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Ursa Astronomical Association

Telescopic comet Churyumov-Gerasimenko - 17.10.2021 at 00.05 - 17.10.2021 at 06.00 Orimattila, Artjärvi, Viestikallio Observation number 101826

Visibility III / V

Jorma Ryske, Etelä-Suomen kosmol. seura

67P / Churyumov-Gerasimenko presents his handsome almost 20 'long tail here, even though he is only a mag10 comet. 67P / CG is relatively close at a distance of 0.44au from Earth so Koma’s morphology is also starting to show. Figure 2 shows a 50 minute exposure with a narrow band cyan radical gas CN 3883Å filter treated with CometCIEF. It distinguishes two jets both in the direction of the normal tail PA 290 ° and also in the curved forward outgoing jet in the direction PA 110 °.

Picture 1) 20x60s, L / Clear filter, 2021-10-17 02: 30UT, FoV 28'x18 '

Figure 2) 10x300s, narrowband 387nm / 15nm filter, CometCIEF processed, 2021-10-17 01: 38UT, FoV 6'x6 '

Figure 3) Same as Figure 2, but no CometCIEF processing, 10x300s, narrowband 387nm / 15nm filter, 2021-10-17 01: 38UT, FoV 12'x12 '

Figure / Animation 4) 4 frames each 10x300s, narrowband 387nm / 15nm filter, CometCIEF processed, start 2021-10-16 23: 04UT --- end 2021-10-17 02: 30UT, FoV 8'x8 '

More similar observations
Additional information
  • Observation target
    • Comet
  • Visibility of the comet
    • Telescopic comet
  • Name of the observation target
    • 67P/Churyumov-Gerasimenko
  • Brightness in magnitudes
    • 10
  • Tail length
  • 20 arc minutes
  • Coma diameter
  • 3 kaariminuuttia
  • Weather
    • 3C, tuulenpuuskat heiluttivat kaukoputkea

Technical information

TS 305 / 1205mm Newton, TS KomakorrF4, QSI690 / ICX814, filter Baader Clear, Semrock CN 387nm / 15nm, Astrodon RGB Gen2, mount CEM60. FoV 36 'x 28'. North up, east left.

CometCIEF: Samarasinha, NH, Martin, MP, Larson, S. M, 2013. Cometary Coma Image Enhancement Facility,

Comments: 2 pcs
Federico Manzini - 18.10.2021 at 12.16 Report this

Very interesting image! Is the original image the one above?

Which spatial filter in CometCIEF did you use?

Thank you for your work

Federico Manzini (IAU MPC A12)

Stazione Astronomica di Sozzago (Novara) - Italy

Jorma Ryske - 18.10.2021 at 19.55 Report this

Hi Federico, I added original (except that original is of course fits but this is jpg) 10x300s 387nm/15nm filter exposure as image3 (FoV there 12'). This is the image I processed with CometCIEF using enhancement technique "Division by Azimuthal Median" to get image2.

Also I created an animation of four CometCIEF processed frames each 10x300s exposure with 387nm/15nm filter, so there is totally 40x300s exposures. First 1/40 exposure started at 2021-10-16 23:04 and last 40/40 exposure at 2021-10-17 02:25UT. Unfortunately one brighter star trail in the animations second frame was going through this possibly PA 110° CN jet, but the jet is more or less visible in all other frames.

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