@@Martin
Thanks for clarifying what's new here.
Should've acknowledged in my first post really ... observable asymmetric broadening needs pretty extreme conditions, so seeing it elsewhere than a black hole is really very interesting.
3 publicly visible posts • joined 2 May 2007
By Arthur Eddington, during a solar eclipse, in May 1919. He observed bending of starlight around our very own Sun (not a black hole!) which was twice what classical theory would have predicted, and was in fact what Einstein's theory, then only 4 years old, suggested.
For several decades this was the _only_ experimental demonstration of general relativity (GR), a theory which had taken Einstein and a handful of collaborators 10 years to construct since his landmark 1905 papers on special relativity (SR) had left open the rather obvious question, "what happens if this relative motion of which you speak is non-uniform?".
For an inkling of just how monumental this was, compare GR with software development. A five-person team works for 10 years coding a program which, by today's standards, is only moderate in size, but is extremely complex. They have no automated development tools, no system to run the code on, and no test cases - only peer reviews. 4 years later they identify a system and run a single test case - successfully. Several decades later, other test cases run on other systems, all successfully. The original GR program has accumulated plug-ins and applications in the 92 years since v1.0, but virtually no bugfixes. Quite amazing.