773 Irmintraud

Infobox Planet
width = 25em
name = 773 Irmintraud
background = #FFFFC0
discoverer = Franz Kaiser
discovered = December 22, 1913
discovery_site = Heidelberg
mp_name = Irmintraud
mp_category = Asteroid
alt_names = 1913 TV
orbit_ref =
epoch = August 18, 2005 (JDCT 2453600.5)
aphelion = 3.090 AU
perihelion = 2.625 AU
semimajor = 2.858 AU
eccentricity = 0.081
period = 4.831 a
avg_speed =
inclination = 16.679°
asc_node = 322.477°
mean_anomaly = 121.470°
arg_peri = 334.332°
satellites =
dimensions =
mass =
density =
surface_grav =
escape_velocity =
sidereal_day =
axial_tilt =
pole_ecliptic_lat =
pole_ecliptic_lon =
albedo =
temp_name1 =
mean_temp_1 =
max_temp_1 =
temp_name2 =
max_temp_2 =
spectral_type =
abs_magnitude =

773 Irmintraud is a minor planet that travels between the planets Mars and Jupiter to orbit the Sun with a prograde motion. [NASA (12 Jun 2008) " [http://starbrite.jpl.nasa.gov/pds/viewTargetProfile.jsp?TARGET_NAME=773%20IRMINTRAUD Plantary Data System.] " Accessed June 12, 2008.] 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.Schmadel, Lutz D. (2003) " [http://books.google.com/books?id=KWrB1jPCa8AC&pg=RA1-PA73&dq=773+Irmintraud&sig=0MNn_uQT9u_Nypgokb4EMjqHjeU Dictionary of Minor Planet Names.] " Page 73. Publisher: Springer. ISBN 3540002383] This D-type asteroid was the 773rd minor planet discovered after the January 1, 1801 citing of 1 Ceres and its previous designation was 1913 TV. [Warner, Brian D. (2006) The Minor Planet Observer and the Palmer Divide Observatory " [http://www.minorplanetobserver.com/pdolc/773_Irmintraud.htm 773 Irmintraud] .] The 773 Irmintraud asteroid is a likely source of the Tagish Lake meteorite that impacted Canada on January 18, 2000.Hiroi, Takahiro, et al. (September 21, 2001) Science " [http://www.sciencemag.org/cgi/content/abstract/293/5538/2234 The Tagish Lake Meteorite: A Possible Sample from a D-Type Asteroid.] " Volume 293; Issue 5538; Page 2234.]

History

On December 22, 1913, German astronomer 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."Lebofsky, Larry A. (1992) NASA Technical Reports Server. " [http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19920001612_1992001612.pdf An Infrared Reflectance Study of Low Albedo Surface Constituents.] " N92-10830.] 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 onboard the Stardust spacecraft that launched February 7, 1999.NASA (July 16, 2001) " [http://stardust.jpl.nasa.gov/overview/microchip/names2i2.html Microchip Names (I).] " Accessed June 12, 2008.] 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 that impacted 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 albedos (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 Gaps 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.Ai, Kanno. (2002) Astronomical Herald " [http://sciencelinks.jp/j-east/article/200221/000020022102A0834926.php Photometric and Near-IR Spectroscopic observations of a D-type asteroid, (773) Irmintraud, by SUBARU/IRCS.] " VOL.95; NO.11; PAGE.507-514. Accession number: 02A0834926; Japanese language Journal Code: F0543A; ISSN 0374-2466] 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 06:07 UT, Irmintraud occulted TYC 4908-00263-1, a 10.7 mag star in the constellation Sextans, for observers along a path across New Zealand. [Preston, Steve. (May 19, 2007) asteroidoccultation.com " [http://www.asteroidoccultation.com/2007_05/0522_773_8584.htm (773) Irmintraud / TYC 4908-00263-1 event on 2007 May 22, 06:07 UT] " Accessed June 11, 2008.]

References

External links

* [http://cfa-www.harvard.edu/iau/lists/NumberedMPs.txt Discovery Circumstances: Numbered Minor Planets]
* [http://pdsproto.jpl.nasa.gov/catalog/target/Results.CFM?resultsselbox=773%20IRMINTRAUD NASA Target Catalog Information]