This weekend weather in London was quite amazing: sunny, a bit too windy, but sky almost perfect. Seeing forecast was also encouraging, so on Friday evening I took a chance to shoot at Jupiter.
It was a bit of an unlucky evening: firstly I discovered that I forgot my red dot finder on, so the battery was totally drained. After struggling for a while trying to align my GoTo mount without it, I decided it was worth to leave the telescope alone for a few minutes (my garden is easly visible from the street... I didn't want to do it unless absolutely necessary) and got back inside to find new batteries.
After everything was aligned, and I was ready to observe and record my images, I noticed that the image wasn't exactly satisfying at the eyepiece. When I replaced the eyepiece with the camera, the very unfocused image revealed me why: some tree branches were in the way, and of course the image was deteriorated from the interference!
I looked around me to see if I could find a better spot to place my scope, but with no luck. I decided to try anyway, taking multiple shots, so maybe in some of them I might get an almost clear picture.
This is the best result I could get:
Of course, the difference with my previous shots taken with a bigger 200mm SC is pretty visible, but I think with better conditions this new telescope can do much more.
Since I made four sets of images, spanning a bit more than 40 minutes, I was also able to an animation showing Jupiter rotation:
- Celestron Nexstar SLT 127 Maksutov
- ZWO ASI 178mm with LRGB filters
- Software: my Planetary Imager for shooting, Autostakkert!2, Registax, Siril and GIMP for image processing.
Luminance channel: 4500 frames, best 20% used. R/G/B channels: 1000 frames, best 40% used.
I'm currently living in a house with a very nice backyard, right outside London. Still a lot of light pollution, but it can be manageable, and useful for testing my equipment before running to darker locations.
This was meant to be a (L)RGB shot, but light pollution and humidity made the blue and green channels pretty useless, while red channel produced quite good results
Last friday night the sky was finally very clear, so I made a few shots.
The brilliant Orion Nebula (M42) is very well defined, but also the Flame nebula (NGC 2024) is quite conspicuous on the left. And very close to the Flame nebula, a tiny Horsehead nebula can be spotted too.
For being just a test shot, I must say I'm very happy with the result, and can't wait for better conditions to try RGB.
I recently bought a new smartphone, a OnePlus 3, since my Nexus 6 was pretty much dead, turning off pretty much everytime I did something else than keeping it in my pocket.
I was particularly interested in the "manual controls" feature of the OnePlus, including the ability to shoot up to 30 seconds, particularly convenient if you want to use it for astronomy.
It turned out this really works out well!
I just did a few tests, but the results are very promising.
The phone can also save images in RAW format, which means that if I'll also be able to program a sequence of shots, I could be able to stack pictures, to produce even better results.
It's been a while since my last updates. I recently moved to London, changed work, and.. changed astronomical instruments too. I'm planning to buy an ultra portable 300mm dobsonian soon, probably the best choice since I would like to travel as much as possible with it - back to Italy, or maybe to the southern skies.
But I also wanted a "quick" telescope, lightweight and simple, something that I could bring out in the garden in a very few minutes, and even better, ready for planetary imaging, so in the meantime I also bought a small Maksutov-Cassegrain telescope, a Celestron Nexstar SLT 127. I also got a new camera, USB3, with very high resolution and wider field than my previous one, a ZWO ASI 178mm, still a monochrome camera, but this time with RGB filter set.
Given the smaller aperture, I'm not expecting really great shots, but my previous setup much heavier, so I spent very little time observing and shooting, which in turn means I didn't really got it to its maximum potential.
My first shooting with the new setup is a very difficult one: Saturn, in an unfavourable time, quite far away from its opposition, and very low in the UK skies.
Given the small aperture, and the difficult target, I can say I'm really satisfied about it. I also tried a few new softwares for image processing, particularly ImPPG, with a very handy lucy-richardson deconvolution filter, which greatly improved the image over my first processing attempt.
A very convenient tecnique in c++ programming is the one known with many names: "d-pointer" (found in Qt/KDE contexts), shadow pointer, "pimpl", opaque pointer. Basically the idea is to hide all the private details of a class in a forward declared private pointer, which will be the only real private member of the class. Since this member will never change, this will guarantee binary compatibility among different versions of a library.
