Month: September 2020

Chasing darkness of Kythira

Even across the Covid pandemic in 2020, we managed to organize the second trip to chase the darkness. As usual, our summer vacation took place in Greece, this time on the island Kythira. Based on the search on the light-pollution map, I concluded that the best would be the south-west side of the island. I found Vanis house in this location and booked it. The place was fantastic. Westside is obviously optimal for observation of the sunsets – and they were magical.

After the sunset, the Milky Way showed up and it was spectacular. Measured SQM reached 21.5, which means it was one of the darkest locations I have ever been to. My primary target was the Milky Way and I managed to capture it really well. Detailed pictures are in a separate post, but here is the view south during a moonless night.

Milky Way in fron of Vanis House
Vanis House – Waxing Crescent and Milky Way

Besides the Milky Way, I also took my portable Newtonian and captured a few deep space objects. I have to say that our vacation was not just about astrophotography, but also about enjoying the Greek sun, beautiful beaches, tasting delicious food, and simply relaxing. Conclusions: I love Kythira!

View from Vanis House
Avlemonas
Kaladi beach – the most beautiful beach on the island
Kaladi beach

Milky Way on Kythira

To capture our home galaxy Milky Way properly was my dream for a very long time. A long time ago I started with Canon EOS 40D with Tokina 11-20 f2.8. Then I changed the rig to Olympus PEN-F with Zuiko 12-40 mm f2.8. A year later I upgraded to Zuiko 8 mm f1.8. Recently I purchased a second-hand full-frame camera Canon EOS 6D and I let it modified for astrophotography. All my previous attempts were based on a single photo strategy, following the 500 rule. Basically, you divide 500 by the focal length of your lens and you get maximal exposure time. Of course, you have to crank up the ISO, use as wide aperture as possible, and a tripod. Photos produced by the above-described methods lack the details or they are very noisy, depends how much you de-noise in post-processing.

However, there is another method, which requires a tracker, which is basically a motor with a gear, which makes a full revolution in one day. By other words, it compensates for the Earth’s rotation. This means, you are not limited by a single picture, but you can make as many pictures as the weather allows. Of course, you have to stack the pictures. Therefore the post-processing is a bit complicated, but the signal to noise ratio can be significantly improved. I purchased Baader Nano tracker for my trip to Fuerteventura, but I was struggling with the equipment (shutter release, polar alignment, and lens) and as soon I got familiar with the setup, the weather got really bad, so the outcome was not as expected.

I got a new opportunity to test this set up on Kythira, where the Milky Way was not spoiled by the light pollution, because in direction south, there was nothing else than the Mediterranean sea. The primary target was the Rho Ophiuchi cloud complex. I have to say that I managed to capture it really well:

LensSigma 50 mm f1.4 Art@ f2.8
CameraCanon EOS 6Da
MountBaader NanoTracker
Exposure80x25s, ISO 1600
Date2020-07-11

After collecting 80 photos of Rho Ophiuchi, I pointed the camera to the east side of the Milky Way and I tried to capture the brightest objects in the sky – Jupiter and Saturn (upper left corner). Can you see the dark cloud at the bottom left corner? This is NGC6726 Nebula and NGC 6723 Chandelier Cluster.

LensSigma 50 mm f1.4 Art@ f2.8
CameraCanon EOS 6Da
MountBaader NanoTracker
Exposure40x23s, ISO 1600
Date2020-07-11

The next day I turned the camera 90 degrees and capture the Milky Way again. At the bottom, there is “a line” of red nebulas. From left to right: Cat’s Paw Nebula, Lobster Nebula, Lagoon and Trifid Nebulae, Omega Nebula, and Eagle Nebula. The brightest object at the top right is Jupiter, making some reflections.

LensSigma 50 mm f1.4 Art@ f2.8
CameraCanon EOS 6Da
MountBaader NanoTracker
Exposure47x25s, ISO 1600
Date2020-07-12

Here is another stack of 40 pictures targeting the core of the Milky Way.

LensSigma 50 mm f1.4 Art@ f2.8
CameraCanon EOS 6Da
MountBaader NanoTracker
Exposure40x25s, ISO 1600
Date2020-07-12

Later on, the Milky Way started to submerge into the Mediterranean Sea, so I changed the composition slightly, to capture the constellation Scutum. I also changed the post-processing technique and left bit of the green color. 

