of how much Matter there is in an object 0-2. 6×1021 kg
Mean density	2. The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different 0? g/cm³
Equatorial surface gravity	0. A cubic centimetre or cubic centimeter (symbol cm3 —the abbreviation cc, though widely used is deprecated is a commonly used unit of Volume For the majority of numbered Asteroids almost nothing is known apart from a few physical parameters 276-0. 376 m/s²
Equatorial escape velocity	0. In Physics, escape velocity is the speed where the Kinetic energy of an object is equal to the magnitude of its Gravitational potential energy 523-0. 712 km/s
Geometric albedo	0. The geometric albedo of an astronomical body is the ratio of its actual brightness at zero phase angle (i 088 +0. 021−0. 012 [5] 0. 1986 +0. 13−0. 07 [6]
Temperature	~43 K
Spectral type	(moderately red) B-V=0. Temperature is a physical property of a system that underlies the common notions of hot and cold something that is hotter generally has the greater temperature The kelvin (symbol K) is a unit increment of Temperature and is one of the seven SI base units The Kelvin scale is a thermodynamic Asteroids are assigned a type based on spectral shape Color, and sometimes Albedo. 94, V-R=0. 65
Absolute magnitude	2. In Astronomy, absolute magnitude (also known as absolute visual magnitude) is the Apparent magnitude an object would have if it were at a standard 6

50000 Quaoar (pronounced /ˈkwɑːwɑr/ or /ˈkwaʊɚ/ (kwaa'·waar or kwow'·ər), Tongva [qʷɑoɑr], [2]) is a Trans-Neptunian object orbiting the Sun in the Kuiper belt. The Tongva language (also known as the Gabrieliño language) is an Uto-Aztecan language spoken by the Tongva, a Native American people who live A trans-Neptunian object (TNO is any object in the Solar system that Orbits the sun at a greater distance on average than Neptune. The Kuiper belt (ˈkaɪpɚ to rhyme with "viper" sometimes called the Edgeworth-Kuiper belt, is a region of the Solar System beyond the planets extending It was discovered on June 4, 2002 by astronomers Chad Trujillo and Michael Brown at the California Institute of Technology from images acquired at the Samuel Oschin Telescope at Palomar Observatory. Events 781 BC - The first historic Solar eclipse is recorded in China. See also 2002 (disambiguation Year 2002 ( MMII) was a Common year starting on Tuesday of the Gregorian calendar. Early career Trujillo attended Oak Park and River Forest High School in Oak Park Illinois. Education Brown is a Huntsville Alabama native and graduated from Virgil Grissom High School in 1983 The California Institute of Technology (commonly referred to as Caltech) is a private, Coeducational research university located in Pasadena The Samuel Oschin telescope is a 48-inch (122-m aperture Schmidt camera at the Palomar Observatory in northern San Diego County, California Palomar Observatory is a privately owned Observatory located in San Diego County California, 90 miles (145 Km) Southeast of Mount Wilson

Discovery

The discovery of Quaoar, a magnitude 18. The apparent magnitude ( m) of a celestial body is a measure of its Brightness as seen by an observer on Earth, normalized to the value 5 object located in the constellation Ophiuchus, was announced on October 7, 2002, at a meeting of the American Astronomical Society. In common usage a constellation is a group of celestial bodies that are connected together in some arrangement typically stars to form a visible figure or picture Ophiuchus (Ὀφιοῦχος ˌɒfiːˈuːkəs is one of the 88 Constellations and was also one of the 48 listed by Ptolemy. Events 3761 BC - The epoch (origin of the modern Hebrew calendar ( Proleptic Julian calendar) See also 2002 (disambiguation Year 2002 ( MMII) was a Common year starting on Tuesday of the Gregorian calendar. The American Astronomical Society (AAS sometimes pronounced "double-A-S" is a US society of professional astronomers and other interested individuals The earliest prediscovery image proved to be a May 25, 1954 plate from Palomar Observatory. Precovery (prediscovery is a term used in Astronomy that describes the process of finding the Image of an object (usually a Minor planet, but sometimes Events 1085 - Alfonso VI of Castile takes Toledo Spain back from the Moors. Year 1954 ( MCMLIV) was a Common year starting on Friday (link will display full 1954 Gregorian calendar) It may qualify as a dwarf planet, given its size inferred from direct observation by the Hubble Space Telescope. A dwarf planet, as defined by the International Astronomical Union (IAU is a Celestial body Orbiting the Sun that is massive enough to be rounded The Hubble Space Telescope ( HST; also known colloquially as "the Hubble" or just "Hubble" is a space telescope that was carried into

