Can you identify a star's 'signature' from its spectroscopy? I overheard a discussion between friends:


  If your spaceship was transported to a random location in our galaxy, you could identify nearby stars by their signature, and then triangulate your position. 


Another friend replied. 


  The signature of a star isn't sufficiently unique. You can't identify a star by spectroscopy. 


A third friend chimed in


  There would be enough unique pulsars to work out your position from. 


I came away not convinced on the stellar spectroscopy question. 

My question is: Can you identify a star's 'signature' from its spectroscopy?
Realistically, no - there are too many stars with the same spectrum.

The pulsar idea is a good one, though. There is a reason our location relative to some bright pulsars was sent out on the Voyager plaques: we are confident that a civilisation finding one could then find our sun, and us, as the pulsar rates are unique enough.