Comet Johnson, May 15, 2017, 02:00 UT

Comet Johnson, May 15, 2017, 02:00 UT. 28×180 sec @ ISO 3200, Canon T3, Televue TV-85 at F/5.6. Star-Freeze version.
Comet Johnson, May 15, 2017, 02:00 UT. 28×180 sec @ ISO 3200, Canon T3, Televue TV-85 at F/5.6. Star-Streaks version.

I made it out to my dark sky site again on Mother’s Day, 2017.  Mom’s house was on the way there, so I managed to visit with her before my imaging session, which worked out pretty well.

Comet Johnson was my only target on this evening.   I used my Canon T3 with no LP filter at ISO 3200 with 3 minute sub-images.   That was about max for this particular night in that area of the sky.   A few high clouds interrupted me after about 8 shots, but I was able to continue shooting after they moved on.

I was hoping to catch a glimpse of the ion tail with a single exposure, but no luck in that department.   The LP dome to my northeast that the comet was embedded in was the limiting factor here.   Maybe the LP filter would have let me use longer exposures and I might have been able to detect the ion tail like that.

The 3 minute subs let me track the stars with only minimal pseudo-nucleus smearing, but anything longer and I would have had to track the comet.   That makes it harder to do star-freeze processing if the stars are trailed, however.   I either have to fix the trailing in post-processing or shoot a set of star-tracked sub-images.

Comet Johnson, May 15, 2017, 02:00 UT. 28×180 sec @ ISO 3200, Canon T3, Televue TV-85 at F/5.6. Close-Cropped Star-Streaks version.

5 thoughts on “Comet Johnson, May 15, 2017, 02:00 UT”

  1. Are those the Alkalurops (Mu Bootis) in the upper left corner? Thank you for the image. I was out during the weekend using my 8 SCT (w/GoTO) and I think I found the comet near Mu Bootis (SAO 64687). As I was tracking the comet, I noticed that Mu Bootis moved into the telescope field of view.

    1. Yes, that is Mu Bootis, I believe. They make a pretty pair and add a little extra to this comet image, in my opinion.

  2. Hi, may I have permission if I republished your image of Comet Johnson and Mu Bootis in our astronomy club’s newsletter. I have my own image taken through a 6 inch SCT with the comet and Mu Bootis in the same field but it is nothing like yours. I would like to show your image for contrast. Our newsletter is offered free of charge to our community and we use it as outreach. Our club, the Astronomers of Humboldt is a 501c3 educational nonprofit. I would credit you and link back to your website. Thank you for your consideration.

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