773 Irmintraud
Encyclopedia
773 Irmintraud is a minor planet
that orbits the Sun
between the planet
s Mars
and Jupiter
. Discovered by German astronomer
Franz Kaiser
at Heidelberg, Germany, on December 22, 1913, the planetoid was named for Irmtraud, an old German woman's name that appears frequently in old songs and sagas
. This D-type asteroid
's previous designation was 1913 TV. The 773 Irmintraud asteroid is a likely source of the Tagish Lake meteorite which landed in Canada on January 18, 2000.
Franz Kaiser
discovered 773 Irmintraud at Heidelberg, Germany.
In 1992, Larry A. Lebofsky and colleagues published an article in which they noted that "unaltered asteroids are thought to represent the raw materials available for terrestrial planet formation and so are important to our understanding of the origin and evolution of the Solar System." Since at least 1980, it was believed that D-type asteroids were unaltered asteroids, ultraprimitive in composition and composed largely of hydrated silicates and organic material. However, in analyzing the spectra of 773 Irmintraud for the water of hydration band (the 3-µm
absorption feature of hydrated silicates), Lebofsky discovered the first D-type asteroid to show the water of hydration band on the surface of the asteroid. Lebofsky concluded that 773 Irmintraud had undergone an alteration process typically seen C-type asteroid
, making 773 Irmintraud and perhaps other D-type asteroids less likely to represent the raw materials available for terrestrial planet formation. In addition, the discovery of water of hydration band on 773 Irmintraud meant that there may be major differences in mineralogy within individual type classification and astronomers must be careful in assuming that the C-, D-, and other type classification relate directly to mineralogy.
In 1997, NASA
added 773 Irmintraud and eventually over one million other names to a microchip placed on board the Stardust spacecraft
that launched February 7, 1999. Placing the names onto the Stardust spacecraft was a public outreach effort. In particular, this served to promote public interest, awareness and support of the space program.
In September 2001, there was speculation that Tagish Lake meteorite which struck in British Columbia
, Canada
on January 18, 2000, was derived from a D-type asteroid
, since the spectral shape and brightness of the meteorite was similar to D-type asteroids. Of the three studied, the 0.032 IRAS
albedo
s (8) of 368 Haidea
and the 0.033 IRAS albedos (8) of 773 Irmintraud are both considered close to the reflectance of the Tagish Lake meteorite. Moreover, even though 368 Haidea was closest spectrally
to the Tagish Lake meteorite, 773 Irmintraud was no more than 0.034 astronomic units
to a chaotic zone associated with one of the Kirkwood gap
s due to the mean motion resonance
with Jupiter
. This made 773 Irmintraud the closest of the three candidates to the associated chaotic zone and thus the most likely of the three as the source of the 2000 Earth impacted meteorite.
The idea that humans held a piece of the asteroid 773 Irmintraud spurred others to act. In 2002, the University of Tokyo
performed near-infrared photometric
and spectroscopic
observations of 773. In addition, the University obtained an accurate lightcurve in Japan through visible photometry
and ultimately found a gap between K- and L- band spectra. From this, the university concluded that results support the idea that Tagish Lake meteorite has a link with D-type asteroids.
On May 22, 2007, at 06:07 UT, Irmintraud occulted
TYC 4908-00263-1, a 10.7 magnitude star in the constellation Sextans
, for observers along a path across New Zealand.
Minor planet
An asteroid group or minor-planet group is a population of minor planets that have a share broadly similar orbits. Members are generally unrelated to each other, unlike in an asteroid family, which often results from the break-up of a single asteroid...
that orbits the Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
between 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,...
s Mars
Mars
Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...
and 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,...
. Discovered by German astronomer
Astronomer
An astronomer is a scientist who studies celestial bodies such as planets, stars and galaxies.Historically, astronomy was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using...
Franz Kaiser
Franz Kaiser
Franz Kaiser was a German astronomer.He worked at the Heidelberg-Königstuhl Observatory from 1911 to 1914 while working on his Ph.D. there, which he obtained in 1915. During this time Heidelberg was a center of asteroid discovery, and Kaiser discovered a number of asteroids during his time...
at Heidelberg, Germany, on December 22, 1913, the planetoid was named for Irmtraud, an old German woman's name that appears frequently in old songs and sagas
Sagàs
Sagàs is a small town and municipality located in Catalonia, in the comarca of Berguedà. It is located in the geographical area of the pre-Pyrenees.-Population:...
. This D-type asteroid
D-type asteroid
D-type asteroids have a very 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 interiors...
's previous designation was 1913 TV. The 773 Irmintraud asteroid is a likely source of the Tagish Lake meteorite which landed in Canada on January 18, 2000.
History
On December 22, 1913, German astronomerAstronomer
An astronomer is a scientist who studies celestial bodies such as planets, stars and galaxies.Historically, astronomy was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using...
Franz Kaiser
Franz Kaiser
Franz Kaiser was a German astronomer.He worked at the Heidelberg-Königstuhl Observatory from 1911 to 1914 while working on his Ph.D. there, which he obtained in 1915. During this time Heidelberg was a center of asteroid discovery, and Kaiser discovered a number of asteroids during his time...
discovered 773 Irmintraud at Heidelberg, Germany.
