h1

No way

July 27, 2006

Last night I had planned on taking advantage of an opportune time to observe Pluto.  Yet, as the hour drew near so did the realization that hauling the 12.5 inch dobsonian about three miles for a marginally dark enough spot which would possibly produce the planet to my eyes was just too much of a gamble.  A dark sky spot on Mt. Pilchuck where I once nabbed the planet years ago is an hour trek each way and I didn’t feel like messing with that either.  This isn’t so bad though.  It made me aware again of one of the great things about this hobby/obsession. . .for most things there are more than plenty of times ahead to try for them again.  The night wasn’t wasted, however, and an attempt although one I knew would fail, was made to see Pluto.  Enter “Sneaky,” my 114mm reflector.  Scopes of this size have captured the planet before, but only under the best and darkest of skies.  I didn’t have nearly these conditions.  What I had was a desire to look exactly where the spot where Pluto was laying in wait for me yet knowing all along that he was placed 4 magnitudes beyond my capabilities for the night.  I looked and looked, jiggled the scope, used an eyepatch, went to a 6mm and then a 3.8mm EP to attempt to darken the sky sufficiently (which I knew was not gonna snatch the missing 4 magniudes). . .in short I tried all the tricks knowing that none would work.  Not surprisingly, my doomed efforts were very satisifying.  After all, it was a GOOD time at the telescope and that to me is what is important.

Question?  Am I the only one who occasionally goes after objects that all logic says are unobtainable?

h1

Good enough

July 12, 2006

It is obvious that there seems to be a compulsion for perfection in the spare-time activity named amateur astronomy. Strehl ratio, undercorrected and overcorrected objectives, baffling or not baffling the tube, high tech focusers — all would seem to be on the minds of many amateurs. Whatever happened to the concept of “good enough?” “Good enough” is good enough. “Good enough” will get you to the eyepiece more often and without perfection goals that will never be completely squelched. A well-maintained scope with no more than decent optics (by perhaps surprisingly low criteria) on a fairly stable mount will bring much happiness. It will also bring something else. . .peace of mind.

h1

The Ordeal

June 28, 2006

I started this morning by setting up the scope outside and turning on its fan to run all day; wanted that mirror to be in perfect thermal equilibrium by night fall. . .fourteen hours of fan action should do the trick.  At this point the sun is less than ten minutes away from setting and Jupiter is what I have been looking forward to observing.  Why?  Because it will be visible and positioned wonderfully for observation most any second now plus it won’t be dark enough to view DSO’s productively until nearly midnight.  Midnight usually finds me sound asleep and no doubt it will tonight also.  But I am heading out the door as soon as this posts to grab probably what will be the first of three brief observations of the planet over a perhaps a ninety minute time frame.  And you know what?  The few minutes which these observations will at most total somehow justifies the ordeal.

h1

Do you really need a barlow?

May 10, 2006

I don't own a barlow; don't see a need. Last night, I was viewing Jupiter with my 12.5 inch dobsonian (f/4.8) and was treated to some incredible views at 404x. This magnificaion was realized using a 3.8 Ultrascopic EP from Orion. The eye relief for this little fellow is more than comfortable for me and I suppose it is my "barlow." As far as the 50x per inch thingie, the nights are few for me which present good enough sky conditions to even push the magnification to the 400x level. But last night, I saw old Jupiter like I seldom have. The GRS was about the same color as the average cloud markings, yet the thin bordered outline it presented was astounding. Also, there was MUCH going on between the two major bands. A transit was also happening with Europa. Very satisfying. Switching to a 9mm Expanse EP, all of the aforementioned was still quite visible. Only smaller (duh!). Magnification isn't the most important ingredient for me in the mix leading to a truly satisifying and info packed observation. The prime ingredient is the overall condition of the sky at the moment.

h1

Celestial pocket globes

May 5, 2006

globe221.gifOne of the objects shown on the PBS show “Find!” tonight was an eighteenth century pocket globe. At an estate of a woman in the northeastern part of the United States, was a baseball-sized, genuine sharkskin case. This case separated into two halves which enclosed a nicely rendered globe of the Earth. On the inside of the globe-enclosing sharkskin case was the night sky. . .much like a mini planetarium. The object was appraised by the two blond-haired twins Leigh and Leslie Keno (stars of the show and originally from “Antiques Roadshow”) for thousands of dollars.

Here is a little information about a fine example of one of these globes from the Lanman Globe Collection
(http://www.library.yale.edu/MapColl/globes.html):

snip>>
c. 1818, James Newton, London
Globe 22
Newton’s Improved Pocket Celestial Globe. London.

In the seventeenth and eighteenth century, many people who could afford it carried pocket watches. As time went on, people took to carrying “pocket-sized” versions of other items such as barometers, and even globes. some were either mounted on stands like conventional globes, others were enclosed in special cases to make them more portable, as this one was. The first one is believed to have been made by the British mathematician Joseph Moxon in the late 1600s, and the Newton family was one of the many British firms who produced such globes. Their London firm was founded by James Newton (probably the father of the James Newton who made this particular globe), who was born in 1748.

This globe is only 7.6 cm in diameter. It is enclosed in a spherical case of shagreen (sharkskin) with twelve colored, engraved, celestial gores pasted inside. The case is held together by a hinge, and can be locked with two hooks.
<<unsnip

In conclusion, here is a link to a couple of images of this item:
http://www.library.yale.edu/MapColl/globe22.gif

Follow

Get every new post delivered to your Inbox.