Astronomy Archives - Page 63 of 75

February 18, 2017April 13, 2017

The Molly Project Continues…

Things are coming together. I’ve recently painted everything that needed painting. If I had to do it over, I think I would have gone with stain but it’s too late to fret over that and I can’t rebuild something until I build it first. The red is a little darker than some of these pictures. More like the last picture than the second.

The first picture shows the mirror cell resting on the threaded rods that will be used for collimation. In the center of the cell is a fan and at the edge is a push button toggle to turn it on/off. The fan will be used to help the mirror reach equilibrium. I decided early on to go with a simple cell with 18 felt pads in the best locations for support.

Next, we see the 16″ (or 0.4 meter) mirror safely in the box resting on the cell. You can see the three collimation knobs that will allow me to collimate from the top rather than the bottom. Hidden behind the knob on the right is the push button from the other picture that will let me turn the fan on or off.

Finally, for this post, is the upper tube assembly with the secondary mirror and spider. Next I need to attach the board for the focuser and focuser itself. After that I can place the mirror box above and the UTA below on jig to determine the optimal separation and from that the length of the truss rods.

I’m hoping for first light in about a month.

February 10, 2017December 16, 2020

Penultimate Eclipse of the Moon

That sounds better than Penumbral Eclipse of the Moon which is more accurate. I was on my way out the door when I saw and remembered the eclipse so I ran back in for the camera. I was surprised about how easy it was to see this non-umbral eclipse. That said, look to the upper left near the Mare Frigorus area. That looks darker there. I don’t know how close the umbra came tonight but its easy to imagine it’s right there off the edge of the Moon.

January 31, 2017December 16, 2020

Moon, Mars, and Venus 1/31/2017

Here’s a picture of the left to right from this evening. The Moon and Venus are, respectively, always the second and third brightest objects in the sky not counting occasional supernova. Mars on the other hand gets really bright for a couple months every two years and then fades to relative obscurity. So it is here. The Moon is about 500 times brighter than Venus and Venus is perhaps 100 times brighter than Mars right now. For this picture, I used a regular DSLR with a 300mm lens set to 6400 ISO and a 1/80th second exposure. That was the shortest exposure that showed Mars and while longer exposures showed the ruddy color of Mars they also blew out the Moon and Venus. So, I had to compromise.