2007-01-31 08:30:54 · 6 answers · asked by Anonymous in Science & Mathematics ➔ Astronomy & Space
Do you mean the famous "DOUBLE" optical star in Ursa Majoris? The two members of this optical "double" are:
Alcor and Mizar (also collectively called Zeta Ursa Majoris).
This is NOT a PHYSICAL double, but rather just an OPTICAL "double" (as I wrote above) --- the two "stars" are at very different distances. What's more, examination at ever higher telescopic power (and then spectroscopically) reveals yet more multiplicites that involve REAL "physical doubles." By that latter term one means that they are physically orbiting one another.
All of these additional multiplicities were however unkown to ancient peoples who used to emply Alcor and Mizar (both their angular separation and the DIRECTION of the line joining them) as a test for warriors' eyesight.
Live long and prosper.
2007-01-31 08:43:56 · answer #1 · answered by Dr Spock 6 · 0⤊ 0⤋
All stars are "optical" in the sense that the emit visible light. I think you want to ask about "optical double" stars, which are stars that appear to be double to the naked eye.
If that's the case, the star you're looking for is Mizar, which is the middle star in the handle of the Big Dipper. Mizar's dimmer companion, which you can see on a clear night, is Alcor.
2007-01-31 16:52:13 · answer #2 · answered by Keith P 7 · 0⤊ 0⤋
Auds
2007-01-31 16:36:02 · answer #3 · answered by kenneth m 2 · 0⤊ 0⤋
www.Specsavers' R' Us.com
2007-01-31 16:46:17 · answer #4 · answered by pop c 2 · 0⤊ 0⤋
freddie
2007-01-31 16:35:36 · answer #5 · answered by Anonymous · 0⤊ 0⤋
which one? there are several
2007-01-31 16:46:31 · answer #6 · answered by Anonymous · 0⤊ 0⤋