918 Itha

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918 Itha
000918-asteroid shape model (918) Itha.png
Modelled shape of Itha from its lightcurve
Discovery  [1]
Discovered by K. Reinmuth
Discovery site Heidelberg Obs.
Discovery date22 August 1919
Designations
(918) Itha
Named after
Name picked from the almanac
Lahrer Hinkender Bote   [2] [3]
A919 QD ·1919 FR
A907 CA ·1907 CA
1943 PB
main-belt   [1] [4]  ·(outer)
Itha   [5]
Orbital characteristics   [4]
Epoch 31 May 2020 (JD 2459000.5)
Uncertainty parameter 0
Observation arc 99.72 yr (36,421 d)
Aphelion 3.4078 AU
Perihelion 2.3197 AU
2.8637 AU
Eccentricity 0.1900
4.85 yr (1,770 d)
273.51°
0° 12m 12.24s / day
Inclination 12.070°
330.46°
15.565°
Physical characteristics
Mean diameter
  • 20.44±1.9  km [6]
  • 21.37±0.84 km [7]
  • 21.561±0.106 km [8]
3.47393±0.00006  h [9]
  • 0.203±0.018 [7]
  • 0.2220±0.048 [6]
  • 0.224±0.034 [8]
S (SMASS-I; Xu) [10]
10.6 [1] [4]

    918 Itha (prov. designation: A919 QDor1919 FR) is a stony asteroid and the namesake as well as the principal body of the Itha family, located in the outer region of the asteroid belt. It was discovered by German astronomer Karl Reinmuth at the Heidelberg Observatory on 22 August 1919. [1] The S-type asteroid has a notably short rotation period of only 3.5 hours and measures approximately 21 kilometers (13 miles) in diameter. It was named "Itha", a female name taken from the almanac Lahrer Hinkender Bote , unrelated to the discoverer's contemporaries. [2] [3]

    Contents

    Orbit and classification

    When applying the synthetic hierarchical clustering method (HCM) by Nesvorný, Itha is the principal body and namesake of the Itha family ( 633 ), [5] a small family of stony asteroids with only a few dozen known members. [11] : 23  Other larger and low-numbered members of this family include 968 Petunia, 1067 Lunaria, 3787 Aivazovskij, 4119 Miles and 5232 Jordaens. However, according to another HCM-analysis by Milani and Knežević (AstDys), Itha is a background asteroid as it is not a legitimate family in their analysis. [12] It orbits the Sun in the outer asteroid belt at a distance of 2.3–3.4  AU once every 4 years and 10 months (1,770 days; semi-major axis of 2.86 AU). Its orbit has an eccentricity of 0.19 and an inclination of 12° with respect to the ecliptic. [4] Itha was first observed as A907 CA (1907 CA) at the U.S. Taunton Observatory ( 803 ) in Massachusetts. The body's observation arc begins at Heidelberg Observatory on 23 August 1919, the night after its official discovery observation. [1]

    Naming

    This minor planet was named "Itha", picked from the Lahrer Hinkender Bote , an almanac which was published in Lahr, southern Germany. [2] [3] Especially in the alemannic-speaking region, a Hinkender Bote (lit. "limping messenger") was very popular from the late 17th throughout the early 20th century. The calendar section contains feast days, the dates of important fairs and astronomical ephemerides. For 15 January, the calendar gives "Itha" as the German name day analogue next to Maurus and Habakuk, the protestant and catholic entries in the calendar of saints, likely referring to Saint Maurus and prophet Habakkuk. [13]

    Reinmuth's calendar names

    As with 22 other asteroids – starting with 913 Otila, and ending with 1144 Oda – Reinmuth selected names from this calendar due to his many asteroid discoveries that he had trouble thinking of proper names. These names are not related to the discoverer's contemporaries. Lutz Schmadel, the author of the Dictionary of Minor Planet Names learned about Reinmuth's source of inspiration from private communications with Dutch astronomer Ingrid van Houten-Groeneveld, who worked as a young astronomer at Heidelberg. [2]

