So the TESS data do not tell us how big the comets were, since the extent of the dust tail
could be very big and not very dense, or less big and more dense.
Some very bright comets may also have an ion tail, oriented at a slight angle to the dust tail
and bluish in colour.
There is a dust tail
and ion tail with ionized particles which comes from the comet itself.
Similar to that of Hale-Bopp, this tail quickly subdivided into a long, narrow plasma tail and a shorter, curved dust tail
. Both would continue to lengthen, and by October 20th they extended 10[degrees] and 4 1/2[degrees], respectively.
When they get too close to the sun, a part of their core gets broken up by the sun's heat, forming a dust tail
. This tail is pushed away from the sun by solar winds and can be millions of miles long.
An examination of the images however indicates the presence of a bright ion tail, but the absence of a bright dust tail
. While the tenuous ion tail shows up well in photographs, it is difficult to see visually and is generally rendered invisible by the light pollution suffered by all three visual observers, who reside nearby to large cities.
A dust tail
extends more than 57,000 miles (92,000 kilometers), far beyond Hubble's field of view.
Visually there were no reports of any tail development until late 2011 August when dust tail
lengths of 0.5[degrees] were seen.
As a comet nears the sun, it typically sports two tails--a brilliant dust tail
and a fainter ion tail.
But some comets, like Hale-Bopp, also have a dust tail
Because this trail of rock and dust reflects lots of sunlight, dust tails
are highly visible.
nuclear diameter: 1-40 km (Halley:16 x 8 x 7 km) nuclear mass: 1014-1019g (Halley: 1017-1018g) nuclear mass loss per apparition: ~1 % coma radius: 104-105 km hydrogen cloud radius: 107 km dust tail
length: 106-107 km dust tail
particle size: 0.1-100 microns dust tail
direction: antisolar, becoming curved as dust particles follow independent orbits ion tail length: 106-108 km ion tail direction: antisolar short-period comets: period < 200 years long-period comets: period > 200 years comet discovery rate: ~12 per year number of comets discovered to date: ~4 000 average number of apparitions per year: ~17
Bailey said: "There's no evidence that the comet has broken up, but in the Soho images, you see the curved dust tail
and rather straighter gas tail.