But there are other advantages in using d-pointers: one is compilation speedup during development (usually if you change a private member of a class, the header changes, and you have to recomplile all units using that header, while with d-pointer you change only the .cpp file), and another is code cleanup: you will have very compact header files, describing your class public interface without private stuff pollution. Also, sometimes you may want to add your d-pointer definition in a separate header file, ending up with three well defined files:
- myclass.h: class declaration, only public stuff, without private stuff
- myclass_p.hpp: private class declaration: only private stuff, no implementations
- myclass.cpp: only implementations
The classical approach is to create a plain raw pointer to a forward declared class, initialize it in the constructor, and delete it on the destructor. A nice addition is to have the private class be a nested type, so that you can avoid polluting your IDE class list.
It has happened in a few occasions, to launch a command in a shell only after a command in another shell has successfully finished (for instance, after a long task like source code compilation, i want to launch tests on another shell).
This sunspot was particularly big, so I waited for the best moment to try and catch it.
Seeing wasn’t great, and my solar filter was a bit damaged, but the final image doesn’t look too bad anyway.
Unfortunately, this will be the last image for a while.
Just a few hours later, someone opened my car, and took away my HEQ5 mount, together with all my eyepieces and the camera I used for all my planetary shots.
I’ll also be relocating in a while, so I’ll wait a few months before buying a new setup.
If someone is interested, I’m selling my current main optical tube here: http://www.astrosell.it/annuncio.php?Id=70007
This was meant to be an improvement to the previous ISS shooting, since I tried to do it with a bigger telescope, but the low altitude and the very bad seeing did actually worsen the quality.
The shape of the Space Station is anyway clearly visible, as it passes in front of the Moon. It is dark, this time, because it already entered in Earth shadow. We could actually see it rising, bright as usual, and then slowly fade until it completely disappeared just a few seconds before crossing the Moon.
Technical details of the shot can be found on the pagina Youtube.
Mars is getting really close to 2016 opposition, the best in the last 10 years, since it’s very close to earth.
Weather in Milan wasn’t great these days, so me and Alessia tried to catch the first night offering a clear sky and a possibly good seeing.
We were pretty much lucky: seeing wasn’t the top, with mars being very low on the horizon, but it was good enough to get a proper look: we were able to distinguish a few major features, particularly when it began to rise a little bit over 20°.
I also took a few pictures, this is the best result, shown here with a Stellarium simulation for that day and hour.
We observed also Saturn, getting close to its own opposition too, although even lower in the horizon than Mars, and Jupiter, still quite high and bright in the sky.
At the eyepiece, it was impressive: the great read spot was particularly evident, and a satellite (we later identified it being Europa) was getting closer and closer to the planet disk.
When I started shooting with my camera it was already over Jupiter, and it’s visible as the bright spot in the left part of the planet.
Although the images are not as good as I was hoping, it was a very nice evening, we could finally have a good couple of hours doing astronomy, and it was a relief after a long time being unable to observe due to bad weather.
Last august I had the chance to see the International Space Station passing in front of the moon right from my home.
The ISS is clearly visible many nights, and depending on the user position on Earth, it might align with some object in the sky.
These days I was reorganizing my gallery, and I found the original video.
So, after reprocessing it a while, I decided to republish it.
The ISS is really fast: the video is slightly slowed down. I remember that during the transit I couldn’t see the station, and I waited a few minutes because I couldn’t know if the transit already happened or not: it was still daylight, and in the original frames is barely visible.
Only after watching the video I could finally notice that tiny dot passing right in front of the moon.
For this shot, I used my old Celestron Astromaster 130, in an alt-azimuth mount, and my QHY5L-IIm as shooting camera. I had to try following manually the moon, since I obviously had no motorized tracking.
I had to use the 130mm scope instead of my main 8″ scope because of the shorter focal length: this way I could shoot almost the whole moon, so I could be sure that I didn’t miss the ISS.