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Walter's LogBook |
| M57 Star Magnitudes |
Jean Francois Mourron posted a message to the AAVSO list on July 15th saying he had imaged the M57 field and seen a star that was not present on other images. He gave the URL for an image showing the suspect star, with various star magnitudes labelled.
Upon checking my image archive I found that I had imaged M57 on the following nights:
The suspect star was not present in any of these. It was fun to be able to see the magnitudes of various stars in my images, and I have included two below to show how deep I am going with my suburban imaging. I was quite pleased to see that I am reaching 18th magnitude (just)! The 17.9 magnitude star starts to become reasonably "solid" around 6.5 minutes exposure with the one-shot colour camera versus 3.5 minutes with the mono camera.
| M 57 | 40½ minutes (81 x 30s) |
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| M 57 (10" f/6.3 LX200) with an MX5C CCD camera. | |
| M 57 | 3½ minutes (7 x 30s) |
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| M 57 (10" f/6.3 LX200) with an MX5 12-bit CCD camera. | |