Name

The planetoid's name follows International Astronomical Union rules by naming trans-Neptunian objects after deities associated with creation myths (see planetary nomenclature). A trans-Neptunian object (TNO is any object in the Solar system that Orbits the sun at a greater distance on average than Neptune. See also List of deities A deity is a Postulated Preternatural or Supernatural Being, who is always A creation myth is a supernatural mytho-[[religion religious]] story or explanation that describes the beginnings of humanity, Earth, life, and Planetary nomenclature, like terrestrial nomenclature is a system of uniquely identifying features on the surface of a Planet or Natural satellite so that the features “Quaoar” is the name of a creation deity of the Native American Tongva people, native to the area around Los Angeles, where the discovery was made. Quaoar (pronounced kwaa'·waar or kwow'·ər, English) is the name of a creation deity of the Native American Tongva people native to Native Americans in the United States are the indigenous peoples from the regions of North America now encompassed by the continental United States Tongva may also refer to the Tongva language. The Tongva are a Native American people who inhabited the area in and around Los Angeles Los Angeles (lɑˈsændʒələs los ˈaŋxeles in Spanish) is the largest City in the state of California and the American West The IAU approved the name Quaoar, making it the official name; it also has the provisional designation 2002 LM₆₀. A provisional designation in astronomy is the naming convention applied to Astronomical objects immediately following their discovery The “memorable” number 50000 is a witness to the exciting race to discover a Pluto-sized object; Quaoar’s discovery followed that of 20000 Varuna and was in turn followed by bigger discoveries (see below). This article is about 20000 Varuna, a minor planet For other uses of the word see Varuna (disambiguation 20000 Varuna ( The efforts were finally rewarded with the discovery of an object bigger than Pluto, namely Eris.

Size

Quaoar compared to Eris, Pluto, (136472) 2005 FY₉, (136108) 2003 EL₆₁, Sedna, Orcus, Varuna, and Earth.

Quaoar is estimated to have a diameter of 1,260 ± 190 km^[5], which at the time of discovery in 2002 made it the largest object found in the solar system since the discovery of Pluto. The Solar System consists of the Sun and those celestial objects bound to it by Gravity. Quaoar was later supplanted by Eris, Sedna, 2003 EL₆₁, and 2005 FY₉. TemplateInfobox Planet.--> 90377 Sedna (ˈsɛdnə) is a Trans-Neptunian In addition, it is likely that the subsequently discovered plutino Orcus is also larger than Quaoar. In Astronomy, a plutino is a Trans-Neptunian object in 23 mean motion resonance with Neptune. TemplateInfobox Planet. --> 90482 Orcus (, Orcus originally known by the Provisional designation Quaoar's volume is somewhat more than all of the asteroids put together. Asteroids, sometimes called Minor planets or planetoids', are bodies—primarily of the inner Solar System —that are smaller than planets but It is roughly one tenth the diameter of Earth, one third the diameter of the Moon or half the size of Pluto. EARTH was a short-lived Japanese vocal trio which released 6 singles and 1 album between 2000 and 2001

Quaoar was the first trans-Neptunian object to be measured directly from Hubble Space Telescope (HST) images, using a new, sophisticated method (see Brown’s pages for a non-technical description and his paper^[5] for details). A trans-Neptunian object (TNO is any object in the Solar system that Orbits the sun at a greater distance on average than Neptune. The Hubble Space Telescope ( HST; also known colloquially as "the Hubble" or just "Hubble" is a space telescope that was carried into Given its distance Quaoar is on the limit of the HST resolution (40 milliarcseconds) and its image is consequently "smeared" on a few adjacent pixels. A minute of arc, arcminute, or MOA is a unit of angular measurement, equal to one sixtieth (1/60 of one degree. By comparing carefully this image with the images of stars in the background and using a sophisticated model of HST optics (point spread function (PSF)), Brown and Trujillo were able to find the best fit disk size which would give a similar blurred image. The point spread function ( PSF) describes the response of an imaging system to a Point source or point object This method was recently applied by the same authors to measure the size of Eris.

