My astrophotography 2021

CCD vs Film? Lots of time vs no patience? Alright, this is your place to discuss all the astrophotography what's and what's not. You can discuss about techniques, accessories, cameras, whatever....just make sure you also post some nice photos here too!
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hhzhang
Posts: 730
Joined: Sun May 10, 2020 4:11 pm
Favourite scope: 115mm APO

Re: My astrophotography 2021

Post by hhzhang »

LookingForScope wrote: Tue Nov 09, 2021 3:01 pm I see. I wish it was this easy to transport a newtonian.
It is never too late to get a small APO for imaging.
hhzhang
Posts: 730
Joined: Sun May 10, 2020 4:11 pm
Favourite scope: 115mm APO

Re: My astrophotography 2021

Post by hhzhang »

2021-Nov-9 Waxing Crescent Moon peeping behind the clouds. Really it was a cloudy evening.


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Last edited by hhzhang on Wed Nov 17, 2021 8:25 am, edited 1 time in total.
hhzhang
Posts: 730
Joined: Sun May 10, 2020 4:11 pm
Favourite scope: 115mm APO

Re: My astrophotography 2021

Post by hhzhang »

2021-Nov-16 evening. Venus has passed M22

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hhzhang
Posts: 730
Joined: Sun May 10, 2020 4:11 pm
Favourite scope: 115mm APO

Re: My astrophotography 2021

Post by hhzhang »

Comet 67P has gained brightness recently and stays in a favorable position near zenith in pre-dawn hours. But the annoying clouds!



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hhzhang
Posts: 730
Joined: Sun May 10, 2020 4:11 pm
Favourite scope: 115mm APO

Re: My astrophotography 2021

Post by hhzhang »

2021-Nov-18~19

One of the brightest close-approaches of an NEO this year. This early morning it was still approaching the 0.3856AU minimum distance (2021-Nov-21 19:20 UTC).

Two nights ago, it was at similar brightness and in the pre-dawn hours I tried to capture it with my small APO (70mmF4.8+ASI183MM), when the gibbous moon was low in the western sky and the object was also at a low altitude. I shot a few 30s subs but the images turned out not able to capture its image. I deemed that it might be too difficult a target for the small scope because of the unfavorable light pollution from the moon+SG lights, and also because of the fast motion of the object in the sky : 15'/hour means crossing 1" every 4 seconds, or 7.5" every 30s. Either the system can track the asteroid's move, or the image will see the light trailing and become too obscured under the background signal.

So I went to try it with the remote RH200 scope in Nambia under Bortle-1 night sky. I used the 2x2 binning so the pixel size became ~7.5um to counter the fast motion. With 12 subexposures stacked, here is the outcome

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Last edited by hhzhang on Fri Nov 19, 2021 8:28 am, edited 1 time in total.
hhzhang
Posts: 730
Joined: Sun May 10, 2020 4:11 pm
Favourite scope: 115mm APO

Re: My astrophotography 2021

Post by hhzhang »

2021-11-18

But Venus never disappoints. It travels into the southern Dipper asterism in Sagittarius.

I just received the digital edition of 2022-Jan issue of Sky&Tel which has a special article on Venus. I learned from it that the Venus's apparent trajectory has a 8-year cycle. So I look forward to seeing this Venus-Sagittarius encounter in 2029, hopefully under a real dark and clear sky!

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hhzhang
Posts: 730
Joined: Sun May 10, 2020 4:11 pm
Favourite scope: 115mm APO

Re: My astrophotography 2021

Post by hhzhang »

2021-Nov-20

Full moon night of clear skies after dusk. Went to shoot two asteroids of interest.

A. (279) Thule

Archetype for the Thule dynamical group: they orbit in the outermost edge of the asteroid belt in a 4:3 orbital resonance with Jupiter.


This stacked image shows its slight move over 1-hour duration in Pisces.


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B. (1902) Shaposhnikov
A large body among the Hilda group, those in 3:2 orbital resonance with Jupiter. Shorter semi-major axis than Thule asteroids. However, this Hilda object is like no other.

It is one of the last larger asteroids discovered in the main belt. ~80-90km diameter.

Its orbit has a relatively large eccentricity (0.22),causing it to swing much closer (3.1AU) to the sun at Perihelion and much further at 4.8 AU at Aphelion.

The 4.8AU puts its orbit overlapping with Jupiter trojans'. So this is a remarkable object: a large size asteroid of main belt with the largest Aphelion.

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hhzhang
Posts: 730
Joined: Sun May 10, 2020 4:11 pm
Favourite scope: 115mm APO

Re: My astrophotography 2021

Post by hhzhang »

Still fascinated with solar system objects.

2021-Nov-22 Thanks for the clear night!

Neptune and Triton, at 29AU distance from earth.

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(1902) Shaposhnikov
Finally managed to capture the motion of the special asteroid.
I also used this to practice longer, 2-min sub-exposures.

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With a total exposure time of 24 minutes, the image can reach up to 17.1 ~ 17.2 magnitude stars.

Next, a better capture of (279) Thule's moving position, 1 hour apart.
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No sure why the two galaxies are also shown in this total 13min exposure -- SIMBAD shows its magnitude of G 18.49 for 2MASX J01102971+0517498.
hhzhang
Posts: 730
Joined: Sun May 10, 2020 4:11 pm
Favourite scope: 115mm APO

Re: My astrophotography 2021

Post by hhzhang »

2021-11-27

C/2021 A1 is truly becoming the most prominent comet of 2021. It had been quite elusive behind the clouds in pre-dawn skies of Singapore. But this morning there was a moment of gap and I took advantage of it. Despite my mistakes (forgot to take flat frames, etc.), the comet image came out with a clearly visible tail to a bright nucleus.

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hhzhang
Posts: 730
Joined: Sun May 10, 2020 4:11 pm
Favourite scope: 115mm APO

Re: My astrophotography 2021

Post by hhzhang »

2021-Nov-30 to Dec-1 night

Finally, a largely-clear night came upon us in Singapore.

After sunset, I took an image of Pluto and combined it with another shot from a Nov 22 session. The apparent motion of this large dwarf planet at ~35AU distance is clearly visible.

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Last edited by hhzhang on Wed Dec 01, 2021 10:41 am, edited 1 time in total.
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