The following visibility plots are a guide to the best observing times for C/2013 A1 (Siding Spring) as seen from South America.
Along the (horizontal) x-axis, is the observing date. The left-most (vertical) y-axis shows the time in UT, and the right most y-axis the visual magnitude. The blue line is a plot of the comet's predicted brightness during these dates, and the green marks indicate the best observing time during these dates.
There are different plots for different longitude and latitude points, so you will need to know from which lon/lat you are observing the comet. Click on each image below to view a larger version.
Finally, it is important to note that these files were generated by limiting the UT to when the comet is visible at night, limiting airmass to be less than 3, and assuming the observer is at 0 km altitude for the given latitude/longitude point. Clearly we can't cover every unique circumstance, but these plots should nonetheless be a good guide to help you observe the comet.
NOTE: Observability of this comet from the Northern Hemisphere will limited to the point of being impossible, and thus no equivalent plots for latitudes above +10N have been produced.
Comet Siding Spring visibility from South America (10-deg North, 35-deg West)
Comet Siding Spring visibility from South America (10-deg North, 55-deg West)
Comet Siding Spring visibility from South America (10-deg North, 75-deg West)
Comet Siding Spring visibility from South America (0-deg North, 35-deg West)
Comet Siding Spring visibility from South America (0-deg North, 55-deg West)
Comet Siding Spring visibility from South America (0-deg North, 75-deg West)
Comet Siding Spring visibility from South America (10-deg South, 35-deg West)
Comet Siding Spring visibility from South America (10-deg South, 55-deg West)
Comet Siding Spring visibility from South America (10-deg South, 75-deg West)
Comet Siding Spring visibility from South America (20-deg South, 35-deg West)
Comet Siding Spring visibility from South America (20-deg South, 55-deg West)
Comet Siding Spring visibility from South America (20-deg South, 75-deg West)
Comet Siding Spring visibility from South America (30-deg South, 35-deg West)
Comet Siding Spring visibility from South America (30-deg South, 55-deg West)
Comet Siding Spring visibility from South America 30-deg South, 75-deg West)
Comet Siding Spring visibility from South America (40-deg South,35-deg West)
Comet Siding Spring visibility from South America (40-deg South, 55-deg West)
Comet Siding Spring visibility from South America (40-deg South,75-deg West)
Comet Siding Spring visibility from South America 50-deg South, 35-deg West)
Comet Siding Spring visibility from South America (50-deg South,55-deg West)
Comet Siding Spring visibility from South America (50-deg South, 75-deg West)