Comet Holmes - a Media Non-event

[davesmith_au]

'08 Mar 29 ~ Guest contribution - S. Wall

On October 24, 2007, Comet 17PHolmes brightened dramatically by a factor of a million. Within 24 hours, it had gone from a small 17th magnitude comet to a magnitude of 2.5, easily visible with the naked eye. It wasn't finished its impressive display just yet though. Holmes kept expanding until by mid-November it had become the largest object in the solar system and had surpassed the Sun in volume. The diameter of the coma had grown from 28 thousand kilometres to 7 million km. ... [more...]

[MGmirkin]

The sun had been electrically active in the days before the "explosion". Upon investigation of data from the ACE satellite, see this movie or this graph, Michael Mozina noticed that there was a large spike in the density of the solar wind on October 22 at 19:45, two days before the infamous flareup. This spike likely switched the comet into normal glow mode and allowed it to grow. Once in normal glow mode, the plasma coma does not require a sustained voltage to maintain that mode.

I assume that the implication of the last sentence was that plasma / electrical effects are non-linear. Such that, once glow mode was initiated (by a large solar wind event?) that a much lower current would be required in order to maintain the glow mode. As opposed to "no current?"

Somehow the last sentence implied, I think, that no further input would be required to maintain glow mode? IE, it would be somehow self-sustaining? But I assume that wasn't the intended implication? Rather that after the large event triggered the outburst, the non-linearity means that a much smaller input was required to sustain the outburst...?

Just wondering,
~Michael Gmirkin

[JoeTB]

The sun had been electrically active in the days before the "explosion". Upon investigation of data from the ACE satellite, see this movie or this graph, Michael Mozina noticed that there was a large spike in the density of the solar wind on October 22 at 19:45, two days before the infamous flareup. This spike likely switched the comet into normal glow mode and allowed it to grow. Once in normal glow mode, the plasma coma does not require a sustained voltage to maintain that mode.

I assume that the implication of the last sentence was that plasma / electrical effects are non-linear. Such that, once glow mode was initiated (by a large solar wind event?) that a much lower current would be required in order to maintain the glow mode. As opposed to "no current?"

Somehow the last sentence implied, I think, that no further input would be required to maintain glow mode? IE, it would be somehow self-sustaining? But I assume that wasn't the intended implication? Rather that after the large event triggered the outburst, the non-linearity means that a much smaller input was required to sustain the outburst...?

Just wondering,
~Michael Gmirkin

Does it work the same way for the sun?

[MGmirkin]

A pertinent question... I would assume so, but perhaps we could get that clarified...

~Michael Gmirkin