Starship Asterisk*

Is it just a coincidence that the artefact line passing roughly East-West through the the various bright sources in the photograph is in the same orientation as the southern edge of the eastern 'cone' and the northern edge of the western 'cone'? Also, the distance from the center of the 'star' to th...

Many thanks for the links Noel, I am ploughing my way through http://xxx.lanl.gov/abs/astro-ph/9912508 on Weak Gravitational Lensing which seems to be how multiple images are formed rather than rings and arcs. It seems that Einstein's Cross is getting a great deal of telescope time so maybe I can re...

Hi Noel, On the lens issue, (leaving aside that the physics is totally different as far as I have read), a glass medium analog of a simple gravitational lens would be a lens that was flat furthest from the center that increased in curvature towards the center until it reached a peak at the center (a...

I keep coming back to the fact that a gravitational lens does not act like any optical lens or lens system, and that using the term lens only serves to confuse any debate. An optical lens system can produce multiple images because, in the simplest case of a fractured lens where each fragment has a s...

Hi Noel, Thanks for the quick response. My thinking was this; If a quasar is considered a point source by virtue of its distance from the lens, and if the gravitational lens is 'simple', and if the observer, lens, and quasar are aligned, then there is only a single 'null geodesic' lightpath that con...

If anyone is watching this post I would be grateful for a little help with this image and others that show no evidence of Einstein's Rings, but are still attributed to gravitational lensing. To digress. A conventional lens (i.e. an imaging lense) differs from a gravitational lens in one very importa...