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(55636) 2002 TX300
Encyclopedia
is a bright Kuiper belt object in the outer Solar System
estimated to be about 286 km in diameter. It is a large member of the Haumea family
, discovered on October 15, 2002, by the Near-Earth Asteroid Tracking (NEAT) program.
A classical
Kuiper belt
object with the absolute magnitude
between that of 50000 Quaoar
and 20000 Varuna
, has the most eccentric and inclined orbit of the three.
A variability of the visual brightness was also detected which could fit to 7.9 h or 15.8 h rotational period (the distinction between single or double-peaked curved could not be made with confidence). The changes in brightness are quite close to the error margin and could also be due to an irregular shape.
is classified as a classical
Kuiper belt
object and follows an orbit very similar to that of : highly inclined (26°) and moderately eccentric (e ~0.12), far from Neptune’s perturbations (perihelion at ~37 AU). Other mid-sizes cubewanos follow similar orbits as well, notably and .
The diagrams show polar and ecliptic views of the orbits of the two cubewanos. The perihelia (q) and the aphelia (Q) are marked with the dates of passage. The present positions (as of April 2006) are marked with the spheres illustrating relative sizes and differences in albedo
(both objects appear neutral in the visible spectrum).
It has been observed 303 times with precovery
images back to 1954.
In 2004, the non-detection of IR thermal emissions
put an upper limit of 709 km on its diameter and a lower limit on the albedo
of 0.19. In a 2006 International Astronomical Union
press release discussing the IAU 2006 draft proposal, a diagram suggested that TX300 could be as large as 50000 Quaoar
. The artist's diagram was largely based on the concept that TX300 with an absolute magnitude (H) of 3.2 may have an albedo around 0.08, which resulted in a overly optimistic diameter estimate of around 1000 km.
Measurements by the Spitzer Space Telescope
in 2007 showed it may be less than 435 km in diameter. Since this object is a Haumea family
fragment it was assumed to have an albedo of about 0.7 which would result in a diameter of about 360 km.
occulted a relatively bright apparent magnitude
13.1 star in the constellation of Andromeda
on October 9, 2009. This event was visible from Australia, possibly New Zealand, and the southern US and Mexico. The RA
and dec
for this event was about 00 37 13.64 +28 22 23.2.: detailed information for observers was made available. The occultation produced a diameter of 286 kilometers suggesting an albedo of about 0.88. Somewhere between a size of 200 km and 400 km, an icy body becomes rounded by its own gravity. All icy moons with diameters 400 km or more are known to be spherical.
characterized by neutral to blue slope
(1%/1000 Å) with deep (60%) water absorption bands at 1.5 and 2.0 μm).
Mineralogical analysis indicates a substantial fraction of large ice (H2O) particles. The signal-to-noise ratio of the observations was insufficient to differentiate between amorphous or crystalline ice (crystalline ice was reported on Charon, (50000) Quaoar and Haumea).
The proportion of highly processed organic materials (tholin
s), typically present on numerous trans-Neptunian objects, is very low. As suggested by Licandro et al. 2006, this lack of irradiated mantle suggest either a recent collision or comet activity.
Haumea together with similar orbit elements
led to suggestion that is a member of the Haumean collisional family
. The object, together with other members of the family , would be created from ice mantle ejected from the proto-Haumea as result of a collision with another large (~1660 km) body.
Solar System
The Solar System consists of the Sun and the astronomical objects gravitationally bound in orbit around it, all of which formed from the collapse of a giant molecular cloud approximately 4.6 billion years ago. The vast majority of the system's mass is in the Sun...
estimated to be about 286 km in diameter. It is a large member of the Haumea family
Haumea family
The Haumea family is the only identified trans-Neptunian collisional family; that is, the only group of trans-Neptunian objects with similar orbital parameters and spectra that suggest they originated in the disruptive impact of a progenitor body...
, discovered on October 15, 2002, by the Near-Earth Asteroid Tracking (NEAT) program.
A classical
Cubewano
A classical Kuiper belt object, also called a cubewano is a low-eccentricity Kuiper belt object that orbits beyond Neptune and is not controlled by an orbital resonance with Neptune. Cubewanos have orbits with semi-major axes in the 40–50 AU range and, unlike Pluto, do not cross Neptune’s orbit...
Kuiper belt
Kuiper belt
The Kuiper belt , sometimes called the Edgeworth–Kuiper belt, is a region of the Solar System beyond the planets extending from the orbit of Neptune to approximately 50 AU from the Sun. It is similar to the asteroid belt, although it is far larger—20 times as wide and 20 to 200 times as massive...
object with the absolute 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...
between that of 50000 Quaoar
50000 Quaoar
50000 Quaoar is a rocky trans-Neptunian object in the Kuiper belt with one known moon. 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, it is thought by...
and 20000 Varuna
20000 Varuna
20000 Varuna is a large classical Kuiper belt object and a probable dwarf planet. It previously had the provisional designation ' and has been precovered in plates dating back to 1953.-Name:Varuna is named after the Hindu deity,...
, has the most eccentric and inclined orbit of the three.
A variability of the visual brightness was also detected which could fit to 7.9 h or 15.8 h rotational period (the distinction between single or double-peaked curved could not be made with confidence). The changes in brightness are quite close to the error margin and could also be due to an irregular shape.
Orbit
Cubewano
A classical Kuiper belt object, also called a cubewano is a low-eccentricity Kuiper belt object that orbits beyond Neptune and is not controlled by an orbital resonance with Neptune. Cubewanos have orbits with semi-major axes in the 40–50 AU range and, unlike Pluto, do not cross Neptune’s orbit...
