Richard L. Branham, Jr.
IANIGLA, C.C. 330, 5500 Mendoza, Argentina. (rbranham@lab.cricyt.edu.ar).
Received 2015 June 16.
Accepted 2015 August 7.
]]> RESUMEN
Con el objeto de mejorar la órbita de Oppolzer de 1864, se calcula una nueva órbita para el Cometa C/1861 G1 (Thatcher), el cual está asociado a la lluvia de estrellas de las Líridas. La nueva órbita se basa en 649 observaciones hechas entre el 11 de abril y el 7 de septiembre de 1861, 326 en ascensión recta y 323 en declinación. La órbita final utiliza los residuos calculados con la función de ponderación de Welsch. El período del cometa, 416 ± 0.56 años, concuerda con el de Oppolzer, 415 años, pero otros elementos orbitales, como la inclinación, discrepan. Si bien los residuos post-perihelio se presentan relativamente al azar, con una probabilidad del 52.1% de serlo, los residuos pre-perihelio no son azarosos, lo cual indica posibles desviaciones del movimiento kepleriano debidas a la expulsión de material meteorítico. El Cometa Thatcher no está relacionado con el Gran Cometa de 1861.
ABSTRACT
A new orbit is calculated for Comet C/1861 G1 (Thatcher), associated with the Lyrid meteor shower, to replace Oppolzer's orbit of 1864. The new orbit is based upon 649 observations, 326 in right ascension and 323 in declination, made between 11 April 1861 and 7 Sept. 1861. The final orbit uses residuals calculated with the Welsch weighting function. The comet's period of 416.87 ± 0.56 yr agrees with Oppolzer's period of 415 yr athough other elements such as the inclination differ. Although the post-perihelion residuals are relatively random, 52.1% probability of randomness, pre-perihelion residuals lack randomness indicating possible deviations from Keplerian motion caused by ejection of meteoritic material. Comet Thatcher is unrelated to the Great comet of 1861.
Key Words: celestial mechanics — comets: individual — methods: data analysis.
DESCARGAR ARTÍCULO EN FORMATO PDF
REFERENCES
]]>Arter, T.R., and Williams, I.P. 1997, MNRAS 289, 721 [ Links ]
Branham, R.L. Jr. 1990, Scientific Data Analysis (New York, Springer) [ Links ]
Branham, R.L. Jr. 2005, Plan. & Space Sci. 53, 1437 [ Links ]
Branham, R.L. Jr. 2011, Processing 19th century cometary observations, in: Melark, P.G. (ed.), Comets: Characteristics, Composition and Orbits, Nova, New York, 123 [ Links ]
Branham, R.L. Jr. 2012, AN 333, 118 [ Links ]
Branham, R.L. Jr. 2014, Rev. Mex. A & A 50, 109 [ Links ]
Knuth, D.E.: 1981, The Art of Computer Programming, Vol. 2, 2nd ed. (Addison-Wesley: Reading, Mass. [ Links ])
Królikowska, M., and Dybczynski, P.A. 2010, MNRAS 404, 1886 [ Links ]
Marsden, B.G., Williams, G.V.: 2003, Catalog of Cometary Orbits 2003, Smithsonian Astrophysical Obs., Cambridge, Mass. [ Links ]
Oppolzer, T. 1864, AN 62, 177 [ Links ]
Rice, H.L. 1902 AJ 22, 149 [ Links ]
Scott, F.P. 1964, AJ 69, 372 [ Links ]
Stigler, M.: 1977. Annal. Stat. 5, 1055 [ Links ]
Weiss, E. 1867, AN 63, 382 [ Links ] ]]>