clear sky chart

Job 9:9

Job 9:9-10
9 He is the Maker of the Bear and Orion,
the Pleiades and the constellations of the south.
10 He performs wonders that cannot be fathomed,
miracles that cannot be counted.

Thursday, March 24, 2011

127mm Refractor 2nd Star Test & Clock Drive

Right after sundown, I went out and star tested the refractor again after my adjustments to the optics.  Tonight's subject was Sirius, and the image in the eyepiece was the same across the field when using both the 25mm plossl as well as the 9mm plossl eyepieces. I am therefore quite pleased with the results so far.

<Added 3/25> ' While I was observing Sirius, I noticed a very faint star just outside of the glare of the main star.  Could Sirius be a double?  After researching online and discovering that it is, I decided to add this observation.  I didnt think a lot about it at the time.  I'm still not 100% certain that what I saw was Sirius B or a nearby star, it did have all of the properties - Very dim in respect to Sirius, very close, but I also read where it is very difficult to observe, and was discovered on a very large aperture refractor.  I therefore am still uncertain that what I actually saw was the companion, even though it met all of the criteria.  I observed using the 9mm eyepiece.  It did appear as a tiny point of light. At magnitude 8.5, it would have been visible.  I dont rule it out, but I do remain skeptical as to whether what I saw was indeed Sirius B.'

I homebuilt a clock drive out of a stepper motor and misc gears scarfed from an old HP Deskjet 600 printer.  The pulse generator consists of a 555 timer, and the 4 phase output was generated by a 74LS194 TTL IC driving a ULN2803 which contains 8 Darlington power transistor drivers, 2 in parallel per phase.  The 555 oscillator has a variable frequency controlled by a potentiometer, and the phase is reversible by toggle switch. (This reverses the motor direction)
I used this circuit to scratch build mine on a piece of perfboard:

I am pleased to report that using the 9mm eyepiece, I can keep Sirius centered in the eyepiece for an extended period of time.

I will attempt to photograph Saturn this evening.  I'll be able to stay up a bit later than usual, as I wont have to be at work tomorrow until 2 hours later than usual.  We have crystal clear skies tonight, although it is quite cold, about 20F.

Any images that I take of course will be posted here.


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