[spyrosk]

Disclaimer: I have a layman's understanding (at best) of astrophysics.

Couldn't this be explained by an orbiting planet colliding with another body and breaking apart? Couldn't this satisfy the number of "comets" required for the hypothesis?

[madaxe_again]

I have a degree in physics... and this seems like as reasonable an explanation as any other to date. We know planets migrate, we know large collisions occur, which tend to be followed by periods of bombardment (e.g. Thea/Earth -> Moon, Jupiter from inner to outer system), so the observations, particularly coupled with the gradual but significant dimming, could correspond with Kessler syndrome on a stellar scale.

Actually, I say that, but they also address this in the paper - a planetary collision would result in a huge amount of excess heat - infrared - and there isn't any. So scratch that. Whatever did this is cold from our point of view.

[kyberias]

I don't get it. Couldn't it have cooled down already and we're only seeing the junk?

[madaxe_again]

Unlikely. The only place for thermal energy to escape is into deep space, in the form of infrared radiation. Given that the dimming has been large and recent, it would have to have been a recent collision - which would take millions of years to cool.

[spyrosk]

I see, very interesting. Thank you for the reply!