2018-07-10: GOOD PLUTO HUNTING

I think I saw Pluto back in the 1980's with my trusty orange tube C8 telescope, but I'm not sure. All we had were paper charts back then, and unless something as dim as Pluto was near something fairly bright it was pretty hard to verify that you were really looking at the right object. I'm pretty sure I never took a picture of it. There is an outreach star party at the local college observatory every month. I've been showing up the past few months bringing little bits and pieces of equipment to entertain the masses. In the summer it usually lasts until 10:00 or 10:30 with stragglers until 12:30 or 1:00am. At about 11:00 or so I got out my Canon T6i and had a mini photo shoot with my Celestron EdgeHD 800. I'm still trying to pin down why some 20-30 seccond pictures with my Celestron Evolution mount look fine, and most don't. It has something to do with balancing.

Where's Pluto? Above is two images of the area around the "bright" star 50 Sgr. The bright object is 50 Sgr and it is a 5th magnitude star that you probably wouldn't be able to see in your everyday backyard in town. It shows up really nicely in a 20 second long photograph. The top picture was taken on Saturday night as the star party wound down, and the bottom one was taken Sunday night. See Pluto? I knew it was somewhere in the area, but didn't know which "star" it was while I was taking the pictures. Plus, only the camera got to look at the stars. I just got to look at my iPad.

There it is! By looking at the planetarium program Stellarium, after I got home Saturday night/Sunday morning, I was pretty sure I had caught Pluto in the field of view of the camera. The picture the second night confirmed it. The top picture was a 20 second exposure at ISO6400, the bottom 25 seconds at ISO6400. Both were messed with a bit to make them look better and roughly the same brightness. Pluto's magnitude was about 14.3, so pretty dim. Stars dimmer than 17th magnitude showed up in the originals of these pictures...in just those few seconds. In the old film days that would have been impossible.

Fun little project! I didn't peek through the scope during this to see if my eyes could see Pluto, but I may try that next month. In theory it may be visible in an 8" telescope, but not by a lot, and it may not be dark enough at the observatory. The college just keeps adding more and more lights in the area.

THE END

2018-10-31