Tuesday, September 15, 2009

September Nights

September is usually a great month in Ohio for clear skies.  The autumn skies provide a wealth of objects to observe!  If you get a chance to get out to a dark sky, please do.  In fact, many of us at the The Columbus Astronomical Society are planning to do just that!

The first thing you will notice when looking overhead is a glowing stream of light broken up by dark lanes.  This is our very own galactic home, the Milky Way.  What you are seeing is the combined light of billions of stars and in some places, obscured by intergalactic dust.  Take a pair of binoculars and sweep this region of stars and you will see thousands of stars across the field of view.  Occasionally, you may see clumps of stars together.  These stars usually are part of a galactic star cluster.  When stars are born, they hang around together during their early years.  Bound by gravity, they eventually start to drift off to form their own paths in the Milky Way.  About 5 billion years ago, this happened with our Sun.

Towards the south east during the evening, you may notice a bright star.  This beacon is Jupiter, the king of the planets.  With those very same binoculars, you can see Jupiter's orb and one of more "stars" close by in a line.  Those stars are Jupiter's moons, Io, Europa, Ganymede, and Callisto.  If you are so inclined, make a little drawing log and draw the positions of the moons in relation to Jupiter.  Galileo did the same thing 400 years ago!!

Towards midnight, the Milky Way starts to slide towards the west and the sky changes towards the autumn sky, dominated by Pegasus and Andromeda.  Pegasus is comprised of what is called the "Great Square" and Andromeda looks like a tilted Christmas Tree off to the side.  Andromeda holds a treasure called the Great Andromeda Galaxy.  This galaxy can be seen with the naked eye in dark skies.  And is very visible in binoculars.  Some day, billions of years in the future, Andromeda and our Milky Way are going to merge together.  Don't worry though, our solar system will probably come out of the merger unscathed.

Look towards the east and you will notice a grouping of stars.  This grouping of stars is called the Pleides, or the seven sisters.  A very nice object in binoculars.   Towards the northeast, there is a bright star called Capella, the brightest star in the constellation of Auriga.  Capella and the Pleides are part of the winter sky where Taurus and Orion resume their yearly battle above the frigid landscape below.  But that is for another time.

Clear skies and I hope you take time to look up and notice the Universe above you.

Two Observatories Saved from Wildfires

Thanks to the efforts of brave firefighters, two historic observatories have been saved from the wildfires in California.


Monday, September 7, 2009

Bearings done

I finished the bearings.  They are 21" in diameter and 1" thick.  On the 12.5", I routed some holes to give it a nice look.  With these bearings, I decided to try something different.  The bearings are made from two 1/2" pieces of baltic birch plywood.  I routed similar holes only one of pieces and left the other solid.  I think it looks nice.  I sanded them so that they are perfectly matched.  I plan to work on the secondary ring this week.

Also, I will not be painting these like I did on the 12.5".  I plan to keep it natural by putting a layer of clear enamel over it.  I think it will look good.  The rest of the scope will be the same however.

Sunday, September 6, 2009

16" Build officially started

Today I started cutting wood for the bearings.  The bearings are 21" in diameter and will be 1" thick.  Pictures to follow tomorrow when I finish up the bearings.

Thursday, September 3, 2009

16" Mirror Arrives safely

I picked up the packages that contain my 16" mirror, spider, secondary, focuser, and a little surprise: A Meade Coffee Cup!! (Thanks Richard).  You know, you don't really think about how big something is until you get it.  When I pulled the mirror out, it was kind of overwhelming to see it.  I did get a tape measure out and confirm that it indeed is 16" wide (instead of 18 or 20, hehehehehe)

The secondary was larger than I expected.  I measured it to be about 3 5/8" wide.  Pretty big for visual use, but not big enough to cause a problem (you want to stay between 20% to 25%).  I measured the spider and it is just about the right size for my purposes.

Now the fun begins!  I will start with the secondary ring and bearings, and then onto the mirror box.  I need to start getting stuff together to sell so that I can afford the truss system.  This is where I learn patience.  Pretty hard to do when there is a nice 16" mirror waiting to reflect some photons.

Cannot wait to start cutting wood!

Tuesday, September 1, 2009

16" Mirror on the way!

I just got confirmation that my new (to me) 16" mirror is on the way. The mirror used to live in a Meade 16" dobsonian and I plan to build a scope just like my 12.5" for it. Not too many differences really between them, but I will be documenting the build on this site. It may take longer because I need to build funds to buy some of the more expensive items (like the truss system from Moonlight Focuser which is an excellent product).  The spider and secondary is included from the old scope and I have no doubts that it will be fine for my purposes.  I originally was going to go with a Moonlight focuser which is my "dream" focuser, but in an effort to keep the cost down, I will be going with the Kineoptics HC-2.

Stay tuned for details of the construction.