💾 Archived View for gem.librehacker.com › gemlog › starlog › 20221107-0.gmi captured on 2023-12-28 at 15:37:44. Gemini links have been rewritten to link to archived content
⬅️ Previous capture (2023-01-29)
-=-=-=-=-=-=-
God gave us clear skies for a few hours on the evening of November 5th. The moon was very bright, making stargazing very difficult, but the cloud situation has been so poor that one must take whatever opportunities are available.
I spent some time looking at the moon with the H12.5 eyepiece. After that, I did another sketch of Jupiter. I recently bought a Night Sky Observation Logbook (ISBN-13 979-8687347891) which has made sketches neater and more fun.
Logbook - Jupiter Sketch (2022-11-05)
I also did a sketch of the starfield above Vega, in the Lyra constellation, using the H25 eyepiece:
Logbook - Stars above Vega (2022-11-05)
I was able to get the numbers on my main telescope, which is a Meade Jupiter 60AZ-M. This model has a 700mm focal length with 60mm diameter primary. So, with the different eyepieces, the magnification is as follows:
H25mm: 28x
H12.5mm: 56x
H6mm: 117x
Another interesting point I was trying to figure out was the field of view for a given eyepiece. The problem I ran into there is that I don't know the apparent field of view for any of the eyepieces, and couldn't find this information from an authoritative source online. From what I could gather though, it should be somewhere around 35 or 40 degrees. If I assume 35 degrees, and the aforementioned magnifications, the values come out as follows:
H25mm: 1 degree 15 minutes
H12.5mm: 37 minutes 30 seconds
H6mm: 17 minutes 56 seconds
In Stellarium, there was about 12 arcminutes between Jupiter and Callisto at the time of my observation, which took up a little less than half the FOV in my observation, so it seems like maybe apparent field of view for H12.5mm eyepiece at least is a bit smaller than 35 degrees, maybe around 30 degrees.
Someone on IRC suggested getting a 0.965 to 1.25 inch adapter, and replacing the Huygens eyepieces with Plossl types. I'm looking into that idea.
Tonight is a total lunar eclipse, and I would really like to see that. Two challenges I face are (1) I would have to get up around midnight, which is a difficult time to get up during the work week; and (2) the forecast is showing overcast cloud cover all night. So I'm hoping to give a report on that, but we'll see how God allows things to work out for me and for Fairbanks...
