Orbit of Comet 122P / de Vico

R. L. Branham, Jr.

Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales, C.C. 330, 5500 Mendoza, Argentina (rlb@lanet.com.ar)

Received 2004 August 26
Accepted 2005 January 7

RESUMEN

Se calcula una órbita para el Cometa 122P/ de Vico. La órbita se basa en 400 observaciones en ascensión recta y 396 en declinación hechas entre el 20 de febrero de 1846 y el 16 de mayo de 1996, pero con un intervalo de 150 años entre las observaciones del siglo XIX y las del siglo XX. Fue difícil enlazar la órbita de 1846 con la de 1995 y fue necesario un enfoque de condiciones del contorno para enlazar ambas órbitas en un punto común. El sistema lineal que resulta tiene forma de matriz de banda simétrica y negativa definida, que se resuelve fácilmente con la descomposición de Cholesky libre de raíz cuadrada. Pruebas estadísticas indican que la órbita es buena.

ABSTRACT

An orbit for Comet 122P/ de Vico, based on 400 observations in right ascension and 396 in declination, made between 20 February 1846 and 16 May 1996 but with a gap of 150 years between the 19th and the 20th century observations, is given. Linking to two orbits proved difficult until a boundary value approach was taken: link best fit orbits for the comet to a common fitting point. The linear system to be solved acquires a special form, symmetric, negative-definite, band, that permits efficient solution by square-root free Cholesky decomposition. Statistical tests indicate that the orbit is good.

Key Words: Celestial mechanics — Comets: Individual (Comet 122P/ de Vico) — Methods: Data analysis.

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