However, these estimates only marginally agree with the recent (2007) infrared measurements by Spitzer Space Telescope suggesting a much larger albedo (0. Infrared ( IR) radiation is Electromagnetic radiation whose Wavelength is longer than that of Visible light, but shorter than that of The Spitzer Space Telescope (formerly the Space Infrared Telescope Facility, SIRTF) is an Infrared Space observatory. The albedo of an object is the extent to which it diffusely reflects light from the sun 19) and consequently a smaller diameter (844. 4 ^{+206. 7}_{−189. 6} km)^[6].

Orbit

Orbits of Quaoar and Pluto - ecliptic view.

Orbits of Quaoar (blue) and Pluto (red) - polar view.

Quaoar orbits at about 6 billion kilometres (3. 7 billion miles) from the Sun with an orbital period of 287 years. The Sun (Sol is the Star at the center of the Solar System. To help compare Orders of magnitude of different times this page lists times between 109 Seconds (a gigasecond) and 1010 seconds (31

The orbit is near-circular and moderately-inclined (~8°), typical for the population of small classical Kuiper Belt objects (KBO) but exceptional among the large KBO. Inclination in general is the Angle between a Reference plane and another plane or axis of direction In astronomy a classical Kuiper Belt object, also called a cubewano (ˌkjuːbiːˈwɑːnoʊ is a Kuiper belt object that Orbits beyond Neptune The Kuiper belt (ˈkaɪpɚ to rhyme with "viper" sometimes called the Edgeworth-Kuiper belt, is a region of the Solar System beyond the planets extending Varuna, 2003 EL₆₁ and 2005 FY₉ are all on highly inclined, more eccentric orbits. This article is about 20000 Varuna, a minor planet For other uses of the word see Varuna (disambiguation 20000 Varuna ( In Astrodynamics, under standard assumptions, any Orbit must be of Conic section shape

The polar view compares the near-circular Quaoar's orbit to highly eccentric (e=0. 25) orbit of Pluto (Quaoar’s orbit in blue, Pluto’s in red, Neptune in grey). Neptune ( English|AmE] ] is the eighth and farthest Planet from the Sun in the Solar System. The spheres illustrate the current (April 2006) positions, relative sizes and colours. The perihelia (q), aphelia (Q) and the dates of passage are also marked. In Celestial mechanics, an apsis, plural apsides (ˈæpsɨdɪːz is the point of greatest or least distance of the Elliptical orbit of an object from In Celestial mechanics, an apsis, plural apsides (ˈæpsɨdɪːz is the point of greatest or least distance of the Elliptical orbit of an object from

At 43 AU and a near-circular orbit, Quaoar is not significantly perturbed by Neptune, unlike Pluto which is in 2:3 orbital resonance with Neptune. In Celestial mechanics, an orbital resonance occurs when two Orbiting bodies exert a regular periodic gravitational influence on each other usually due to their The ecliptic view illustrates the relative inclinations of the orbits of Quaoar and Pluto. Note that Pluto's aphelion is beyond (and below) Quaoar's orbit, so that Pluto is closer to the Sun than Quaoar at some times of its orbit, and farther at others. The Sun (Sol is the Star at the center of the Solar System.

As of 2008, Quaoar is currently only 13. 9 AU^[7] from Pluto making it the closest large body to the Pluto-Charon system. By Kuiper Belt standards this is very close.

Physical characteristics

Quaoar is believed to be a mixture of rock and ice, like other Kuiper Belt Objects (KBOs); however its very low albedo (estimated at 0. The Kuiper belt (ˈkaɪpɚ to rhyme with "viper" sometimes called the Edgeworth-Kuiper belt, is a region of the Solar System beyond the planets extending The albedo of an object is the extent to which it diffusely reflects light from the sun 1, but still much higher than that of Varuna (0. This article is about 20000 Varuna, a minor planet For other uses of the word see Varuna (disambiguation 20000 Varuna ( 04)) indicates that the ice has disappeared from Quaoar's outer layers. The surface is moderately red, meaning that the object is relatively more reflective in the red and near-infrared than in the blue. 20000 Varuna and 28978 Ixion are also moderately red in the spectral class. This article is about 20000 Varuna, a minor planet For other uses of the word see Varuna (disambiguation 20000 Varuna ( TemplateInfobox Planet. --> 28978 Ixion (ɪkˈsaɪən ik-SYE-ən, sometimes Larger KBOs are often much brighter because they are covered in more ice and have a higher albedo, and thus they present a neutral colour (see colour comparison). A trans-Neptunian object (TNO is any object in the Solar system that Orbits the sun at a greater distance on average than Neptune.

