jimao22

Three days later, I filmed another eruption on same active region, AR 13078. This one wasn't so powerful (only class C4.5). The film with this one is down bellow, with a graph showing what this class mean in terms of power. The Y axis is logarithmic, so don't be fooled by the small differences.

I found that the eruption showed above was a M5 class eruption, with CME (coronal mass ejection). The fact the active region it was almost on the solar meridian, make possible interaction with Earth magnetosphere.

2 days ago I made some images to Sun, trough a Baader Ha filter. It was a batch of 99 images, a little bit of 1 minute between them (started at 9:30 and finish at 11:36). I made a film from the images and the result is in the link down bellow.

Just to understand the issue: The mount is an old ZEISS mount, a huge one, made in 1956. The 3 scopes on it have perhaps more than 70 kg, even more. The exposures are short enough to not be influenced by the poor tracking, but we need to take bunch of them, with some delay between, 60...120 sec. So when you look at the series of shots, you can easily see how Sun is moving. We can align them, but the FOV is very narrow, almost same size as the full disk of the Sun, so sometime the Sun go outside the FOV. Exposures are taken with MaximDL on one computer and KStar on other. That's why I need a mean to keep all under control.

Hi there! I have a question for who can help on this. I make some solar observations full disk, but the mount is not very accurate (perhaps in the near future we'll change this). But mean while, we are using what we have. Is it possible to make guiding on Sun similar with what we are doing for stars? Or is any other possibility to do that? What crossed my mind it was to use a low F guider with a focal reducer (to try make the Sun as small as possible), with appropriate filters in the front of the guider and use PHD whith some settings that can allow some guidance. I just ask, I did not tried anything until now. Thanks in advance! Cristian

Hi, This is Iris nebula (NGC 7023 from Cepheus) trough my set-u for astrophotography: MN190 (mak-newt) on EQ6 belt-drive, ASI ZWO 533MC as main camera and QHY5II-L mono as guiding camera (OAG). The result is a stack of 41 exposures, 5 min each, from a Bortle 5 zone. Is amazing how CMOS camera and especially this one can work on a light polluted sky in full broadband. Acquisition, calibration with dark, flat and bias, debayering and stack - MaximDL, background neutralization, Photometric Color Calibration, ABE, SCNR, MMT, Histogram Transformation - in Pixinsight, Contrast, star reduction with 2 pixels and a bit of extra-denoise - in StarTools.

After a while doing my best to have a very "perfect" set-up, highly automated, I find that doing pictures in the old way fashion is not bad at all. Moreover, you can take you light set-up with you and find dark locations or find places where transient phenomena occur (like ISS transit over Sun or Moon, sun eclipses or so) so to have such a set-up is not a bad idea at all. Having this in my mind, I prepared a set-up for this purpose. It is composed mainly from a iOptron Skyguider Pro and an Omegon 66/400 apo refractor. This set-up is in continuous improvement and seems to be a great idea. Anyway, first shots look great and this is one of them. Is about M42 (Orion nebula), 32 x 60 sec + 50 x 10 sec + 100 x 1 sec, processed in HDR using MaximDL for stack and calibration and PixInsight for HDR processing. No filters at all, only light frames - camera used is ATIK 460EX at -20 deg.

Hi, This is the second target with my new color camera from ZWO. I have another shot to this target, from few years ago, but that one was a mono image, so I went back to it to see how it look like in colors. The rig used is my set-up from observatory - EQ6 belt-drive, MN190, OAG, automation with SELETEK and so on. The result is a stack of 32 x 300 sec images.

Hi! This is my first image made with my new ASI ZWO 533MC camera. The target was M81 and the picture is a result of 50 shots x 300 sec, -20 deg. C, with my MN190 Maksutov-Newtonian astrograph on EQ6 belt-drive, from my backyard observatory. The sky is Bortle 5 on my location. The workflow for processing was the following: calibration with dark, bias and flats in MaximDL, debayering in Maxim again, alignment and stack in Maxim one more time and the rest of operations - MaximDL and StarTools.

