Sunday, 22 December 2013

20131221 - ISON Not Found + the start of a theory

Over the past few days two famous telescopes have been looking for C/2012 S1 ISON.

The Arecibo (the world's largest Radio Telescope in Puerto Rico) reported yesterday that they had found nothing. 

The Hubble Telescope reported late yesterday that they had found no trace of it. Here is a link to their results.

There may be a few bits around, but they would be less than 150 meters in size.

So there is no need to throw any life rafts, Just wreaths :( 

Why and when ISON started to break up is now the question that is being asked and various theories, which need to be tested, are being put forward. My personal theory - unproven - is that sometime in the lead up to the 13th November (perhaps a day or two before) the nucleus of the comet started to become unstable, whether a chunk broke away or it started to crack I do not know. The visible effect is shown in this image that SON@OSC took on the morning of the 13th November. If you look a third of the way along the lower tail you can see a discontinuation. +Padma Yanamandra-Fisher  picked up on this event as soon as she saw the image.

Over the next few days the comet physically changes as can be seen in the following image from the morning of the 15th .

The following day, the 16th, it seems calm down a bit (through cloud).

Morning of the 19th through thin cloud again!

The next event was noticed on the morning of the 22nd. +Charles Bell  pointed this out to me. towards the end of the displayed lower tail there is a branch off - looks like half a feather on an arrow. I think that a day or two before there was another major fracture to the nucleus.

This was the last time I saw ISON . I think by this time the nucleus was fatally flawed and came apart during its near encounter with our Sun.

It is important to recognise that the images of ISON represent only part of the history of the comet. They are, of course, an important resource, especially if and when other images can be added to the time line. I still have a number of images to process and perhaps some of those will add to the story.

Other data now needs to be brought together and analysed. A lot, but not all, of this data has either been captured by amateurs or is in the public domain. A number of amateurs have already started modelling this data, some of which at first glance supports my idea. Until I fully understand this data (and other data), myself I will not present it and only then with permission.

I will be looking to see what the professionals come up with. One thing about of astronomy is that there is always something new to learn.


After a cloudy night, this morning I managed to finds some holes in the clouds and brought the cameras into focus and at dawn take some flats.

Late afternoon we struggled up the observatory hill with the framework for the new roll off observatory to house the new telescope.

This evening is cloudy again :( which was disappointing as Search Light Observatory Network had received a request to record a stellar occultation which would been taking place now. Alas the observatory hill is covered with a damp cloud.