This comet was discovered by astronomers operating the Near Earth Object survey with the Wide-field Infrared Survey Explorer space telescope on 27th March 2020. The comet was then in the constellation Pupis, was magnitude 18, and 2 AU from the Sun. It moved north of the equator on 24th June but was only above the horizon during daytime. It became visible just after sunset or just before sunrise around the 7th July but was still only 20° from the Sun. A week later it became visible very low in the north throughout the night and was visible without optical aid in a dark location. It came closest to the Earth on 23rd June and thereafter it dimmed as it receded from both the Sun and the Earth. It will remain north of the equator until early September when it will be 1.5 AU from the Sun and magnitude below 15.
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I missed the comet when it first came readily visible from where I live and cloudy skies prevented visibility until the 19th and 20th of July. This picture of the comet just visible between my neighbour's house and my observatory was taken very late on the evening of the 19th. Thirty seconds exposure was too long for a static tripod even at this relatively short focal length so I had to correct that for the comet with Focus Magic. Date and Time: 19th January 2020 23:41 UT Camera: Canon 1100D Telescope: 70 mm SLR lens Capture: Canon EOS 30 sec. f/5 ISO800 Processing: PhotoImpact contrast 20 and reduction to fit the screen. Focus Magic correction of slight motion blur. |
| The following night was also clear so I mounted my camera on my GE mount so as to track the skies. This enabled me to take a series of pictures at a relatively long exposure and stack these in the standard way. Obviously the mount was tracking the stars, but the comet was quite close to the Earth so was moving relative to them. However by aligning the frames on the head of the comet, the stars appear streaked but the comet is sharp. The orientation is not quite correct; the comet's tail was more nearly vertical than this picture implies. The way I mount a DSLR on my mount gives me no flexibility of the orientation of the camera. As used here it was lying on its side so I have rotated the original image 90° but it needed to be slightly less than this, but I preferred not to use a fractional quarter turn. | |
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It is said that faint details, such as the tail of a comet, are more easily seen in negative images. I am not convinced that it is true for this picture, but you can see an inverted image by moving your mouse pointer over the picture. The reduction of the image to fit this page has resulted in most of the stars disappearing. The few that remain do show more clearly, I think, in the inverted image. The slight trail in the stars caused by the movement of the comet also disappear with the reduction. If you would like to see the full-sized image before the application of the graded background removal, together with a negative version (which may appear first as your pointer will be over the image) click on the picture. (Press Back to return here.) Date and Time: 20th July 2020 23:17 to 23:26 UT Camera: Canon 1100D Telescope: 70-300 mm SLR lens set at 190 mm. Capture: Canon EOS 20 sec, ISO 1600, f/5 Processing: Registax. 20 frames, histogram 75-255, gamma 1.5 Custom software: removal of a graded background. |