In 1992, Larry A. Lebofsky and colleagues published an article in which they noted that "unaltered asteroids are thought to represent the raw materials available for terrestrial planet formation and so are important to our understanding of the origin and evolution of the Solar System." Since at least 1980, it was believed that D-type asteroids were unaltered asteroids, ultraprimitive in composition and composed largely of hydrated silicates and organic material. However, in analyzing the spectra of 773 Irmintraud for the water of hydration band (the 3-µm
Micrometre
A micrometer , is by definition 1×10-6 of a meter .In plain English, it means one-millionth of a meter . Its unit symbol in the International System of Units is μm...
absorption feature of hydrated silicates), Lebofsky discovered the first D-type asteroid to show the water of hydration band on the surface of the asteroid. Lebofsky concluded that 773 Irmintraud had undergone an alteration process typically seen C-type asteroid
C-type asteroid
C-type asteroids are carbonaceous asteroids. They are the most common variety, forming around 75% of known asteroids, and an even higher percentage in the outer part of the asteroid belt beyond 2.7 AU, which is dominated by this asteroid type...
, making 773 Irmintraud and perhaps other D-type asteroids less likely to represent the raw materials available for terrestrial planet formation. In addition, the discovery of water of hydration band on 773 Irmintraud meant that there may be major differences in mineralogy within individual type classification and astronomers must be careful in assuming that the C-, D-, and other type classification relate directly to mineralogy.
In 1997, NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
added 773 Irmintraud and eventually over one million other names to a microchip placed on board the Stardust spacecraft
Stardust (spacecraft)
Stardust is a 300-kilogram robotic space probe launched by NASA on February 7, 1999 to study the asteroid 5535 Annefrank and collect samples from the coma of comet Wild 2. The primary mission was completed January 15, 2006, when the sample return capsule returned to Earth...
that launched February 7, 1999. Placing the names onto the Stardust spacecraft was a public outreach effort. In particular, this served to promote public interest, awareness and support of the space program.
British Columbia
British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...
, Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
on January 18, 2000, was derived from a D-type asteroid
D-type asteroid
D-type asteroids have a very 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 interiors...
, since the spectral shape and brightness of the meteorite was similar to D-type asteroids. Of the three studied, the 0.032 IRAS
IRAS
The Infrared Astronomical Satellite was the first-ever space-based observatory to perform a survey of the entire sky at infrared wavelengths....
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...
s (8) of 368 Haidea
368 Haidea
368 Haidea is a large Main belt asteroid. It was discovered by Auguste Charlois on May 19, 1893 in Nice....
and the 0.033 IRAS albedos (8) of 773 Irmintraud are both considered close to the reflectance of the Tagish Lake meteorite. Moreover, even though 368 Haidea was closest spectrally
Spectral signature
Spectral Signatures are the specific combination of reflected and absorbed electromagnetic radiation at varying wavelengths which can uniquely identify an object. The spectral signature of stars indicates the spectrum according to the EM spectrum...
to the Tagish Lake meteorite, 773 Irmintraud was no more than 0.034 astronomic units
Astronomical unit
An astronomical unit is a unit of length equal to about or approximately the mean Earth–Sun distance....
to a chaotic zone associated with one of the Kirkwood gap
Kirkwood gap
A Kirkwood gap is a gap or dip in the distribution of main-belt asteroids with semi-major axis , as seen in the histogram below...
s due to the mean motion 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 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,...
. This made 773 Irmintraud the closest of the three candidates to the associated chaotic zone and thus the most likely of the three as the source of the 2000 Earth impacted meteorite.
The idea that humans held a piece of the asteroid 773 Irmintraud spurred others to act. In 2002, the University of Tokyo
University of Tokyo
, abbreviated as , is a major research university located in Tokyo, Japan. The University has 10 faculties with a total of around 30,000 students, 2,100 of whom are foreign. Its five campuses are in Hongō, Komaba, Kashiwa, Shirokane and Nakano. It is considered to be the most prestigious university...
performed near-infrared photometric
Photometry (astronomy)
Photometry is a technique of astronomy concerned with measuring the flux, or intensity of an astronomical object's electromagnetic radiation...
and spectroscopic
Spectroscopy
Spectroscopy is the study of the interaction between matter and radiated energy. Historically, spectroscopy originated through the study of visible light dispersed according to its wavelength, e.g., by a prism. Later the concept was expanded greatly to comprise any interaction with radiative...
observations of 773. In addition, the University obtained an accurate lightcurve in Japan through visible photometry
Photometry (optics)
Photometry is the science of the measurement of light, in terms of its perceived brightness to the human eye. It is distinct from radiometry, which is the science of measurement of radiant energy in terms of absolute power; rather, in photometry, the radiant power at each wavelength is weighted by...
and ultimately found a gap between K- and L- band spectra. From this, the university concluded that results support the idea that Tagish Lake meteorite has a link with D-type asteroids.
On May 22, 2007, at 06:07 UT, Irmintraud occulted
Occultation
An occultation is an event that occurs when one object is hidden by another object that passes between it and the observer. The word is used in astronomy . It can also refer to any situation wherein an object in the foreground blocks from view an object in the background...
TYC 4908-00263-1, a 10.7 magnitude star in the constellation Sextans
Sextans
Sextans is a minor equatorial constellation which was introduced in 1687 by Johannes Hevelius. Its name is Latin for the astronomical sextant, an instrument that Hevelius made frequent use of in his observations.-Notable features:...
, for observers along a path across New Zealand.