Comet special installment 1. Comet P/Holmes
In the fall of 2007 an unexpected bright comet appeared in the northern sky. It experienced a sudden mass loss event. In about 42 hours it went from a visual magnitude of 17 (out of reach of any instrument less than twenty or so inches in aperture) to 2.8, within easy sight of the unaided eye. I watched it with binoculars from a decently dark site. The comet stayed bright and slowly expanded until it was visually larger than the full moon, and physically larger than the sun. It was round with almost none of a comet's usual directionality, as the emitted matter expanded in an apparent sphere. The comet was near opposition (distance opposite the sun from us), so some of that was a consequence of our seeing it head-on.
How it looked through binoculars
With NGC 1499, the diffuse "California Nebula"
A montage of the changing angular size and surface brightness of the comet over about a month
Long-exposure showed the ion tail and the big green dust halo
In this image the two zones are visible, dust around gas
which reminds me of a nuke blast in orbital space ...