Hi. On 15-th of December I made some exposures to this lovely comet, very visible and very fast on the sky. So I took exposures 60 sec long with a pause between shots of 120 sec. The film is on the link, down bellow.

These days I was at some star-party into the mountains and I finally made the tests with the ATIK 460EX. The field is the bigger I can obtain with what I have and due to this fact, I made some exposures to Amdromeda and Pleiades. Andromeda is 27x60s+30*x20s+30x5s. M45 is 47x60s. All procesed in PI without calibration, no filters at all and a Moon at 35%.

Finally I had some decent weather and I made some exposures with my new rig: the home-made mount, the Omegon 66/400 and the ASI 174 camera. All images have the roundness less than 0.1 (measured in MaximDL) and I found that is no need for long exposures to have very good results. The final result is a balance between the shortest exposure you can do it with a good enough SNR (1) and the longest exposure you can afford with a good roundness (2). (1) depends on the local light polution, the contrast between the deep-sky object and the sky background (2) depends on the mount accuracy On my site I found that I need exposures between 30 and 60 sec for the best results with this set-up. Next tests - with the ATIK 460EX CCD camera. Much bigger... M92 - 9 x 40sec M101 - 20 x 60sec M51 102 x 40 sec M51 - detail

Due to the very bad weather this spring time, it was very hard to find a good night for testing properly the new mount. But somehow I find a proper night being with one of my astro buddies in my observatory. I made a lot of exposures with Sharpcap but the darks and flats made with MaximDL didn't work to calibrate these images. I suppose is some kind of incompatibility in acquiring the data. Even if I tried to make new darks and flats few day later using the same Sharpcap, I didn't obtain better results. The best results I obtained when acquisitions were made with MaximDL - lights / darks / flats and biases. But I had only 5 exposures like this, 90 sec each (lights). The result is great in my opinion, roundness of the stars is 0.084 and I am sure I can increase the exposure time somewhere between 2 and 3 minutes without problems - unguided subs with same great figures. The most important thing to obtain these results is the proper polar alignment. I think a PoleMaster it will be the best improvement ever for this nice mount I have.

You cannot see it because is on the back side of the mount, where the motor is. Is not rocket science, is just a screw that make a lever to push the motor axis on the sector. Is not big deal.

The friction drive can be adjusted with a screw. You cannot preload by pushing the shaft other than using some kind of lever operated by a screw. So is adjustable.

An update to this project. After few runs for testing the pros and cons for this mount, I made some technical adjustments. 1. I had some problems to polar align the mount, due to the fact the polar scope was not illuminated. So I bought a device for this purpose, a part of the modular system of Star Adventurer mount. Problem solved. 2. I had problems to obtain a good focus for the stars. So I made a Bahtinov mask who fit perfect to my Omegon 66 telescope. The Bahtinov mask is a wired one - a mask with some good advantages over a regular one due to the fact an increased quantity of light is getting inside the camera sensor. As a result, you can focus with very short exposures (1), or on dim stars (2) or with narrowband filters (3). 3. I made a huge mistake thinking that the finder is installed on the right position on the horizontal bar (see the pictures from previous posts). The finder is aligned with the main telescope only on RA, but not on DEC. So, to resolve this problem I put a shoe on the main scope and use a lighter finder scope - in this case a green laser or a red dot finder. 4. I encountered some problems when went on the field at night and tried to power the mount from my car battery. The battery had around 13 V when the mount wasn't working but the voltage droped down to 10 V when mount worked. As a result, the mount was blocked after few seconds. So I made a 12 V voltage stabilizer. This device is inserted between the power supply and the control module of the mount and the tension never drop under 11 V no matter what. So now the mount is working in the field too. To be continued with pictures of deep sky objects... When weather will allow.

Hi, As you can see in the pictures with the star shape analysis, the mount is working great, so the concept is very good. Moreover, I am sure the results will be better than usual commercial mounts same class because the friction drive is very stiff an robust and allow greater weights to be worn. The bearing is a radial SKF one and is mounted with a press, like the ones used in the car maintenance. And the machining was very precise being done on a CNC machine wit a high accuracy.

