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.