    Physical characteristics

    Itha is an S-type asteroid in the SMASS-I classification by Xu (1995). [10] This agrees with the overall spectral type for members of the Itha family. [11] : 23 

    Rotation period

    In June 2011, a rotational lightcurve of Itha was obtained from photometric observations by Julian Oey at Kingsgrove Observatory ( E19 ), Australia, in collaboration with three Argentinian astronomers. Lightcurve analysis gave a well-defined rotation period of 3.47393±0.00006 hours with a brightness variation of 0.30±0.03 magnitude ( U=3 ). [9] Two modeled lightcurves using photometric data from the Lowell Photometric Database and from the BlueEye600 robotic telescope ( L36 ) at Ondřejov Observatory gave a sidereal period of 3.473810±0.000001 and 3.473808±0.000002, respectively. The modelling of the former gave two poles at (59.0°, −59.0°) and (249.0°, −72.0°), while the one of the latter gave only one pole at (72.0°, −54.0°) in ecliptic coordinates (λ, β). [14] [15]

    Diameter and albedo

    According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite, and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), Itha measures (20.44±1.9), (21.37±0.84) and (21.561±0.106) kilometers in diameter, and its surface has an albedo of (0.2220±0.048), (0.203±0.018) and (0.224±0.034), respectively. [6] [7] [8] The Collaborative Asteroid Lightcurve Link derives an albedo of 0.2412 and a diameter of 20.53 km based on an absolute magnitude of 10.6. [16] Other published mean-diameters by the WISE team include (20.335±0.281 km) and (23.715±0.094 km) with corresponding albedos of (0.224±0.034) and (0.1672±0.0333). [16] [10]

    Related Research Articles

    913 Otila is a bright Flora asteroid from the inner regions of the asteroid belt. It was discovered by German astronomer Karl Reinmuth at the Heidelberg Observatory on 19 May 1919. The stony S-type asteroid has a short rotation period of 4.9 hours and measures approximately 12 kilometers in diameter. It was named after a common German female name unrelated to the discoverer's contemporaries, that was taken from the almanac Lahrer Hinkender Bote.

    <span class="mw-page-title-main">920 Rogeria</span>

    920 Rogeria is a dark background asteroid from the central region of the asteroid belt, discovered by German astronomer Karl Reinmuth at the Heidelberg-Königstuhl State Observatory on 1 September 1919. The D-type asteroid (DT) has a rotation period of 12.2 hours and measures approximately 26 kilometers in diameter. It was named "Rogeria", a name unrelated to the discoverer's contemporaries, that was taken from the almanac Lahrer Hinkender Bote.

    921 Jovita is a dark background asteroid, approximately 58 kilometers in diameter, located in the outer regions of the asteroid belt. It was discovered on 4 September 1919, by astronomer Karl Reinmuth at the Heidelberg-Königstuhl State Observatory in southwest Germany. The carbonaceous C-type asteroid (Ch) has a rotation period of 15.6 hours and is likely spherical in shape. It was named "Jovita", a common German female name unrelated to the discoverer's contemporaries, that was taken from the almanac Lahrer Hinkender Bote.

    923 Herluga is a three-body resonant background asteroid, approximately 34 kilometers in diameter, located in the central region of the asteroid belt. It was discovered on 30 September 1919, by astronomer Karl Reinmuth at the Heidelberg Observatory in southwest Germany. The carbonaceous C-type asteroid has a rotation period of 19.7 hours. It was named "Herluga", a common German female name unrelated to the discoverer's contemporaries, that was taken from the almanac Lahrer Hinkender Bote.

