von Bud Guinn:
I took this of C2004/F4 Bradfield yesterday. C8" ultima 2000 Fastar
on a CGE mount.
This was 20pics@1min acquired and processed in AstroArt3 and PS7.
Camera is the Starlight SXV-H9C.....this is one of my first real
uses of this camera in the Fastar mode.
I processed it, and took such long exposures to bring out the tail
von Bud Guinn:
Took this morning...5.4.04.....this is with my SXV-H9C camera hooked
to my Minolta 55mm 1.4 lens....mounted on my telescope.
This shot was taken in Black in White...because of the binning mode
(no color information)...So, I added the blue background.......and
added the color to the two objects from previously taken
images.....the comet color came from one taken yesterday.
Auf der unteren Aufnahme von Jeamy Lee ist übrigens sehr schön der Gegenschweif zu erkennen, sowie auf dieser Aufnahme von Dennis Persyk:
anti-tail or anomalous tail
When a comet's tail appears to be pointing toward the Sun, this is called an anti-tail or anomalous tail. In reality, the tail only appears to be pointing toward the Sun. To get an anti-tail, the comet must produce large ("heavy") dust particles. If this happens, these particles are left along the comet's orbit instead of being pushed away from the Sun and the comet's orbit by light pressure. Often dusty comets will produce particules of different sizes creating a fan-shaped appearance. The smallest dust will be pushed directly away from the Sun (like the gas tail) and the largest will be left in the comet's orbit. When a comet is close to the Sun, the angle of this fan can be 90 degrees or larger. If the Earth-comet-Sun geometry is correct, the dust in the comet's orbit will appear to point toward the Sun. [Try this...make a right (90 degree) angle with your thumb and index finger. Your index finger is the main tail and your thumb is the dust left in the comet's orbit. Point your finger and thumb directly away from you (keeping the angle 90 degrees). Your finger seems to be going in exactly the opposite direct from the thumb. This is what causes an anti-tail.]