Visibility III / V
46P/Wirtanen is receding but still quite near Earth at a distance about 0,14AU. Here in first image Wirtanen is exposed at near UV 387nm narrowband wavelength, where about 30' diameter coma is visible. In the second image Wirtanen is exposed with R filter, where short dust tail of length 4' toward PA 210° is visible.
I used CometCIEF processing (Samarasinha, N. H., Martin, M. P., Larson, S. M, 2013. Cometary Coma Image Enhancement Facility, http://www.psi.edu/research/cometimen) to enhance 387nm stacked images to visualize possible rotation effect of cyanogen radical CN jets. In the third image/animation a CN jet PA is changing from ~210° to PA ~150°, about 60° clockwise during 75 minutes exposures.
Animation 1) Exposures with CN Semrock 387/15nm
- CometCIEF processed
- 5 frames each 3x300s, totalling 75 minutes, starting 2019-01-03 16:40 UTC
- CN Jet in frame 1 at PA ~210°, in frame 5 PA ~150°
Image 2) Exposures with CN Semrock 387/15nm
- 24x300s=2h bin2x2 1,68"/px
- Starting 2019-01-03 15:53 UTC
Image 3) Exposures with Astrodon R
- 30x20s bin2x2 1,68"/px
- Starting 2019-01-03 15:35 UTC