100-minute tracking of Jupiter

Jupiter and the Galilean moons seen on 00:44, April 20, 2018

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.

Jupiter and the Galilean moons seen on 01:03, April 19, 2018

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

Sombrero Galaxy

Sombrero Galaxy seen on the night between April 18 and 19, 2018 (25% size)

I was looking to photograph a galaxy that was shaped distinct enough to look like something other than a blob of fuzzy light ball under limited equipment and conditions. Looking through the available targets, I picked out the Sombrero Galaxy, also known as Messier 104. This is a spiral galaxy in the Virgo constellation that resembles the shape of a sombrero, a Mexican style wide-brimmed straw hat.

As you can see here, the observation and the photography were successful. The "brim" definitely makes the galaxy easily identifiable, helped by the use of a filter to cut down the ambient light pollution. The photo isn't quite as smooth as I liked due to the field rotation inherent in the Alt-Az mount. This prevented me from using an exposure time longer than a minute, and I had to compensate with a high ISO setting.

Telescope: Celestron NexStar 6SE
Device: Sony A5000 (prime focus)
Settings: (1500mm) - ISO 3200 - 60s - (f/10)
Filters: Baader Moon & Skyglow
Time: 2018-04-18 23:08 ~ 2018-04-19 00:48 KST
Location: Naju, Korea
7 photos stacked with DeepSkyStacker 3.3.4

A more successful tracking of ISS

ISS as seen from Naju in April 12, 2018

After several days of clear skies, clouds have been rolling in for the past two days. Amazingly, they did thin out for a few hours in the evening, enabling me to see the ISS for two consecutive days under good conditions. Tracked observation on April 11 failed due to low battery on the telescope, but I was better prepared on April 12 and made a successful tracking.

The International Space Station was 546km away from me at the closest approach at 19:38:03 (408km altitude, -3.6 mag brightness), so the second photo from the bottom right is representative of this. It is coincidentally the clearest photo I got. You can identify many of the modules - starting from the Zvezda module on the top and moving down, you can see the Zarya module in the center with two radiator panels side by side. On the bottom, you can see the cluster of Columbus-Harmony-Kibo modules in the center, with large solar panels on each end. The bright spot is likely where the SpaceX Dragon spacecraft from the CRS-14 mission is currently docked at.


As I have captured several hundreds of frames, it was sufficient enough to arrange them into this 34-second video clip. I have hosted the file on the website, and it should be watchable on a modern browser.

Telescope: Celestron NexStar 6SE + X-Cel LX 9mm eyepiece
Device: iPhone X (afocal)
Settings: 28mm - ISO 400 - 1/1500s - f/1.8
Filters: None
Date/Time: 2018-04-12 19:37-19:38 KST
Location: Naju, Korea
Photos processed with PIPP 2.5.6 and RegiStax 6.1.0.8
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Nebulas and galaxies in the spring sky

Orion Nebula (Messier 42, 25% size)

I haven't taken a look at nebulas and galaxies in several years - the last time I did so was back in November 2015. With the clear evening skies persisting for a few days, I thought that it was a good time to make a return observation. The easiest, and thus the first target was the bright Orion Nebula. I first made several attempts with my iPhone X, but it did not yield the level of quality I wanted and switched to Sony A5000 for the result above. As it was April, the nebula was heading towards the horizon in the southwestern sky and thus subject to less than dark background and drowning out darker portions.

Bode’s Galaxy (Messier 81, 38% size)

Moving to the northern sky, I took a look at something I haven't checked out since moving to Naju - the Bode's Galaxy and the Cigar Galaxy. I last saw them in May 2014 in Suwon. Due to the worsening light pollution I can't say I had better observation conditions, but I did have better equipment now. And the results speak of this advantage, as the galaxies were captured in finer detail. I especially like how the variation of brightness appears in the Cigar Galaxy below.

Cigar Galaxy (Messier 82, 38% size)


Telescope: Celestron NexStar 6SE + f/6.3 focal reducer
Device: Sony A5000 (prime focus)
Settings: (945mm) - ISO 1000(#1) / 2500(#2) / 3200(#3) - 30s - (f/6.3)
Filters: None
Time: 2018-04-09 20:23-20:38(#1) / 22:27-22:40(#2) / 22:49-23:10(#3) KST
Location: Naju, Korea
5(#1) / 10(#2) / 13(#3) photos stacked with Deep Sky Stacker 3.3.4

Getting the telescope back on its feet

Jupiter and Saturn on April 8, 2018

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.

The look of Jupiter before and after collimating the telescope


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

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