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Could also look for young hot WDs in other globular clusters, some closer than the LMC. 47 Tuc is at 4 kpc, for example. Galactic coords are 305, -44.
Much brighter:
There are Chandra xray observations of WDs in 47 Tuc: From Ferraro et al "core of 47 Tuc', 2001:
One advantage of this approach is to use other globular clusters to probe the halo.
what about pulsars? They're only 20 km or so in diameter! That's 2e4 m or 2e6 cm! yup, found a good paper on that....
If diffraction becomes important on Schwarzchild radius rather than Einstein radius scale, what is that? GM/c^2 for M=10^20 gm = 10^17 kg = 6.67E-11*1E17/(3e8)^2 = 7 E-11 m
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