OT: Colinearity of Stars in Our Galaxy
- Posted by SDPringle Feb 15, 2014
- 3309 views
As far as the accuracy of tyco-2000. The above quoted 2.5 mili-arc-seconds/year is for the proper motion of a star, it's motion across the sky relative to the fixed background of stars. The positional accuracy is 60 mas. All this is per tyco literature.
What I have found so far, looking at 60min windows, is that 10-30 persent of the stars ar colinear to less thatn 1 arcsec at least for the areas I've looked at. Program blows up if I look at a window larger or there are too may stars in the window. I now have to fugure out why. That's the real problem.
Thanks for all your interest and ideas on how to improve the program. I obviously need to improve the algorithm.
G. Walters,
Somethings that mean seem impossibly unlikely may be actually probable. First thing I would ask is what is the density of stars in the data you are looking at. How many stars are in your 60min by 60min Windows? Perhaps it is just a statistical property of having that many dots in a 3600x3600 grid, generally means that 10-30 % are co-linear. The fact that the galaxy is in a flat shape like a plate makes the stars in space unlike random dots in a grid. You are looking at the plate from its edge, after all.
Play pool, often I cannot find the cue ball, another and a hole are co-linear at the end of the game when there are fewer balls. It is much easier at the beginning of the game. The question here is what is the probability of getting up to 30% of the points colinear in such a grid given this bias of the galaxy is deformed into a plate and our perspective?
S D Pringle
