[AZ-Observing] Re: Thunderbird Park Star Party 10 May 2008

Mizar Aa and Bb are both pretty close in.  The Aa pair takes only 20.5386
days to complete, while Bb takes 182.3 days.  That makes them both closer to
the primaries than earth is to the Sun.  There is an unseen 5th star with a
period of 1,350 days.

A scale model might help.  If the sun were reduced to the size of a
baseball, Mizar A would be 8.4 inches in diameter, the same size as Mizar B.
A and B would be 1.93 miles apart.  Aa would be 3.94 FEET apart and Bb would
be 16.88 feet apart. I don't think any telescope on earth (or even Hubble)
could resolve the Airy disks of either of the spectroscopic pairs.

Smart people, liking those double stars!  (They are my favorite study next
to galaxies, which require totally different skies and conditions).


Richard Harshaw
Cave Creek, AZ


-----Original Message-----
From: az-observing-bounce@xxxxxxxxxxxxx
[mailto:az-observing-bounce@xxxxxxxxxxxxx] On Behalf Of Dan Heim
Sent: Sunday, May 11, 2008 5:05 PM
To: az-observing@xxxxxxxxxxxxx
Subject: [AZ-Observing] Re: Thunderbird Park Star Party 10 May 2008

Jeff,

DFAC was doing an Astronomy Night for the Boulder Creek High School
Astronomy Club, Saturday night up here at Heimhenge.  I too was surprised by
the reactions to Mizar A/B, which seemed to be one of their favorite
objects.  Of course, there were the usual "ooo's" and "ahh's" over Saturn
and the Moon, but they really seemed to like the double star thing ...
perhaps because most had never before encountered the concept of a double
star.  I don't know.  When I explained about each of the stars being
themselves double (albeit spectroscopic) that wowed them even further.
Several asked "How big a scope would you need to see the double double?"  I
had no idea, so I just said special instruments were needed, i.e., a
spectroscope, and that they couldn't be split with just a telescope.  Did I
lie?  Couldn't find the answer on the web when I searched later.

Dan Heim
President
Desert Foothills Astronomy Club
http://www.dfacaz.org


----- Original Message ----- 
From: "Jeff Hopkins" <phxjeff@xxxxxxxxxxx>
To: <az-observing@xxxxxxxxxxxxx>
Sent: Sunday, May 11, 2008 1:15 PM
Subject: [AZ-Observing] Thunderbird Park Star Party 10 May 2008


> Saturday evening an estimated 250 people showed up for the SAC spring
> Thunderbird Parkk Star Party. There were a couple dozen telescopes.
>
> I showed the Moon, Saturn and Alcor (with the double star Mizar) to
> many people. There was a continuous line of 20 to 30 people from dark
> to 9:30. Surprisingly people seemed more interested in Alcor than the
> other objects. I may need to get a tracker for my DOB as I was worn
> out between putting in the step stool and taking it out of the way
> for kids and adults (if only I could sort the viewers by size) and
> having the recenter things every couple of minutes.
>
> I'm less than impressed with the Park Commission. I do not think they
> talk to each other. It took awhile to gain access as they had locked
> the gate and noone had a key. I think they ended up using bolt
> cutters.
>
> All in all, it was a beautiful night and everyone seemed to have a
> great time.  Jack Jones did a good job!
>
> Jeff
> -- 
> Jeff Hopkins
> HPO SOFT
> Counting Photons
> http://www.hposoft.com/Astro/astro.html
> Hopkins Phoenix Observatory
> 7812 West Clayton Drive
> Phoenix, Arizona 85033-2439 U.S.A.
> (623)849-5889
> (623) 247-1190 (Fax)
> www.hposoft.com
> --
> See message header for info on list archives or unsubscribing, and please
> send personal replies to the author, not the list.
>

--
See message header for info on list archives or unsubscribing, and please 
send personal replies to the author, not the list.

--
See message header for info on list archives or unsubscribing, and please 
send personal replies to the author, not the list.

Other related posts: