My astrophotography 2021

[hhzhang]

2021-Sep-17

Now, this is daytime astrophotography.

<Last night's shooting was a bit disappointing. Almost empty-handed after a few tiring hours.> Today's evening is much worse. But I could take the time to process the catches this afternoon when I was admiring the blue-sky sunny Singapore scenery.

Didn't manage to capture a daytime moonrise. But this single shot probably makes it all worthwhile.

[hhzhang]

Hmm, I have figured out that my poor vision has been spoilt by colors often overly-done by cameraphones' "AI" nowadays. And I am quite inspired by a few outstanding B&W photographers (especially a few Vietnamese on Facebook's B&W Planet group). So, when I converted the above imagery into B&W, I felt immediately peace of mind.

[hhzhang]

2021-Sep-18

Waxing Gibbous Moon surfs the clouds

[hhzhang]

2021-Sep-20

Harvest moon, finally!



B&W is more to my like.

[hhzhang]

And Venus has finally crossed the border and entered Libra. Mercury on the other hand, has passed the highest point (greatest elongation east) recently, and is returning to the sun and will soon become a morning star together with Mars in Oct-Nov.

[hhzhang]

2021-Sept-21

Cannot miss photographing the harvest moon.

But my plans to shoot the moonset in the morning and the moonrise in the evening both failed thanks to the cloudy weather.

But that huge disappointment is partially compensated with some nice views of the colorful clouds painted by the moon ray.

<<中秋之夜，彩云追月>>







Hah! They resemble the celestial nebulosity but are illuminated instead by our lovely moon --- actually by reflected lights originally coming from the sun. So in a strict sense, these clouds are still illuminated by a star.

But what a difference! For nebulosity, you have to collect exposures of hours. Here, thanks to the quick motion of the clouds, I have to reduce shutter speed to a split second.

[hhzhang]

2021-Sep-22

Glad to see more sunspots



and slow but steady movement of the inner planets.

[hhzhang]

202-Sep-23

Today's biggest catch: green flash

Only in the digital darkroom process, I noticed it in the last picture of the sunset. The size is rather small here, but it gives me new hope.

[hhzhang]

And the sun's position relative to the September Equinox. Now I know my true west direction!



And the sunspots



And Venus-Mercury-Spica. The latter two will soon leave the evening sky stage. Venus is transiting Libra and will soon meet Scorpius.

[hhzhang]

2021-Sep-25

Had a great time (joy + disappointment) at Changi coast this morning.

Target 1: 8P/Tuttle -- a relatively bright comet -- and due to the fact it now travels near the sun (small 18deg elongation) and south of the equator, most northern hemisphere observers cannot observe it. But in Singapore we take advantage of our low altitude, which means the comet climbs to a good height in early twilight.

However, as usual, it all depends on the weather. Turns out this morning the easter sky was foggy with some thin clouds. I nevertheless used my intervalometer to take a number of shots, with the camera sitting on the sky tracker. A short test shot (~10s) showed a greenish spot on my screen (10x display). I was hurrying because the sky was almost shimmering in the twilight. Back at home, I realised I made a blunder: the tracker's balance weight hit a tripod leg just after two exposures -- and stalked there -- leaving all the rest exposures trailing the stars.

So I had to see what I could extract from the two 15-s exposures. And here is the 100% crop.



Thanks to the brightness of the comet, I think I captured a little fuzzy greenish ball.

If the weather cooperates in the next few mornings, I will go out making more attempts at this comet.

Well. Why I am a little fascinated with this comet? To name two reasons:
-- It is a contact binary
-- It is periodic but somewhat special

It is not a usual periodic: its orbit extends slightly beyond Saturn -- while most Jupiter-family comets are within the orbit of Saturn. So, it is relatively rare to be able to observe a Jupiter-family comet that travels thus far and being periodic. In the coming decade, we will probably see only a handful of periodic comets from beyond Saturn's orbit:

12P/Pons–Brooks 70.85y period: Next perihelion April 20–21, 2024
13P/Olbers 69.52y Next perihelion 30-Jun-24
55P/Tempel–Tuttle 33.22y Next perihelion 20-May-31
161P/Hartley–IRAS 21.51y 2026 Oct. 29
66P/du Toit 14.78y 2033-Apr-18
126P/IRAS 13.4y 2023-Jul-5
97P/Metcalf-Brewington 10.45y 2022-Feb-14
62P/Tsuchinshan 6.63y 2023-Dec 25 (this is special --- not beyond Saturn's orbit but it is remarkable: the first comet discovered by Chinese astronomers)

And not everyone on the list will come observable. Among them, 12P is forecast to become the brightest -- plus it is the most distant at an aphelion of 33AU even beyond Neptune -- so I cannot miss it!