New Storm Feature Found on Uranus

I have been informed by the well-respected European amateur Marc Delcroix that a new large-scale storm feature has been discovered in the atmosphere of the planet Uranus by American Blake Estes. The storm appears as a patch on the border of the bright northern polar zone and extends somewhat into the darker latitudes below it. Based on the observations made so far Marc has calculated the following “tentative ephemeris” for the storm. The main point of note is the estimated central meridian transit times for the storm; observations near these times on the dates given should help to tie down the exact rotation rate of the storm around the planet.
WinJUPOS 10.3.11 (Uranus), C.M. transit times, 2018/11/14  10:06
Object longitude: L = 270,0° – 24,7470°/d * (T – 2018 Oct 09,5)
Output format: Date UT (C.M. of System 1)
——————————————————————————
2018 Nov 20   00:24 ( 323°)   16:49 ( 306°)
2018 Nov 21   09:15 ( 289°)
2018 Nov 22   01:41 ( 272°)   18:07 ( 255°)
2018 Nov 23   10:33 ( 238°)
2018 Nov 24   02:58 ( 221°)   19:24 ( 204°)
2018 Nov 25   11:50 ( 187°)
2018 Nov 26   04:16 ( 170°)
2018 Nov 27   13:07 ( 136°)
2018 Nov 28   05:33 ( 119°)   21:59 ( 102°)
2018 Nov 29   14:25 (  86°)
2018 Nov 30   06:50 (  68°)   23:16 (  51°)
2018 Dec 01   15:42 (  35°)
2018 Dec 02   08:08 (  18°)
2018 Dec 03   00:34 (   1°)   16:59 ( 344°)
2018 Dec 04   09:25 ( 327°)
2018 Dec 05   01:51 ( 310°)   18:17 ( 293°)
2018 Dec 06   10:43 ( 276°)
2018 Dec 07   03:08 ( 259°)   19:34 ( 242°)
2018 Dec 08   12:00 ( 225°)
2018 Dec 09   04:26 ( 208°)   20:52 ( 191°)
2018 Dec 10   13:17 ( 174°)
2018 Dec 11   05:43 ( 157°)   22:09 ( 140°)
2018 Dec 12   14:35 ( 124°)
2018 Dec 13   07:01 ( 107°)
2018 Dec 14   15:52 (  73°)
2018 Dec 15   08:18 (  56°)
2018 Dec 16   00:44 (  39°)   17:10 (  22°)
2018 Dec 17   09:36 (   5°)
2018 Dec 18   02:01 ( 348°)   18:27 ( 331°)
2018 Dec 19   10:53 ( 314°)
2018 Dec 20   03:19 ( 297°)   19:45 ( 280°)
2018 Dec 21   12:10 ( 263°)
2018 Dec 22   04:36 ( 246°)   21:02 ( 229°)
2018 Dec 23   13:28 ( 213°)
2018 Dec 24   05:54 ( 196°)   22:19 ( 178°)
2018 Dec 25   14:45 ( 162°)
2018 Dec 26   07:11 ( 145°)   23:37 ( 128°)
2018 Dec 27   16:03 ( 111°)
2018 Dec 29   00:54 (  77°)   17:20 (  60°)
2018 Dec 30   09:46 (  43°)
2018 Dec 31   02:12 (  26°)   18:38 (   9°)
2019 Jan 01   11:03 ( 352°)
2019 Jan 02   03:29 ( 335°)   19:55 ( 318°)
2019 Jan 03   12:21 ( 301°)
2019 Jan 04   04:47 ( 285°)
2019 Jan 05   13:38 ( 250°)
2019 Jan 06   06:04 ( 234°)   22:30 ( 217°)
2019 Jan 07   14:56 ( 200°)
2019 Jan 08   07:22 ( 183°)   23:47 ( 166°)
2019 Jan 09   16:13 ( 149°)
2019 Jan 10   08:39 ( 132°)
2019 Jan 11   01:05 ( 115°)   17:31 (  98°)
2019 Jan 12   09:56 (  81°)
2019 Jan 13   02:22 (  64°)   18:48 (  47°)
2019 Jan 14   11:14 (  30°)
2019 Jan 15   03:40 (  13°)
2019 Jan 16   12:31 ( 339°)
2019 Jan 17   04:57 ( 323°)   21:23 ( 306°)
2019 Jan 18   13:49 ( 289°)
2019 Jan 19   06:15 ( 272°)   22:40 ( 255°)
2019 Jan 20   15:06 ( 238°)
2019 Jan 21   07:32 ( 221°)   23:58 ( 204°)
2019 Jan 22   16:24 ( 187°)
2019 Jan 23   08:49 ( 170°)
2019 Jan 24   01:15 ( 153°)   17:41 ( 136°)
2019 Jan 25   10:07 ( 119°)
2019 Jan 26   02:33 ( 102°)
2019 Jan 27   11:24 (  68°)
2019 Jan 28   03:50 (  51°)   20:16 (  35°)
2019 Jan 29   12:42 (  18°)
2019 Jan 30   05:08 (   1°)   21:33 ( 344°)
2019 Jan 31   13:59 ( 327°)

The SPA, the BAA and Marc himself would welcome images of the storm to learn more about this new atmospheric feature. The best way to capture it is with a larger aperture telescope using a monochrome planetary camera equipped with an infra-red pass filter; however certain one-shot-colour cameras have excellent sensitivity in the infra-red and can also be used with an IR pass filter to good effect. The main point is to try and capture this new storm if at all possible. Uranus is reasonably well placed in the evening sky through November, December and into the New Year so I would encourage any SPA member with a telescope aperture of perhaps 8 inches / 200 mm or more and a suitable camera and filter to try. I will be happy to report any results in the section reports and to pass such images on to Marc to help him refine his calculations.
To quote Marc directly:-
“Indicate at least on the image,
– mid-time acquisition (UT)
– filter
– your name
and have a processing leaving the satellite(s) visible (do not raise the black level too much) so I could calibrate and measure your observations.”

I also include a link to a small animated gif file that shows the discovery images and will attempt to get the gif working here shortly.

http://alpo-j.asahikawa-med.ac.jp/kk18/u181022a3.gif

Alan Clitherow.

PS Sorry, but I am having trouble getting the link to work directly, please copy it into your browser to view the gif.

AC