Can someone please clarify!!!!!!

[stargazer1980]

I was out observing last night with my Celestron SLT114 and thought id take a look at alcor and mizar ( a visible double star to the naked eye) and easy to split in 32mm EP!

So how come whilst observing i saw another star extremely close to alcor, i could hardly split it with my 6mm EP! I did not know that it was another double star in its self or is it? Is it new or has it always been there as i have never seen this before and ive seen alcor and mizar loads of time before!

Can anyone please shed some light on this for me!

Have i found a new double star! Oh and they were different colours tooo!!!!!!!!!

Darren:)

[stargazer1980]

Just wanted to say also that i have checked on SN and stellarium and they only show alcor and mizar as the only 2 stars there! I guarantee you if you look tonight you will know what i mean!!

Darren

[Andrew*]

Have i found a new double star!

That I doubt!! Sorry. It's in SN pro. Mizar is a double, 10" separation between the two, a is mag 2.2 and b at mag 3.8.

Andrew

[stargazer1980]

so thats alcor and mizar correct???

[Andrew*]

No, that's Mizar and zeta Ursa Majoris. Alcor is way way up to the left

Here's a screenshot. Not sure the FOV of the image, but it's pretty small!

HTH

Andrew

[stargazer1980]

Ah thats better thanks for clearing it up lol! Feel stupid now

Thought that alcor and mizar were the double!!!

Darren

[Andrew*]

SORRY - I'm really wrong!! :oops:

They are in fact only an optical double star (or whatever the word is - they appear to be close together but in fact light-years apart). Mizar and Alcor are a genuine double and in reality quite close together.

Mizar and ZUM appear close to each other from our perspective.

Andrew

[geppetto]

Darren, out of interest, have you got your software set such that it's only

showing the bighter stars say around mag 5.?

There is a mag 7.5 star between thoes two which your software might not

be showing

[Andrew*]

ah - he's right:

Andrew

[jonifive]

ah - he's right:

He usually is......he knows his stuff does our Phil.

JV

[Astroman]

Alcor and Mizar are an amazing "pair". It's actually one of the more complex systems on the sky. Mizar is a double star system in orbit about the common gravitational point of itself and Alcor. Each of these stars has a spectroscopic star around it, as does Alcor. So, Alcor has a close companion, Mizar does too and, not to be left out, so does Zeta! So it's actually 6 stars in orbit around each other.

[proflight2000]

I got a pretty nice book the other week called observing and measuring visual double stars, must admit the learning kerb is a little high for a man of my intellect but it came with a free cd listing all the doubles ect from the US Navys observertory. I thought I would delve a little further into the theme of things and I can thouroughly recommend it to anyone who has not got a copy. It is edited by Bob Argyle and is in the patrick moore practical astronomy series.

Now to apply for my triginometry course (and a spelling course)

[lunator]

It's a great book.

My copy is very worn.

If you go onto the WDS website

http://ad.usno.navy.mil/wds/wds.html

And send Brian Mason an email he will send you the lastest WDS catalogue dated 2006.5 (he has loads)

The one in the book is from 2004.

You can also download the whole WDS from the website if you want.

Cheers

Ian