Stacking Eta Leonis

On October 3, 2002, I had to take my car into the shop early. Since I had been trying to take a series of images showing a full lunation, I figured I would just get up a bit earlier and take several shots of the moon before driving to the garage. By pure dumb luck, I was shooting right through the time when Eta Leonis was occulted by the Moon. Additional dumb luck allowed me to span a range of exposures which allowed Eta Leonis to show up in some of the images. It wasn't until a week later when someone posted an animated GIF of their web-cam images that I realized that I had been shooting at just the right time to capture the event. Going through the negative scans, I found that the first set, at 1/30 second showed nothing. But the subsequent sets showed both Eta Leonis near the lunar limb it's approach and merging with the lunar limb!

The film used was Kodak Gold ISO 800, which was probably not a good choice due to it's graininess. However, I was using Michael Covington's exposure guide from his book, Astrophotography for the Amateur, and the exposures for ISO 800 speed film were already on the what I felt were a bit long for my f/12.1 Mak-Cas. I have subsequently begun to take pictures using Kodak T-MAX black-and-white film which seems to have much better grain and tonality. The color images of the moon don't have enough distinct color to warrant using color film, anyway.

Semi-raw image of Eta Leonis approaching Lunar Limb
Otbjec Moon, Eta Leonis
Location Forest Hills, NY
Time 2002-Oct-03 c.0544 EDT
Camera Pentax KX
Telescope Orion 127mm f/12.1 Maksutov-Cassegrain
Film Kodak Gold, ISO 800
Exposure 1/8 sec
Processing PWP Histogram normalization, convert to black-and-white, crop.

Can you see that tiny little dot hanging just above the lunar limb at about the 1:30 position? That's Eta Leonis. I call the above "semi-raw" because the original scans were color scans from the color negatives and the histogram was rather compressed. I used PWP normalize the histogram and then converted the image to black-and-white. I later cropped and scaled the image down by a factor of two in order to display it. Below is the a different cropped version at a 1:1 scale where you can see Eta Leonis a bit more clearly.

Semi-raw image of Eta Leonis approaching Lunar Limb
Object Moon, Eta Leonis
Processing Same as above, cropped here to show detail at 1:1

My habit with the lunar pictures has been to take four at each exposure as insurance against vibrations, mistakes, and general bad luck. If all four come out (most of the time), then I have four images which can be combined to reduce the noise level. Here's what this image looks like after averaging all four images, which were taken within 5-10 seconds of one another.