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RE: starship-design: Go Starwisps
L. Parker writes:
> Estimates for distance on GRB's are just that, estimates. Like much else at
> the moment, all we have to go on is parallax and reasoned guesses, which
> is where the distance came from. Granted, it is probably correct, but you
> never know.
Actually, GRBs are believed to be distant because there are some (highly
uncertain) redshift measurements of the assumed optical counterparts.
There are no parallax measurements because no GRBs have been observeed
to repeat, especially not conveniently a year apart. The most accurate
parallax measurements I've heard of are around one milliarcsecond,
allowing distance estimation to approximately 1000 parsecs (3200 light
years), with substantial uncertainty.