Comet Hartley 103P Periodic comet in Cassiopeia on 10/3/10

Uploaded 10/8/10

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 This comet is rapidly accelerating across the fall sky to a mid October closest approach to the Earth. For this image, the comet was still at 7.5th magnitude, and only dimly visible in a pair of 11x80 binoculars. Photographically things are much better, this comet has an emerald color with a short fan tail inside a growing coma. The field in the above images, presented with the same data two ways is 2 degrees wide.

The comet was processed primarily in Images Plus. This program allows me to process comet images such that either the comet, stars or both are aligned in the final image. The comets rapid motion across the sky is illustrated by the top image, processed with the nucleus in register to track the comet. The software does this automatically. The rich Milky Way star field can be seen with plenty of star colors brought out by the trailing process.

The lower image was processed with the same data, and has both stars and comet in register at the same time. This frame corresponds to the position of the comet in the first image. Creating it was easy, the comet and stars were combined separately in register using median. This then was automatically aligned and merged with the first image in the set to produce a stationary comet against a non trailing star field.

Lens: 8" f/4 Newtonian Astrograph Platform: Astrophysics AP1200 Exposure: 90x 2m = 3 h Location: Payson, Arizona Elevation: 5150 ft. Sky: Seeing 6/10, Transparency 6/10 Outside Temperature: 60F Processing Tools: Photoshop CS2 HOME GALAXIES EMISSION NEBS REFLECTION NEBS COMETS GLOBULARS OPEN CLUST PLANETARIES LINKS