[dhuffman@awod.com]

How do you mean 'larger?'

Normally a photon from the galaxy arrives here so rarely that it isn't detected. The event released enough of a flood of photons that many were detected. That the photons were of particularly high energy allows us to determine what is going on.

In the usual meaning of 'larger,' the galaxy is on the order of a hundred LY across and the star, at its normal density, a small fraction of a LY.

[carumba]

How do you mean 'larger?
The order of magnitude of a galaxy size would be greater than a super nova. The crab nebula was a super nova in our galaxy and it wasn't bigger than the milky way. Lets see, Andromeda is dim but visible and it is 200 million LY distant so I thought that twice the distance would be more visible than light blue galaxies. I guess the emission of photons from the nova makes 'seeing' the galaxy like seeing a cop behind a flashlight.