Tag: comet

Comet C/2022 E3 (ZTF)

This comet is all over the internet right now. Even mainstream media are reporting about the “Neandertal” comet with the poetic name C/2022 E3 (ZTF), which visited us last time 50’000 years ago. I was somehow losing hope to see or take a picture of this comet because the weather was constantly cloudy since October. However, on Sunday 30.1.2023 the sky cleared and I had a time window till 2 o’clock when the clouds rolled in. Unfortunately, the whole event was partially ruined by the Moon in the first quarter, so the best conditions occurred after midnight when the Moon was setting. Anyway, if you want to know why it has such a name, which resembles the password of the wifi at a hotel lobby? In fact, the comet’s naming follows the conventions. The letter C stands for a non-periodic comet, 2022 is the year of discovery, E refers to the month of discovery (first half of March), number 3 means a third comet discovered in this part of the month and ZTF stands for who or what discovered the comet. This specific comet was discovered by Zwicky Transient Facility. And why the nucleus of the comet glows green? Because most of the comets contain dicarbone (C2) molecules, which break apart by solar radiation, and during this process, the energy in form of light is released at carbon specific wavelength of 518 nm, which is a green visible light.

TelescopeSharpstar 94EDPH
Aperture94 mm
Focal length414 mm
MountRainbow Astro RST 135
AutoguidingZWO 178MM, QHY Mini Guide Scope
CameraZWO 6200MC @-10°C
CorrectorF4.4 Quad Reducer
Exposure51x120s, Gain 100, bin 1×1,

And here is an animation, which goes back and forth. For half of the animation (forward movement) I used 38 frames, each 2 minutes long, which means 76 minutes in total. This gives you an idea of how quickly the comet moves with respect to the background.

Comet C/2019 Y4 Atlas

The comet C/2019 Y4 Atlas was possible to spot in the constellation Lynx nearly two years ago (April 2020). This comet was discovered on 28th December 2019 by Asteroid Terrestrial-impact Last Alert System. The trajectory of the comet is suspiciously similar to another comet C/1844 Y1, which visited us nearly two centuries ago. Most probably it’s a fragment of the old visitor and the next opportunity to see this comet will occur in the year 2194.

It looks like a droplet drifting through the space. The picture was taken as the first light of the new telescope TS-Optics 150 mm f/2.8 hyperbolic Astrograph. This telescope disappointed me in its optical quality. So, don’t look at the stars in the corners. Postprocessing was quite tricky, but I somehow learned how to do it. In total, I stacked 44 exposures, each 3 minutes long, which means slightly more than 2 hours of integration time.

TelescopeTS-Optics 150 mm f/2.8 hyperbolic Astrograph
Aperture150 mm
Focal length420 mm
MountGemini G53f
AutoguidingZWO 174MM, QHY Mini Guide Scope
CameraZWO 071 Pro @-10°C
Corrector2.5" coma corrector
Exposure44x180s, Gain 94, bin 1x1,

Comet C/2017 T2 PANSTARRS

I missed the most prominent comet C/2021 A1 (Leonard) in 2021 due to permanent, constant, ever-lasting bad weather. In the last 3 months, I was able to see the star only through the holes in the clouds (except one night during our winter vacation in Laax). At least I have time to process the old data I took a long time ago. In 2020 I took pictures of two comets and here is one of them. It’s called C/2017 T2 (PANSTARRS) and on the 25th of May 2020 was possible to spot it, roaming in the constellation Ursa Major.

I was postponing the processing very long time because the comets are the most difficult object to process. There is a fixed background of the stars and deep space objects and the comet is slightly moving across the field. This means that the pictures must be registered twice and merged together afterward. Since I have plenty of time now, I was able to experiment, and here is the final image:

TelescopeNewton 254/1000 mm
Aperture254 mm
Focal length1060 mm
MountGemini G53f
AutoguidingZWO 174MM, TS 60/240 mm
CameraZWO 071 Pro @-10°C
CorrectorExplore Scientific HR coma corrector
Exposure34x180s, Gain 94, bin 1x1,

C/2015 V2 Johnson – My first comet

I was lucky and in the skies visible from my terrace appeared comet with poetic name C/2015 V2 (Johnson). Right now (2015-05) is slowly moving through the constellation Bootes not far from bright star Arcturus and it is “only” 120 million kilometer from Earth.

Because the comet moves differently compared to the background stars, one has two options how to photograph it. Either the telescope is pointed on stars and the comet is slowly drifting from the field of view or the telescope is pointed on the nucleus of the comet and due to the longer exposures the stars are trailing. I picked the second variant, in order to have the comet sharp. 3 minute exposures the stars are trailed into the oval shapes, but the comet is focused: