Originally posted by DJW001
reply to post by Theophoros
Both calculations are easy to do for an astrophysicist, but ONLY if the exact angular sizes are available. Since we only have some crappy video
frames to go by, the following mass calculation is only A ROUGH ESTIMATE!
Your entire estimate is based entirely on these "crappy images." In fact, your whole "gravitational microlensing" argument is based on them. The
resolution of the STEREO camera is extremely low. The "size" of the object in the field of vision is a function of the brightness of the point
sources on the CCD receptors; the brighter the object, the larger the number of pixels and, hence, the larger the image. There was no gravitational
lensing effect. As Elenin passes near a background star or planet their brightnesses will be added together by the CCD to create a single "larger,
brighter" image. Your calculation is not merely rough, it is spurious.
edit on 16-9-2011 by DJW001 because: Edit to correct
edit on 16-9-2011 by DJW001 because: (no reason given)
I missed the original post you refer to, but it appears he's trying to calculate mass from a picture in the part you quoted. Mere angular diameter
won't get it done, I don't care how whiz-bang a physicist he is. To work from angular diameter, he has to have distance to get absolute diameter,
and then, on top of that, he has to know the density in order to calculate mass from the volume given by the diameter calculations.
The best physicist on Earth won't get a mass from only a picture, "crappy" or not. There's a world of difference between the density of a comet
and the density of a brown dwarf, "black dwarf", "carbon star", or whatever the claim of the day is for Elelnin. "Spurious" doesn't even begin
to cover it