Observing Log for Mike Durkin
6/5/2021 about 9:30PM-1:30AM
Locust Valley, NY
Transparency: 9/10, Seeing 4/5
Temperature: 60-70 degrees
Equipment: 70mm Stellarvue refractor and Star Anayzer 100
Today I wanted to see if using the Imaging Source camera would be feasable for spectroscopy.
I initially started with Spica and also using a filter wheel to get some added distance between
the grating and the chip. That was too much distance, since I could not fit both the star and
the spectrum on the chip. After that I just attached the grating the the 1.25 inch nosepiece
for the camera.
The rest of the star I looked at were Vega, δ2 Lyr, δ Sco, Arcturus and Altair.
I did notice however that the chromatic aberration was significant, especially on the blue side.
I'm also not trilled with focusing. The mount wobbles quite a bit with this setup, so trying
to focus was a bit of guesswork. By adjusting the gain and frame exposure length, I was able
to get some fainter stars. I was trying to limit the frame exposure length to 1 second, where
I was able to get stars at least as faint as 4th magnitude. Perhaps I can do a little fainter.
Next attempt to try to do spectroscopy I'll need to try something with the C8, maybe with a
focal reducer or the 16 inch Dob with drift scanning, but I'll be worried about the cable
length reaching the eyepiece.
On the plus side I was pleased at how long the laptop lasted on battery alone. But on the
negative side, the IC Capture software kept losing connection to the camera.
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Spectrum of a star from Jun 2021, which I think was Vega. Using a Star Analyzer 100 grating, 70mm Stellarvue refractor, and and Imaging Source camera. Video frames registered and stacked using Siril to make a FITS file. Analysis and graph generation was done using RSpec. The red line is my measured spectrum and the blue line is a reference spectrum of an A0V type star for comparison The chromatic aberration seemed to be significant, although I was pleased with some of the infrared lines that the camera was able to pick up. However I think there may be some issues with the calibration I used with RSpec. Some of the shorter wavelength lines don't align quite right with the reference spectrum. |
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Spectrum of Delta2 Lyr from Jun 2021. Using a Star Analyzer 100 grating, 70mm Stellarvue refractor, and and Imaging Source camera. Video frames registered and stacked using Siril to make a FITS file. Analysis and graph generation was done using RSpec. The red line is my measured spectrum and the blue line is a reference spectrum of an M4 type star for comparison. The chromatic aberration seemed to be significant, although I was pleased with some of the infrared lines that the camera was able to pick up. There does seem to be some issue with the calibration since most of the absorption lines don't quite match up with the reference spectrum. |
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Spectrum of Delta2 Lyr from Jun 2021. Using a Star Analyzer 100 grating, 70mm Stellarvue refractor, and and Imaging Source camera. Video frames registered and stacked using Siril to make a FITS file. Analysis and graph generation was done using RSpec. The red line is my measured spectrum and the blue line is a reference spectrum of an M type star for comparison. The chromatic aberration seemed to be significant, although I was pleased with some of the infrared lines that the camera was able to pick up. This graph used a different instrument response curve, which shows some of the absorption lines at the lower frequencies better, but the curve doesn't quite match what an M star should be. |
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Spectrum of Delta Sco from Jun 2021. Using a Star Analyzer 100 grating, 70mm Stellarvue refractor, and and Imaging Source camera. Video frames registered and stacked using Siril to make a FITS file. Analysis and graph generation was done using RSpec. The red line is my measured spectrum and the blue line is a reference spectrum of a B type star for comparison. I was not able to use the same instrument response curve that I obtained from Vega, which was disappointing. I'm also disappointed that I was not able to see any of the spectral lines other that Hydrogen alpha. |
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Spectrum of Altair from Jun 2021. Using a Star Analyzer 100 grating, 70mm Stellarvue refractor, and and Imaging Source camera. Video frames registered and stacked using Siril to make a FITS file. Analysis and graph generation was done using RSpec. The red line is my measured spectrum and the blue line is a reference spectrum of an A7 type star for comparison. For this star, I was focusing more on the hydrogen beta and gamma lines. The hydrogen alpha line is probably a little out of focus which may explain why is has been broadened. |
6/4/2021 about 11:00PM-12:00AM
Locust Valley, NY
Perhaps I can do a little fainter.
Transparency: 8/10, Seeing ?/5
Temperature: 55-65 degrees
Equipment: 15x70 binoculars
A humid night after a big rainstorm in the afternoon.
Measured variable stars RW Vir, FP Vir and α Her.
I also tried to see if I could detect M87 or any other of the galaxies in that area in the binoculars
but I couldn't see anything definitive. I also tried to see if I could detect M13 in Hercules and
I am pretty sure I did see it, although at that point I was only using my hands instead of a tripod
so the view was very shaky.
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