Lensing Effect for Stars Near Sagittarius A*

Jim, first of all, it is not my figure, but I am just referring to it as an illustration.
And of course this is not a real-time movie, but one based on the positions over a period of more than 10 years (as you can see from the year numbers in the top left hand corner).

Thomas

Thomas, Also there is a yardstick of 10 light days that is supposed to give the scale of the orbits. So, why not take all of it to be nothing more than a cartoon based on the imagination of the artist? Where's the data indicating any observation is involved? If there are pictures of SagA why not publish them?

Jim, The second reference I gave above in my opening post mentions some relevant publications.
See also www.mpe.mpg.de/www-ir/GC/ from which the image on Dr, Dowdye's website was taken.

Thomas

Thomas, You were making a point about lensing effects and it seems I upset the apple cart here-I'm sorry and it was unintended. It isn't important to your point which is different than I was thinking at the time.

Just an update and correction on this:

I did recently a more thorough derivation of the gravitational lensing effect for objects close to the lensing mass, and it turned out that my estimate above is actually incorrect: the value I gave holds strictly speaking only if the if the lensed star is far behind the lensing mass (as compared to our distance from the latter). If it is much closer on the other hand, it has to be multiplied by a factor r/d where r is the distance of the lensed star from the galactic center and d our distance from the latter (this is straightforward to show by using the cosine and sine laws for the corresponding triangle).

With this, the lensing effect on the stars surrounding the galactic center mass becomes obviously much too small to be observable, but it still leaves the possibility that the lensing (or its absence) could be observed for stars a suitable distance behind the galactic center (i.e. far enough to get a large enough lensing effect, and close enough to have sufficiently short orbital periods so that the effect can be observed within a reasonable time period (e.g. a few years)).

Thomas

Hi Thomas, we were just talking about the star S2 which gets into about 180 a.u. of the super massive object. What are your thoughts on it? It's fifteen solar masses, so it can't be very old. It must be distorted by its close approach, why doesn't it explode?

Also, what do you make of the idea of a neutrino ball?

(Edited)A sudden thought, I simply cannot resist using the splendid barbarism, "periblackholeion"