Hubble photo used to measure size of Quaoar.

In 2004, scientists were surprised to find signs of crystalline ice on Quaoar, indicating that the temperature rose to at least −160 °C (110 K or −260 °F) sometime in the last ten million years^[8]. In Materials science, a crystal is a Solid in which the constituent Atoms Molecules or Ions are packed in a regularly ordered repeating Ice is a Solid phase, usually crystalline, of a Non-metalic substance that is liquid or gas at Room temperature, such as Ammonia The Celsius Temperature scale was previously known as the centigrade scale. Fahrenheit is a temperature scale named after Daniel Gabriel Fahrenheit (1686–1736 a German Physicist who proposed it in 1724 Speculation began as to what could have caused Quaoar to heat up from its natural temperature of −220 °C (55 K or −360 °F). Some have theorized that a barrage of mini-meteors may have raised the temperature, but the most discussed theory speculates that cryovolcanism may be occurring, spurred by the decay of radioactive elements within Quaoar's core^[9]. A cryovolcano is literally an Icy Volcano. Cryovolcanoes form on Icy moons and possibly on other low- Temperature Astronomical objects Radioactive decay is the process in which an unstable Atomic nucleus loses energy by emitting ionizing particles and Radiation.

Since then (2006), crystalline water ice was also found on 2003 EL₆₁ but present in larger quantities and thought to be responsible for the very high albedo of that object (0. 7)^[10].

More precise (2007) observations of Quaoar's near infrared spectrum indicate the presence of small (5%) quantity of (solid) methane and ethane^[11]. Infrared spectroscopy (IR spectroscopy is the subset of Spectroscopy that deals with the Infrared region of the Electromagnetic spectrum. Methane is a Chemical compound with the molecular formula. It is the simplest Alkane, and the principal component of Natural gas. ETHANE is a mnemonic indicating a protocol used by Emergency services to report situations which they may be faced with especially as it relates to major incidents where Given its boiling point (112 K), methane is a volatile ice at average Quaoar surface temperatures, unlike water ice or ethane (boiling point 185 K). The boiling point of a liquid is the temperature at which the Vapor pressure of the liquid equals the environmental pressure surrounding the liquid Both models and observations suggest that only a few larger bodies (Pluto, Eris, 2005 FY₉) can retain the volatile ices while the dominant population of small TNOs lost them. Quaoar with only small amounts of methane appears to be in an intermediary category^[11].

If the New Horizons mission visits several Kuiper Belt Objects after visiting Pluto in 2015, our knowledge of the surfaces of small KBOs should improve but encounters with large objects seem unlikely. New Horizons is a Robotic spacecraft mission by NASA currently underway 2015 ( MMXV) will be a Common year starting on Thursday of the Gregorian calendar.

Satellite

The discovery of a satellite of Quaoar was reported in IAUC 8812 on 22 February 2007 [3]. Events 1495 - King Charles VIII of France enters Naples to claim the city's throne Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. The orbit of this satellite has yet to be determined. The satellite was found at 0. 35 arcsec from Quaoar with magnitude difference of 5. A minute of arc, arcminute, or MOA is a unit of angular measurement, equal to one sixtieth (1/60 of one degree. In Astronomy, absolute magnitude (also known as absolute visual magnitude) is the Apparent magnitude an object would have if it were at a standard 6^[12]. Assuming an albedo similar to that of the primary the magnitude suggests the diameter of 100 km. The albedo of an object is the extent to which it diffusely reflects light from the sun

References

External links

• Quaoar discoverers' webpage
• Orbital simulation from JPL (Java) / Ephemeris
• Astronomers Contemplate Icy Volcanoes in Far Places - New York Times article
• Quaoar, the newest planet . . . or is it? - article in an Australian newspaper
• New Planet-Shaped Body Found in Our Solar System - article in National Geographic
• Volcanism possible on planet-like Quaoar - CNN. com
• Chilly Quaoar had a warmer past - Nature. com article