ALBUFEIRA

ISON – 21.11.2013 – Whitmer G

(before perihelion)

My Current Assessment of Comet ISON's Status:

(Bruce Gary)

Based on the evidence currently available, I believe that a few hours prior to perihelion the gravitational gradients produced by the sun, combined with the heat that sublimated ice (which is like a glue that was holding the particles together), led to the nucleus breaking up, producing a field of particles and clumps of particles moving apart. With this breakup there was a sudden increase in total surface area for the same mass, and being this close to the sun these particles were quickly heated and produced a burst of outgassing; this could explain the brightening prior to perihelion encounter. After perihelion there was no evidence of a nucleus-based coma, which is consistent with the breakup and outgassing that occurred hours earlier. Instead, there was the appearance of a cloud of particles that was undergoing dispersion due to both the solar wind and light pressure. The solar wind would capture particles, molecules and atoms that were ionized, and carry them away at high speed; the neutral particles would be pushed away from the sun by sunlight pressure. The fading that was seen after perihelion is consistent with this scenario, and suggests that ever since then the material that constituted the comet before perihelion simply continued to disperse and become so spread out that no imaging can be counted upon to capture what's left of the comet. In addition, there may be no more outgassing (for producing a coma and tail) because of the high temperatures that all particles and clumps of particles experienced at perihelion.

In other words, I think Comet ISON is dead!

 
That's my opinion. But keep in mind that I'm no comet expert!

(brucegary.net)