    924 Toni is a large background asteroid, approximately 80 kilometers in diameter, from the outer regions of the asteroid belt. It was discovered on 20 October 1919, by German astronomer Karl Reinmuth at the Heidelberg-Königstuhl State Observatory. The X-type asteroid has a rotation period of 19.4 hours. It was named "Toni", a common German female name unrelated to the discoverer's contemporaries, that was taken from the almanac Lahrer Hinkender Bote.

    926 Imhilde is a dark asteroid and the principal body and namesake of the Imhilde family, located in the outer regions of the asteroid belt. It was discovered by astronomer Karl Reinmuth at the Heidelberg Observatory in southwest Germany on 15 February 1920. The carbonaceous C-type asteroid has a rotation period of 26.8 hours and measures approximately 48 kilometers in diameter. It was named "Imhilde", a common German female name unrelated to the discoverer's contemporaries, that was taken from the almanac Lahrer Hinkender Bote.

    <span class="mw-page-title-main">928 Hildrun</span>

    928 Hildrun, is a dark background asteroid, approximately 64 kilometers in diameter, located in the outer region of the asteroid belt. It was discovered on 23 February 1920, by astronomer Karl Reinmuth at the Heidelberg-Königstuhl State Observatory in southwest Germany. The X-type asteroid has a rotation period of 14.1 hours. It was named "Hildrun", a common German female name unrelated to the discoverer's contemporaries, that was taken from the almanac Lahrer Hinkender Bote.

    929 Algunde, is a stony Flora asteroid from the inner regions of the asteroid belt, that measures approximately 11 kilometers in diameter. It was discovered by German astronomer Karl Reinmuth at the Heidelberg-Königstuhl State Observatory on 10 March 1920. The S-type asteroid has a short rotation period of 3.3 hours and is likely spherical in shape. It was named "Algunde", a common German female name unrelated to the discoverer's contemporaries, that was taken from the almanac Lahrer Hinkender Bote.

    <span class="mw-page-title-main">936 Kunigunde</span>

    936 Kunigunde is a dark Themistian asteroid from the outer regions of the asteroid belt, approximately 40 kilometers in diameter. It was discovered on 8 September 1920, by German astronomer Karl Reinmuth at the Heidelberg-Königstuhl State Observatory. The carbonaceous B-type asteroid has a rotation period of 9.4 hours. It was named "Kunigunde", a common German female name unrelated to the discoverer's contemporaries, that was taken from the almanac Lahrer Hinkender Bote.

    938 Chlosinde is a carbonaceous Themistian asteroid, approximately 33 kilometers in diameter, from the outer regions of the asteroid belt. It was discovered by astronomer Karl Reinmuth at the Heidelberg Observatory in southwest Germany on 9 September 1920. The C-type asteroid has an ambiguous rotation period of 13.7 or 19.2 hours. It was named "Chlosinde", a common German female name unrelated to the discoverer's contemporaries, that was taken from the almanac Lahrer Hinkender Bote.

    940 Kordula is a large and dark Cybele asteroid from the outermost region of the asteroid belt, approximately 80 kilometers in diameter. It was discovered on 10 October 1920, by astronomer Karl Reinmuth at the Heidelberg-Königstuhl State Observatory in Germany. The carbonaceous F-type asteroid (FC) has a rotation period of 15.6 hours. It was named "Kordula", a common German female name unrelated to the discoverer's contemporaries, that was taken from the almanac Lahrer Hinkender Bote.

    942 Romilda is a background asteroid, approximately 36 kilometers in diameter, located in the outer region of the asteroid belt. It was discovered by German astronomer Karl Reinmuth at the Heidelberg Observatory on 11 October 1920. The assumed C-type asteroid has a rotation period of 6.97 hours. It was named "Romilda", a common German female name unrelated to the discoverer's contemporaries, that was taken from the almanac Lahrer Hinkender Bote.

    948 Jucunda is a background asteroid, approximately 17 kilometers in diameter, located in the outer region of the asteroid belt. It was discovered on 3 March 1921, by astronomer Karl Reinmuth at the Heidelberg-Königstuhl State Observatory in southwest Germany. The asteroid has a longer-than average rotation period of 26.2 hours. It was named after a common German female name, unrelated to the discoverer's contemporaries, that was taken from the almanac Lahrer Hinkender Bote.