LensSigma 50 mm f1.4 Art@ f2.8
CameraCanon EOS 6Da
MountBaader NanoTracker
Exposure47x25s, ISO 1600
Date2020-07-12

I also took a different lens with me – Samyang 24 mm f1.4. This lens is theoretically very fast, but I experienced very ugly stars if it’s fully opened. The reasonable aperture starts at f2.4, but at f2.8 the sharpness is very good, except in one corner. Here is a stack of 55 pictures, 60 second each:

LensSamyang 24 mm f1.4 @ f2.8
CameraCanon EOS 6Da
MountBaader NanoTracker
Exposure55x60s, ISO 1600
Date2020-07-17

Or here is another wide-angle picture, which is a stack of 60 samples, each 24 second long:

LensSamyang 24 mm f1.4 @ f2.8
CameraCanon EOS 6Da
MountBaader NanoTracker
Exposure60x24s, ISO 1600
Date2020-07-13

The last picture I would like to post here is made by the smartphone Xiaomi Mi 10 Pro. The camera has a night mode, but for astrophotography, one would need something better. Google Pixels has a special feature for it. Moreover one can install a non-official port of the Goggle Camera App to third-party Android phones. So I purchased the holder for the phone, placed on a tripod, and pressed the shutter button. The camera collected photons for 3 minutes and made multiple shots and stacked them automatically. The result is, however, not impressive and I have to conclude that smartphones cannot replace the DSLR or mirrorless cameras. There is Milky Way visible in the picture, but it lacks details and stars are elongated. The conclusion: for my next expedition I still cannot leave the camera at home and take only the smartphone.


NGC 253 Sculptor Galaxy

Every time when I chase the darkness in southern lands, I try to capture some deep space objects in the southern hemisphere, which are not visible from Central Europe. One of these objects is the Sculptor Galaxy, which can be found, surprisingly, in the constellation Sculptor (south from Aquarius). Here are some features: it is approximately 11 light-years away from us, it has roughly 90 000 light-years in diameter (similar to Milky Way) and it is characteristic by the intense star formation. This galaxy is sometimes called Silver Coin or Silver Dollar Galaxy, but I pushed the colors into the yellow spectra, therefore it looks like a gold coin.

TelescopeNewton 150/600 mm
Aperture150 mm
Focal length570 mm
MountRainbow Astro RST 135
AutoguidingZWO 174MM, Guidescope 30 mm
CameraZWO 071 Pro @-0°C
CorrectorTS MaxField
FiltersNo
Exposure127x180s, Gain 94, bin 1x1,
Date2020-09-21

NGC 6559 Nebula

If we look in the middle of the night during the summer months (on the northern hemisphere) into the Milky Way’s core, we can find many prominent deep space objects, like Lagoon, Omega, Eagle, or Trifid nebulae. However, there are also not so well known, but also very beautiful, objects. For instance emission nebula NGC 6559, which can be located in constellation Sagittarius. The star-forming region is surrounded by the dark nebula B 91 in the shape of a heart. At the bottom left corner, a part of the Lagoon Nebula is visible.

TelescopeNewton 150/600 mm
Aperture150 mm
Focal length570 mm
MountRainbow Astro RST 135
AutoguidingZWO 174MM, Guidescope 30 mm
CameraZWO 071 Pro @-0°C
CorrectorTS MaxField
FiltersNo
Exposure54x180s, Gain 94, bin 1x1,
Date2020-09-21

NGC 6726 Nebula

NGC 6726 is a reflection nebula located in the constellation Corona Australis. Visually, there is a deep space neighbor, the Chandelier globular cluster NGC 6723. These deep space objects can be also found on my wide-angle picture of the Milky Way in the left bottom corner.

TelescopeNewton 150/600 mm
Aperture150 mm
Focal length570 mm
MountRainbow Astro RST 135
AutoguidingZWO 174MM, Guidescope 30 mm
CameraZWO 071 Pro @-0°C
CorrectorTS MaxField
FiltersNo
Exposure44x180s, Gain 94, bin 1x1,
Date2020-09-13

M22 Great Sagittarius Cluster

Messier 22, sometimes called Great Sagittarius Cluster is a globular cluster, visually located very close to the galactic core of the Milky Way. If we look in this direction by a telescope, the surrounding of this cluster is filled with many stars. The cluster itself contains approximately 100 000 stars and it has roughly 97 light-years in diameter. The region of the sky where is this cluster located is poorly visible from my home, therefore every time I travel south with my portable telescope, I capture some deep space objects in this region. This picture was taken under the dark skies of Kythira.

TelescopeNewton 150/600 mm
Aperture150 mm
Focal length570 mm
MountRainbow Astro RST 135
AutoguidingZWO 174MM, Guidescope 30 mm
CameraZWO 071 Pro @-0°C
CorrectorTS MaxField
FiltersNo
Exposure59x180s, Gain 94, bin 1x1,
Date2020-09-12

IC 1318 Sadr Region

Sadr Region, sometimes called The Gamma Cygni Nebula is a giant cloud of ionized hydrogen, located in the constellation Cygnus (Swan). The picture shows only a part of the whole complex. In order to capture the whole nebula, I would need a telescope with a much shorter focal length of the much bigger sensor of the camera. This is actually my second attempt. The first one from Milos Island was quite nice, but this time I dedicated a significantly longer time for this deep space object. Specifically, the picture is an integration of 405 minutes, which means nearly 7 hours in total.

TelescopeNewton 150/600 mm
Aperture150 mm
Focal length570 mm
MountRainbow Astro RST 135
AutoguidingZWO 174MM, Guidescope 30 mm
CameraZWO 071 Pro @-0°C
CorrectorTS MaxField
FiltersNo
Exposure135x180s, Gain 94, bin 1x1,
Date2020-09-11