A friend suggested using the tracking speeds used by ASCOM, so that I can no longer compute them (I only started calculating them and it was a beautiful exercise of theoretical astronomy). So I used the "Sidereal tracking rate" = 15.041 arcseconds / second and "Lunar tracking rate" = 14,685 arcseconds / second ( https://ascom-standards.org/Help/Platform/...eRates.htm). After two attempts to reduce the errors to lower values, the third one came out perfectly (or almost) so that the 35 degree circle sector of the mount was moved by the engine in 2 hours and 19 minutes vs. 2 hours, 19 minutes and 37.2 seconds as the theory was. Approximation was good enough, I said ... The last step was the star test. So, Sunday night - March 18, I pulled out the mount outside the observer, pole aligned not very accurate, and looked at a brighter star from the southwest sky that was at my fingertips (star turned out to be Procyon of the Canis Minoris). I made 30 'and 60' exposures, obviously unguided, with the ASI 174 mono camera, using FireCapture as an acquisition software. The .fits images I've uploaded to MaximDL to analyze them there. The results were more than my expectations. The roundness of the stars was between 0.162 and 0.25 (the latter eliminated by the software) for the 30 'and 0.170 and 0.252 exposures for the 60'. For unguided images, at first try, I think is amazing! I am so pleased!...

Problem with the shaft was solved by grinding it (the fastest method). The remaining problem before goes under the stars with the mount and the telescope, was to adjust the sidereal and lunar tracking speed. This was not an easy task. The first time I had to figure out what is the current speed and precisely determine the major angles of the circle sector on which the engagement is made. That's why we used a special protractor. I found that for a full bow stroke we have 50.6 degrees and the angle between the arms of the arms is 35 degrees. This was the one I used for the following calculation.

And the last updates, before getting into the sidereal and lunar speed calibration (1) and motors for auto-guiding (2). Today the second counter-weight arrived to me. Mean while I made 2 lids for the objective and the eyepiece of the polar scope. A last problem to be solved at this stage - the shaft of the tracking motor is intersecting the rod of the secondary counterweight when working. I have some options but I need to think properly before to act.

Last day I spent it on my workshop working for the changes to the mount to resolve that imbalance of the weight on RA axis. I tried to resolve this using a piece left from one of the "L" shape supports and by milling a new part from aluminium to connect this part with the mount itself. This took me a lot of time, even if the piece had a shape free of constrains. Anyway, the result was very nice and after a sandblasting treatment of the mount and the connector, I had a nice surface to be painted. The color I choose was close by the equatorial wedge (red) keeping the edge natural (aluminium color) - to have a bit of contrast. Because of the fact I have only one counter-weight at this moment, the pictures bellow will show you how the mount should look like with the only weight I have installed on both position one at a time. I will have the new pieces these days and I will be close by the final result one step further.

A last minute update - as I said, the finder will be installed on the mount. I find a way to do this with minimum of damage or changes in the components and maximum of sturdiness. Now I have to calibrate the sidereal and lunar speed by changing a variable in the ARDUINO controller program. I made some measurements on the tracking sector and the following days I will make the calculation and adjustments to this parameter to see how it works. Anyway, a new improvement is rising because is obvious I need another counter-wight to compensate the imbalance on the RA tracking motion. Tomorrow I will be in my workshop to try solve this problem. When the new counter-weight will arrive to me, I will show you what I did.

The two buttons to adjust DEC and RA independent movements.

The problem with that configuration was not so obvious at the first glance, but it was a big problem. Due to the fact the RA movement is only on a 30 degrees of an arch, I couldn't point to a huge part of the sky. For example - on the South, or to the Zenith. The RA should be changed accordingly. So my idea was to buy another "L" shape support and a counter-weight to solve this issue. This way, I "doubled" the RA movement and kept the DEC as well. Both (new RA and old DEC) movements are like a spherical joint and so I have access to all sky, without problem. Moreover, I can motorize both movements for auto-guiding independent from the tracking, which I consider is a big advantage. The pictures are bellow. I intend in few days to install a finder on the set-up to have a better field of view. This story will be continued...

So the first result looked that way... Tomorrow I will show you the continuation...