Wesley's Tool-Box

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

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.


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.



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

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

Tiangong-1, the first Chinese space station, is set to fall back to Earth around April 2. Its orbit had been slowly decaying since its service was ended in 2016. I found out that it would be visible for one last time in the sky this morning, so me and my daughter Celine decided to witness its streak. I set up my iPhone X on a tripod and placed it on the window facing north. Then I launched NightCap Camera app in satellite capturing mode.

Shortly after 5:30AM, Tiangong-1 made its bright (-0.6 magnitude, 181km altitude) appearance from the west, streaking towards east and quickly dimming. Just as it disappeared from our eyesight, another bright flash appeared to the east of Polaris and then quickly disappeared. From my experience I knew that was an Iridium flare. CalSky website verified it to be Iridium 80, showing up at 5:30:36AM with a magnitude of -2.0. We were very lucky to see the two together - since the space station will disappear in a couple of days it was truly a once-in-a-lifetime experience.

On the photo, you can see, starting from the top left and looking towards bottom right, the Tiangong-1, Polaris, Iridium 80, and the Cassiopeia constellation. Click on the image to see it in full size.

Device: iPhone X
Settings: 28mm - ISO 2112 - 61s - f/1.8
Filters: None
Date/Time: 2018-03-31 05:30:01 KST
Location: Naju, Korea

The International Space Station was to make a very close pass to Rigel, one of the brightest stars making up the Orion constellation, last Saturday evening where I live. The separation at the closest point was around 0.055°, making it look like the space station passing right over the star to the naked eye. Instead of manual tracking, I decided to fix the telescope on Rigel and record the pass with iPhone X's 4K 60fps video mode. A total of 50 consecutive frames captured the rapid movement. The windy condition, coupled with relatively low angle (35.6°) blurred the results a lot, so I should try this technique again at a higher angle.


Here's the rotated video of the pass, once at the original speed and once at the slow speed.

Telescope: Celestron NexStar 6SE + X-Cel LX 9mm eyepiece
Device: iPhone X (afocal)
Settings: 28mm - ISO 880 - 1/1500s - f/1.8
Filters: None
Date/Time: 2018-03-24 20:00:59 KST
Location: Naju, Korea