C/1999 U4 (Catalina-Skiff)

C/1999 U4 (Catalina-Skiff) was discovered on October 31st 1999 by Tim Spahr with the Catalina Sky Survey and Brian Skiff from the Lowell Observatory LONEOS project as a magnitude 17.0 object. After discovery observations were found going back to September 18th 1999.

The comet reached perihelion at 4.92AU on October 28th 2001 and is thus a rather distant object, but actually somewhat fainter than average with an absolute visual magnitude of 7.5. The orbit is quite strongly hyperbolic with an excentricity of e=1.008.

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The light curve below shows principally variations due to the varying geocentric distance of the comet and, of course, from "noise" in the measurements. The rate of increase in brightness with heliocentric distance is very slow. The CCD magnitudes were measured in R with a 10" aperture. The CCD total magnitude with a 30" aperture. The comet's rate of brightening with heliocentric distance is very slow.

Observations by:

• Ramón Naves & Montse Campàs - MPC 213
• Rolando Ligustri - MPC 235
• Diego Rodríguez - MPC 458

CCD aperture photometry in apertures of 0'.2 and 0'.5 by:

• Giovanni Sostero
• R. Ligustri
• P. Beltrame
• M. Narduzzi
• M. Zorzenon
• G. Degano
• V. Savani
• L. Guatto

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Última actualización 12/06/2003
Por M.R. Kidger