[BAA Comets] Tail rays from 2014Q2

[Richard Miles]

Hi Peter,

Very nice image indeed.

Yes - a good question - why the multiple weak strands or streamers 
comprising the tail of this comet?

Well, Nicolas Biver has just commented on a French comet group that the dust 
tail of this comet is almost non-existent as well as being weak in ions. His 
radio telescope measurements from IRAM five days ago showed lots of 
different molecules but that the comet is very low in CO (~2%). His 
interpretation is that the streamers are largely composed of H2O molecules 
and ions and that this comet is a veritable ball of water ice.

As to the form of the streamers, the fact that there are lots and that they 
persist in time forming long strands suggests that there are multiple 
sources on the nucleus, each of which feeds H2O vapour into a strand. If the 
nucleus were spinning like a typical cometary nucleus, the individual 
strands would have been woven together by its rotation (sometimes this can 
create a 'catherine wheel' effect) such that the tail strands would have 
been braided together. So my conclusion is that the nucleus is a slow 
rotator, say turning every few days.

Can someone analyse the evolution of the strands and come up with a possible 
rotation rate / pole orientation?

The comet reaches perihelion in 12 day's time so there is plenty of time for 
it to undergo further changes.

Keep up the good work,

Richard Miles


----- Original Message ----- 
From: "Peter Carson" <petercarson100 at gmail.com>
To: <comets-disc at britastro.org>
Sent: Saturday, January 17, 2015 8:36 PM
Subject: [BAA Comets] Tail rays from 2014Q2


> Hi All,
> I imaged 2014Q2 last night from here in Essex and captured multiple tail 
> rays. See my image at 
> http://www.astromania.co.uk/2014Q2_20150116_2042_PCarson.jpg
> I'm a simple observer and imager and I think I understand the basics of 
> what forms the ion tail and that fluctuations in the solar wind cause 
> waves and disturbances in the tail structure we see. But what causes so 
> many multiple strands to the ion tail all of which have a slightly 
> different path away from the comet nucleus?
>
> Peter Carson