Homework Help: Stars and the Galaxies

Posted by Sara on Thursday, March 4, 2010 at 7:32pm.

if alpha centauri were to all of a sudden disappear, we wouldn't knknow 4 another 4.3 years. How come? Why would this be the case?

would this be the case because its really far away from us and it's 4.3 light years away. So if it suddenly just vanished out of sight, then it would definetly take 4.3 light years to get back, because that's how long it would take its light to travel.

please correct me if I'm wrong, and list any other info, thanks - by more info, i mean info that you know from the top of ur head, please no links, thanks

Stars and the Galaxies - drwls, Thursday, March 4, 2010 at 8:14pm
Your explanation is correct.

The 4.3 light year distance of Alpha Centauri means that the light we are seeing now was emitted 4.3 years ago. If the star ceased to exist NOW (which is not at all likely to happen), we would not know about it for 4.3 years, because light emitted before is still on the way here.
Stars and the Galaxies - Sara, Thursday, March 4, 2010 at 8:20pm
thanks drwls, :-)

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