On the tenth day from Hungary

C/2020 F3 (NEOWISE)

On March 27, 2020, for the inhabitants of the northern hemisphere, the most spectacular comet of the past two decades was discovered by NASA’s infrared space telescope program (NEOWISE). It was an exciting spring, as after two hopeful, eventually disintegrating comets, we hoped this comet would survive its perihelion.

The really great excitement began on June 22, 2020, when a comet heading for its perihelion (44 million kilometers from Sun) appeared on SOHO’s solar recordings. In the images of the spacecraft, a “healthy” and brighter-than-expected comet was observable. Barely ten hours after the perihelion, at dawn on July 4, 2020, we were able to observe for the first time from Hungary. The comet was almost lost in the light of dawn and could be seen only at a height above the horizon of 4-5 degrees.

The following mornings were in an increasingly favorable position and fortunately there was no complaint about the weather. The appearance of a comet with a magnitude of about 1.5-2 quickly crawled through the press and more and more professionals and laymen turned their cameras to the sky. For the under-thirty (even if some saw C/1995 O1 (Hale-Bopp) as a toddler), it was the long-awaited comet. As a teacher, I saw it as one of the greatest opportunities of my life, as spending my summer vacation could only be prevented by the weather. I vowed to take pictures of our celestial wanderer whenever I could (result: 48 days, 18 nights photographed, 122 GB of data, 3766 image files).

Each occasion had its own charm. At dawn on July 8, 2020, it was observed along with an amazingly sized NLC (night illuminated cloud) that if one saw with their own eyes, one would not forget for a lifetime. The tail grew longer and longer and its curvature became clearer day by day. It was a great pleasure to be able to deploy my telescope for the first time on July 11, 2020, with which I could detect even a faint gas tail at the time. On July 13, I had my last morning observation. After that, I tried in the evening sky. By photographing the comet, which had become circumpolar, my trouble accumulated in the following weeks. Unfortunately, with a few exceptions, it was an overcast or veiled sky that made it impossible to take photographs. The full moon in early August didn’t really help either, by the time its phase had diminished, by which time the comet had faded quite a bit, looked lower and was starting to take on the look typical of average comets (round green coma). I did my last observation on the evening of August 20, 2020, when I estimated its brightness to be only 7.4 magnitude, and its appearance was a shadow of July itself.

The daily movement of the comet in the last dawns created more and more unfavorable observation conditions for me, which was somewhat detrimental to the planned composition and the expected quality. The next day, I was already trying to capture the comet in much better conditions in the evening sky. Back then, I was still enthusiastic about planning the evening compositions, I didn’t think I would hardly have the opportunity to realize because of the clouds. The structure of the gas tail was also shown in the image (it was one of the most detailed Hungarian image at the time), but the stretch marks in the tube were an even more interesting phenomenon. These bars point in the direction of the Sun. Their source is not the core but the "bottom" part of the nozzle, which contains large particles. Nowadays sstronomers still don’t really understand when and how these big pieces leave the coma.

Interestingly, the comet’s tail length could reach 60 million kilometers, while its core was only 5 km in diameter. Analyzing the comet's orbit the C/2020 F3 (NEOWISE) will return in the second half of the 9100s. Thank you for the unforgettable experiences!


C/2020 F3 (NEOWISE)




R.A. 07 h 10 m 32 s Dec. +44° 36′ 07″



Distance from Sun: 

62 million km

Distance from Earth:

125 million km

Apparent size:

Coma: 4';
Dust tail: 4° (PA 335°); Gas tail: 5° (PA 345°)



Sidereal period:

6,900 years


66 km/s




13/07/2020 01:12-01:20 UT

Total exposure time:

5.5 minutes


Tápióbicske, Pest, Hungary


Nikon D3300


AF-S DX Nikkor 55-300mm f/4.5-5.6G VR


Sky-Watcher EQ6-R Pro GoTo

Focal ratio, length:

f/4.8, 100 mm




11 x 30 s








Astro Pixel Processor, PixInsight, Adobe Lightroom, Adobe Photoshop




Location in the Solar System

C/2020 F3 (NEOWISE) - 13/07/2020

Main objects: C/2020 F3 (NEOWISE)