    <span class="mw-page-title-main">968 Petunia</span>

    968 Petunia, is a stony asteroid of the Itha family, approximately 28 kilometers in diameter, located in the outer region of the asteroid belt. It was discovered on 24 November 1921, by astronomer Karl Reinmuth at the Heidelberg Observatory in southern Germany. The bright S-type asteroid has a long rotation period of 61.3 hours. It was named after the genus of flowering plants, Petunia.

    <span class="mw-page-title-main">983 Gunila</span> Main-belt asteroid

    983 Gunila, is a dark background asteroid from the outer regions of the asteroid belt, approximately 74 kilometers in diameter. It was discovered on 30 July 1922, by astronomer Karl Reinmuth at the Heidelberg-Königstuhl State Observatory in Germany. The X-type asteroid has an ambiguous rotation period of 8.3 or 16.6 hours. It was named "Gunila", a common German female name unrelated to the discoverer's contemporaries, that was taken from the almanac Lahrer Hinkender Bote.

    987 Wallia is a large background asteroid from the outer regions of the asteroid belt, approximately 52 kilometers in diameter. It was discovered on 23 October 1922, by astronomer Karl Reinmuth at the Heidelberg Observatory in southern Germany. The D/T-type asteroid has a rotation period of 10.1 hours and shows an unusual trinomial lightcurve. It was named after a common German female name, unrelated to the discoverer's contemporaries, and taken from the almanac Lahrer Hinkender Bote.

    <span class="mw-page-title-main">994 Otthild</span>

    994 Otthild is a stony background asteroid from the central regions of the asteroid belt, approximately 24 kilometers in diameter. It was discovered on 18 March 1923, by astronomer Karl Reinmuth at the Heidelberg-Königstuhl State Observatory. The S-type asteroid has a rotation period of 5.95 hours and is rather regular in shape. It was named after a common German female name, unrelated to the discoverer's contemporaries, and taken from the almanac Lahrer Hinkender Bote.

    <span class="mw-page-title-main">1419 Danzig</span>

    1419 Danzig is a highly elongated Flora asteroid from the inner regions of the asteroid belt. It was discovered on 5 September 1929, by German astronomer Karl Reinmuth at Heidelberg Observatory in southwest Germany. The stony S-type asteroid has a rotation period of 8.1 hours and measures approximately 14 kilometers in diameter. It was named for the city of Gdańsk.

    1174 Marmara, provisional designation 1930 UC, is a stony Eoan asteroid from the outer regions of the asteroid belt, approximately 17 kilometers in diameter. It was discovered on 17 October 1930, by German astronomer Karl Reinmuth at Heidelberg Observatory in southwest Germany. The asteroid was later named after the Sea of Marmara, located between Europe and Asia.

    <span class="mw-page-title-main">1249 Rutherfordia</span> Asteroid

    1249 Rutherfordia, provisional designation 1932 VB, is an elongated, stony Florian asteroid from the inner regions of the asteroid belt, approximately 13 kilometers in diameter. Discovered by Karl Reinmuth at Heidelberg Observatory in 1932, the asteroid was named after Rutherford, New Jersey a suburb of New York City, United States.

