Sloan-r' Photometry of Comet 17P/Holmes Beyond 3.8 AU: An Observing Methodology for Short-period Comets Far from Perihelion

Other

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Scientific paper

A photometric method is described for accurately quantifying the brightness of short-period comets far from perihelion. The method utilizes the Sloan Digital Sky Survey Catalog (Data Release 7) as a homogeneous source of reference star magnitudes. Results are based on SDSS-r' filtered images taken using 2.0-m aperture telescopes for which the exposure time was adjusted to achieve a constant motion-blur of 2.0 pixels (0.56 arcsec) on the CCD chip. Aperture photometry using circular and tilted elliptical apertures was performed on images, which were stacked to increase signal to noise. Magnitude dependence on 'seeing' was determined, and this calibration was used to normalize photometry to constant seeing thereby maximizing photometric accuracy. From observations of Comet 17P/Holmes between 2008 October and 2009 March, a very significant outburst of 17P was found to have occurred on 2009 Jan 4.7 (±0.5 day). Night-to-night measurements of the brightness of the inner coma (3000-km radius) exhibited a scatter of only 0.015-0.019 mag. No short time-scale (<36 hr) periodicity was found in the fading lightcurve. From literature data, it was estimated that reflected light from the nucleus contributed 7-11% of the signal within the inner coma and it is concluded that either the nucleus of 17P must be relatively spherical (projected axial ratio of <1.25), or, if its shape is more typical of other comet nuclei, it has a rotational period in excess of 10 days (assuming the observations were not made with the nucleus 'pole-on' to the Earth). Evidence from intermittent activity displayed by the nucleus is indicative of a possible 44 day rotation period.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Sloan-r' Photometry of Comet 17P/Holmes Beyond 3.8 AU: An Observing Methodology for Short-period Comets Far from Perihelion does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Sloan-r' Photometry of Comet 17P/Holmes Beyond 3.8 AU: An Observing Methodology for Short-period Comets Far from Perihelion, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Sloan-r' Photometry of Comet 17P/Holmes Beyond 3.8 AU: An Observing Methodology for Short-period Comets Far from Perihelion will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1111700

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.