Kuiper belt
Kuiper belt
The Kuiper belt , sometimes called the Edgeworth–Kuiper belt, is a region of the Solar System beyond the planets extending from the orbit of Neptune to approximately 50 AU from the Sun. It is similar to the asteroid belt, although it is far larger—20 times as wide and 20 to 200 times as massive...
object and follows an orbit very similar to that of : highly inclined (26°) and moderately eccentric (e ~0.12), far from Neptune’s perturbations (perihelion at ~37 AU). Other mid-sizes cubewanos follow similar orbits as well, notably and .
The diagrams show polar and ecliptic views of the orbits of the two cubewanos. The perihelia (q) and the aphelia (Q) are marked with the dates of passage. The present positions (as of April 2006) are marked with the spheres illustrating relative sizes and differences in 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...
(both objects appear neutral in the visible spectrum).
It has been observed 303 times with precovery
Precovery
Precovery is a term used in astronomy that describes the process of finding the image of an object in old archived images or photographic plates, for the purpose of calculating a more accurate orbit...
images back to 1954.
Size
Emissivity
The emissivity of a material is the relative ability of its surface to emit energy by radiation. It is the ratio of energy radiated by a particular material to energy radiated by a black body at the same temperature...
put an upper limit of 709 km on its diameter and a lower limit on the 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...
of 0.19. In a 2006 International Astronomical Union
International Astronomical Union
The International Astronomical Union IAU is a collection of professional astronomers, at the Ph.D. level and beyond, active in professional research and education in astronomy...
press release discussing the IAU 2006 draft proposal, a diagram suggested that TX300 could be as large as 50000 Quaoar
50000 Quaoar
50000 Quaoar is a rocky trans-Neptunian object in the Kuiper belt with one known moon. 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, it is thought by...
. The artist's diagram was largely based on the concept that TX300 with an absolute magnitude (H) of 3.2 may have an albedo around 0.08, which resulted in a overly optimistic diameter estimate of around 1000 km.
Measurements by the Spitzer Space Telescope
Spitzer Space Telescope
The Spitzer Space Telescope , formerly the Space Infrared Telescope Facility is an infrared space observatory launched in 2003...
in 2007 showed it may be less than 435 km in diameter. Since this object is a Haumea family
Haumea family
The Haumea family is the only identified trans-Neptunian collisional family; that is, the only group of trans-Neptunian objects with similar orbital parameters and spectra that suggest they originated in the disruptive impact of a progenitor body...
fragment it was assumed to have an albedo of about 0.7 which would result in a diameter of about 360 km.
occulted a relatively bright apparent magnitude
Apparent magnitude
The apparent magnitude of a celestial body is a measure of its brightness as seen by an observer on Earth, adjusted to the value it would have in the absence of the atmosphere...
13.1 star in the constellation of Andromeda
Andromeda (constellation)
Andromeda is a constellation in the northern sky. It is named after Andromeda, the princess in the Greek legend of Perseus who was chained to a rock to be eaten by the sea monster Cetus...
on October 9, 2009. This event was visible from Australia, possibly New Zealand, and the southern US and Mexico. The RA
Right ascension
Right ascension is the astronomical term for one of the two coordinates of a point on the celestial sphere when using the equatorial coordinate system. The other coordinate is the declination.-Explanation:...
and dec
Declination
In astronomy, declination is one of the two coordinates of the equatorial coordinate system, the other being either right ascension or hour angle. Declination in astronomy is comparable to geographic latitude, but projected onto the celestial sphere. Declination is measured in degrees north and...
for this event was about 00 37 13.64 +28 22 23.2.: detailed information for observers was made available. The occultation produced a diameter of 286 kilometers suggesting an albedo of about 0.88. Somewhere between a size of 200 km and 400 km, an icy body becomes rounded by its own gravity. All icy moons with diameters 400 km or more are known to be spherical.
Surface
The spectrum in the visible and near-infrared rages is very similar to that of CharonCharon (moon)
Charon is the largest satellite of the dwarf planet Pluto. It was discovered in 1978 at the United States Naval Observatory Flagstaff Station. Following the 2005 discovery of two other natural satellites of Pluto , Charon may also be referred to as Pluto I...
characterized by neutral to blue slope
Spectral slope
In astrophysics and planetary science, spectral slope, also called spectral gradient , is a measure of dependence of the reflectance on the wavelength....
(1%/1000 Å) with deep (60%) water absorption bands at 1.5 and 2.0 μm).
Mineralogical analysis indicates a substantial fraction of large ice (H2O) particles. The signal-to-noise ratio of the observations was insufficient to differentiate between amorphous or crystalline ice (crystalline ice was reported on Charon, (50000) Quaoar and Haumea).
The proportion of highly processed organic materials (tholin
Tholin
Tholin [after the ancient Greek word meaning "not clear"] is a heteropolymer molecule formed by solar ultraviolet irradiation of simple organic compounds such as methane or ethane. Tholins do not form naturally on modern-day Earth, but are found in great abundance on the surface of icy bodies in...
s), typically present on numerous trans-Neptunian objects, is very low. As suggested by Licandro et al. 2006, this lack of irradiated mantle suggest either a recent collision or comet activity.
Origin
Common physical characteristics with the dwarf planetDwarf planet
A dwarf planet, as defined by the International Astronomical Union , is a celestial body orbiting the Sun that is massive enough to be spherical as a result of its own gravity but has not cleared its neighboring region of planetesimals and is not a satellite...
Haumea together with similar orbit elements
led to suggestion that is a member of the Haumean collisional family
Collisional family
In astronomy, a collisional family is a group of objects that are thought to have a common origin in an impact . They have similar compositions, and most share similar orbital elements....
. The object, together with other members of the family , would be created from ice mantle ejected from the proto-Haumea as result of a collision with another large (~1660 km) body.
External links
- AstDys orbital elements
- Orbital simulation from JPL (Java) / Ephemeris