    References

    1. 1 2 3 4 5 "918 Itha (A919 QD)". Minor Planet Center. Retrieved 22 February 2020.
    2. 1 2 3 4 Schmadel, Lutz D. (2007). "(918) Itha". Dictionary of Minor Planet Names. Springer Berlin Heidelberg. p. 82. doi:10.1007/978-3-540-29925-7_919. ISBN   978-3-540-00238-3.
    3. 1 2 3 "Lahrer hinkender Bote – Kalender 1925". Badischen Landesbibliothek. 1925. p. 1. Retrieved 21 February 2020. Lahrer Bote archive
    4. 1 2 3 4 "JPL Small-Body Database Browser: 918 Itha (A919 QD)" (2019-05-11 last obs.). Jet Propulsion Laboratory . Retrieved 22 February 2020.
    5. 1 2 "Asteroid 918 Itha – Nesvorny HCM Asteroid Families V3.0". Small Bodies Data Ferret. Retrieved 22 February 2020.
    6. 1 2 3 Tedesco, E. F.; Noah, P. V.; Noah, M.; Price, S. D. (October 2004). "IRAS Minor Planet Survey V6.0". NASA Planetary Data System. 12: IRAS-A-FPA-3-RDR-IMPS-V6.0. Bibcode:2004PDSS...12.....T . Retrieved 22 February 2020.
    7. 1 2 3 Usui, Fumihiko; Kuroda, Daisuke; Müller, Thomas G.; Hasegawa, Sunao; Ishiguro, Masateru; Ootsubo, Takafumi; et al. (October 2011). "Asteroid Catalog Using Akari: AKARI/IRC Mid-Infrared Asteroid Survey". Publications of the Astronomical Society of Japan. 63 (5): 1117–1138. Bibcode:2011PASJ...63.1117U. doi:10.1093/pasj/63.5.1117. (online, AcuA catalog p. 153)
    8. 1 2 3 Masiero, Joseph R.; Grav, T.; Mainzer, A. K.; Nugent, C. R.; Bauer, J. M.; Stevenson, R.; et al. (August 2014). "Main-belt Asteroids with WISE/NEOWISE: Near-infrared Albedos". The Astrophysical Journal. 791 (2): 11. arXiv: 1406.6645 . Bibcode:2014ApJ...791..121M. doi:10.1088/0004-637X/791/2/121.
    9. 1 2 Oey, Julian; Colazo, Carlos; Mazzone, Fernando; Chapman, Andrés (January 2012). "The Lightcurve Analysis of 918 Itha and 2008 Konstitutsiya" (PDF). Minor Planet Bulletin. 39 (1): 1–2. Bibcode:2012MPBu...39....1O. ISSN   1052-8091. Archived from the original (PDF) on 22 February 2020. Retrieved 22 February 2020.
    10. 1 2 3 "Asteroid 918 Itha". Small Bodies Data Ferret. Retrieved 22 February 2020.
    11. 1 2 Nesvorný, D.; Broz, M.; Carruba, V. (December 2014). "Identification and Dynamical Properties of Asteroid Families". Asteroids IV: 297–321. arXiv: 1502.01628 . Bibcode:2015aste.book..297N. doi:10.2458/azu_uapress_9780816532131-ch016.
    12. ↑ "Asteroid 918 Itha – Proper Elements". AstDyS-2, Asteroids – Dynamic Site. Retrieved 22 February 2020.
    13. ↑ "Lahrer hinkender Bote – Kalender 1925". Badischen Landesbibliothek. 1925. p. 2. Retrieved 20 February 2020.
    14. ↑ Ďurech, J.; Hanuš, J.; Oszkiewicz, D.; Vančo, R. (March 2016). "Asteroid models from the Lowell photometric database". Astronomy and Astrophysics. 587: A48. arXiv: 1601.02909 . Bibcode:2016A&A...587A..48D. ISSN   0004-6361.
    15. ↑ Ďurech, Josef; Hanuš, Josef; Brož, Miroslav; Lehký, Martin; Behrend, Raoul; Antonini, Pierre; et al. (April 2018). "Shape models of asteroids based on lightcurve observations with BlueEye600 robotic observatory". Icarus. 304: 101–109. arXiv: 1707.03637 . Bibcode:2018Icar..304..101D. ISSN   0019-1035.
    16. 1 2 "LCDB Data for (918) Itha". Asteroid Lightcurve Database (LCDB). Retrieved 22 February 2020.
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