The stars a Draconis (c.2700 BC) and B Ursa Minoris (c. 1100 BC) share
an astronomical distinction from antiquity that they will share with a
Lyra in many centuries (c. 14000). Identify the distinction and name
the stars by their common names.

Hi lisanne,

What an interesting question to be asked on Google Answers! I've been
fascinated with astronomy for a long time myself: and north star
precession is especially fascinating.

For a primer on 'precession', please see:
http://www.crystalinks.com/precession.html

I was able to find a few sites of interest, including some diagrams
that help explain the fact that each of the three stars you mentioned
was the "north star" at a particular point in time.
http://www.astro.wisc.edu/~dolan/constellations/constellations/Ursa_Minor.html

a Draconis - It was the Pole Star around 2700 BCE. This star is
commonly called Thuban (the Arabic name for constellation).
http://www.dibonsmith.com/dra_a.htm

B Ursa Minoris - shortened form of "north star" (named when it was
that). This star is commonly called Kochab.
http://roland.lerc.nasa.gov/~dglover/dictionary/tables/table7.html
http://www.dibonsmith.com/umi_con.htm

Lyra, or "The Swooping" (Eagle) (or Lyrae) will be the "Pole Star"
around 14,000  years from now. This star is also called, "Vega"
http://www.astro.wisc.edu/~dolan/constellations/hr/7001.html
http://www.dibonsmith.com/lyr_con.htm

In short, all three were (or will be) the pole star.

Thanks for such an interesting question--and thanks for using Google
Answers!


Search terms:

north star precession
"beta Ursa Minoris"
"a Draconis"
precession

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Clarification of Answer by legolas-ga on 22 Nov 2002 18:22 PST

Thanks for the 5-stars! Glad I could be of help!

Thank you, very nice!

Part three of the answer is wrong. Lyra is a constellation, a (alpha)
Lyrae is the star Vega, found in Lyra. They're not synonymous. Also,
Lyrae is the genitive case of Lyra; again, they're not synonymous.

Ian G.