Time travel on movies and tv always say they were able to tell the year by looking at the stars. But how?
For example Voyager goes back in 1996 and Ensign Kim says astrometrics puts them in the year 1996. In the movie Timeline they said they sent probes and pointed it's cameras at the night sky and determined the date.
http://www.chakoteya.net/voyager/304.htm
Star Trek Voyager
JANEWAY: The question isn't where we are, it's when we are. Mister Kim.
KIM: According to astrometric readings the year is 1996
http://www.script-o-rama.com/movie_scripts/t/timeline-script-transcript-michael-crichton.html
Timeline movie
That's when Mr. Doniger made the brilliant decision to point the camera straight up. So once we cross-referenced star charts to the horizon, we realized that the camera was not only in the wrong place,- but it was in the wrong time.
My problem is my accidental time travelers are amateur astronomers/stargazers (they also have Stellarium software or equivalent and laptops), and I want them to at least be able to isolate the year or decade they time-jumped to.
I was planning to use Barnard's Star as the easiest reference. Am I wrong? Is there an easier way?
https://oneminuteastronomer.com/8869/barnards-star/
Barnard Star’s main claim to fame is its large proper motion, the angular change of its position across the sky. It moves about 10.4” per year, more than any other star, which is a result of its true motion through the galaxy and its proximity to our solar system. Over an average human lifespan, the star moves about a quarter of a degree or about half the diameter of the full Moon. In astronomical terms, that’s mighty fast. - See more at: https://oneminuteastronomer.com/8869/barnards-star/#sthash.xGxKkwnN.dpuf
This is what Ensign Kim (Star trek Voyager) should see in 1996 if using Barnard's Star. Sorry about the zoom factor I wanted to show the Ophiuchus constellation.
Kapteyn's Star is second highest then Groombridge 1830 third highest proper motion are also possible choices.