Wesley's Tool-Box

Jupiter and Saturn appeared closest to each other in nearly 400 years on the Winter Solstice of 2020. For this Great Conjunction, the two planets were only about 6 arc seconds apart, which meant that I was easily able to take a photo of both in a single frame as you can see here. Some had expected that they might appear as a single dot, but it turned out that Saturn was discernible as a fainter "bump" on the top right side of Jupiter to the naked eyes.

To show the planets and the satellites together, I used varied exposures and then combined the results into a single photo. Titan was the dimmest that I could photograph, and it appears very faintly to the right of Saturn. Interestingly, a star named HIP 99314 was also caught in action between Io and Europa, which means that this conjunction was actually a triple affair.

By the way, I was worried that I wouldn't be able to see the phenomenon in person because it was pretty cloudy throughout the day. Luckily, most of them went away as the Sun set and I was able to take the photos for about an hour until the low-hanging clouds started to block the view. The next closest conjunction happens 60 years later and I'm not sure if I'd be around to see that, so I was glad that the weather decided to cooperate in the last minute.

Device: Nikon P1000
Settings: 3000mm - f/8
- Jupiter: 24 photos, ISO 200, 1/30s
- Saturn: 13 photos, ISO 400, 1/30s
- Satellites: 17 photos, ISO 800, 1/5s
Filters: None
Time: 2020-12-21 18:20-18:40 KST
Location: Naju, Korea
Photos processed with PIPP 2.5.9, RegiStax 6.1.0.8 and Pixelmator Pro 2.0

Jupiter and its four major satellites (Galilean moons) are good targets for time lapse photography because of the relatively rapid movement. The rotational period of the planet is slightly less than 10 hours, and Io, the innermost of the Galilean moons, orbits the planet in about 42.5 hours. Under good conditions, these things become noticeable over a span of just about an hour.

Shortly after midnight of April 20, 2018, Io came out from behind Jupiter on the left side, while the Great Red Spot was moving towards the back of the planet on the right side after being in the center. These were all captured on my camera as I took 597 photos of the Jovian system over a period of 100 minutes between midnight and 01:40AM. The photos were then stacked and processed in 1-minute intervals (6 photos on average), like the one you see above, then put together into video as you see below.


I think it shows the dynamics of these celestial objects quite well. Now that I have a good grasp of the workflow for making a planetary animation, I should be able to make a similar one for Mars when it approaches Earth close enough to be seen as half the apparent size of Jupiter next July. Before wrapping up, here's a bonus picture of the Jovian system that I took just after photographing the Sombrero Galaxy. You can actually see Io casting a tiny shadow on Jupiter. I thought I would never see that sort of thing on my telescope.


Telescope: Celestron NexStar 6SE
Device: Sony A5000 (prime focus)
Settings: (1500mm) - ISO 100 - 1/15s(#1), 1/20s(#2) - (f/10)
Filters: Baader Moon & Skyglow
Time: 2018-04-20 00:00 ~ 01:40(#1), 2018-04-19 01:03(#2) KST
Location: Naju, Korea
597(#1), 6(#2) photos processed with PIPP 2.5.6 and RegiStax 6.1.0.8

It's been about two years since I did astrophotography with my Celestron telescope. When I finally took it out of storage to take the photos of ISS recently, I noticed that the shots weren't as clear as I expected. The same problem came up as I tried to take photos of the Orion Nebula yesterday, and I realized that the collimation of the telescope was significantly off. After about an hour of fiddling, the problem was fixed and I was able to see the bands of Jupiter and the Cassini Division on Saturn again. It looks like I'm good to go for the next few months of observation, including the closest approach of Mars on July 31. Here are the photos of the two planets in the order of original (from 4K 60fps recording), stacked, and wavelet processed results. Resolution was roughly 0.32"/pixel due to the iPhone X having slightly wider lens than iPhone 6S Plus.



Telescope: Celestron NexStar 6SE + X-Cel LX 9mm eyepiece
Device: iPhone X (afocal)
Settings: 28mm - ISO 50 (Jupiter) / 250 (Saturn) - 1/60s - f/1.8
Filters: None
Date/Time: 2018-04-08 05:18 (Jupiter) / 05:30 (Saturn) KST
Location: Naju, Korea
100 (Jupiter) / 46 (Saturn) photos stacked with PIPP 2.5.6 and RegiStax 6.1.0.8

Yesterday's sky was full of light clouds that became thicker as times passed. It was just enough see very bright stars and planets, so I decided to check how large the planets would appear with my old Tamron 270mm lens on my Sony A5000 camera. Jupiter came out to be about 11 pixels wide, or about 3.3 arc seconds per pixel. I then attached the camera to the telescope and saw that the planet was about 64 pixel wide, or about 0.56 arc seconds per pixel. This is more or less in line with the 1500mm focal length.

Since Jupiter was still somewhat "photographable" even with the cloud cover, I decided to take some more photos and stacked them to produce this nice result with all four Galilean satellites in view. The last time I took a photo like this was three years ago.

Telescope: Celestron NexStar 6SE
Device: Sony A5000 (prime focus)
Settings: (1500mm) - ISO 100 - 1/2s - (f/10)
Filters: None
Time: 2016-06-10 21:48 KST
Location: Naju, Korea
20 photos stacked with PIPP 2.5.6 and RegiStax 6.1.0.8

With a nearly perfect weather returning last night, I set out to point the telescope out the window once again. This time, I installed the Baader M&S filter as I planned last week. It was an excellent time to take photos of the planets - it was not only about 42 to 44 hours away from the closest approach of Mars in 2016, but Jupiter's Great Red Spot was in view. At this approach, Mars will be at its largest apparent diameter since November 20, 2005 and it won't be surpassed until June 19, 2018. For future reference, next closest approach will happen on July 31, 2018 and that itself won't be surpassed until the one in September 2035.


I planned just for Jupiter and Mars at first, but Saturn edged into the view at the left of the window after midnight. In the end I was able to take photos of all three planets in a single session similar to what I did a year ago, except that Venus was replaced with Mars. The filter did seem to work okay, giving me a better look at the clouds of Jupiter and the dark features of Mars.

Telescope: Celestron NexStar 6SE + X-Cel LX 9mm eyepiece
Device: iPhone 6S Plus (afocal)
Filters: Baader Moon & Skyglow
Location: Naju, Korea
Stacked with PIPP 2.5.6 and RegiStax 6.1.0.8

Jupiter (200 photos): 29mm - ISO 160 - 1/25s - f/2.2 @ 2016-05-29 21:54-21:56 KST
Saturn (200 photos): 29mm - ISO 250 - 1/15s - f/2.2 @ 2016-05-30 00:16-00:17 KST
Mars #1 (150 photos): 29mm - ISO 80 - 1/30s - f/2.2 @ 2016-05-29 22:02-22:03 KST
Mars #2 (300 photos): 29mm - ISO 50 - 1/40s - f/2.2 @ 2016-05-30 00:21-00:22 KST