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Avdhoeven

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Avdhoeven last won the day on January 25 2016

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About Avdhoeven

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  1. This image shows an image of the full moon made with a DSLR camera. Using saturation tools in photoshop the colors in the image were magnified by a huge factor showing the geological structures on the lunar surface. These colors are not artificial, but actual lunar surface colors that are strengthened many times. It's nice to see for example the rays coming from Tycho and the blueish materials surrounding younger craters on the surface. Also the lava fields can be clearly distinguished by their brownish colors.
  2. IC405, aka the Flaming Star Nebula. This nebula in Auriga is lighted by the star AE Auriga. It's a huge complex of ionised gas that shines brightly in H-alpha. The shapes are almost art-like in this beautiful part of the sky. Exposures: 7x900s / 32x1200s (10.4h) Image scale: 2.2"/pixel IC405 Flaming star nebula by Andre van der Hoeven, on Flickr
  3. Davy, my son of 11, joined the astrophotographer of the year competition last year and wanted to join again this year. However, he wanted to make a deepsky recording now, so in November we went together to see if we could find a nice project that he could go on with. He went to search on the internet to see which object he wanted to photograph and came with the rosettenevel. He studied several photos and then I gave him the astroplanner software and let him determine how to put the nebula in image. Then we started in November and then together we took 3 nights of recordings of this nebula in ha, oiii and sii. The advantage of SGP is that even a child can do the work if all is well introduced SGP just runs off its program and you have a nice folder with recordings in the morning. This data I had edited myself before to see if the quality was ok, but now I wanted him to do it himself. That's why I first showed him with another recording how to process an image in APP and then combine to an RGB recording. Then how to do with PS some more color corrections to get to a final result. After that, I gave him the dataset (lights, flats, bpm and bias) and then let him go ahead. This is what came out... Sometimes as a father you can be so proud
  4. Back into the past... Because of the lack of good weather and new data it's sometimes nice to look a bit back. When browsing through my old images I thought: "What is the image in the last few years that I liked the most?" I think it was this one. It shows Barnard 344 in the constellation of Cygnus, near Sadr. This one even became an Apod in april 2015: https://apod.nasa.gov/apod/ap150422.html Especially the colours in the image and the nice contrast between the nebulae and the area without gas/dust is what I liked. I really hope that when weather permits I can take some day an image like this again, because the sky is so beautiful. Clear skies to you all!
  5. This image shows a very deep exposure of the M13 Hercules Globular Cluster. For this image data was used taken by a TEC140 and by a CFF185 telescope remotely in Spain. In the image background galaxies up to mag. 23 can be seen. Processing was done with APP with drizzling and photoshop. This resulted in a very high resolution image of this beautiful cluster. I really recommend to click through to the original image to see it in its full detail... M13 Hercules globular cluster by Andre van der Hoeven, on Flickr Exposures: CFF185/SBIG-STL11000 Lum: 19x180s + 17x600s TEC140/QSI583ws Lum: 19x300s + 10x600s RGB: 3 x 12x300s
  6. The Rosetta nebula is a very nice winter object to observe when the nights lengthen here in the Northern Hemisphere. This image was taken, in cooperation with my oldest son (he did the choice of the object and the composition of the image) and helped with imaging the data. Taken with my TMB-92 with a QSI583ws with astrodon narrowband filters. Ha: 19x900s OIII: 25x900s SII: 21x900s Total: 16,3 hours
  7. There was still some improvement possible
  8. My son got the third place in the young category of the competition. I was a very proud dad!
  9. I've made a higher resolution and reprocessed version of the SNR. If you open the link you will clearly see some more detail G65.3+5.7 Ha_OIII- bicolor by Andre van der Hoeven, on Flickr
  10. Thanks everybody for the very nice replies! I always like to image something not so common
  11. I made a huge image of a nice SNR in Cygnus which is rarely imaged, but only the last frame of the mosaic was made in October, the rest was this summer, so unfortunately I can't submit it
  12. Here is the result of my large summer-2018 project. I have been imaging this region for about 13 nights altogether between July and October 2018. You can call me crazy, using so many nights for just one object, in a region where clear nights are rare But I really wanted to see if I could catch this beautiful Supernova remnant, and I'm glad it succeeded Supernova remnants (SNR) are formed when a large star ends its life in a supernova explosion. About 300 of these remnants are currently known in our galaxy. One of the most famous remnants, the Veil Nebula, is located in the constellation of Cygnus. Although this is the most famous one in this constellation, it’s not the only SNR. Cygnus contains several obscure SNR’s, among which SNR 65.3+5.7 (also known as SNR 65.2+5.7). SNR G65.3+5.7 was discovered by Gull et al. (1977) during an OIII survey of the Milky Way. Some parts of this SNR were already catalogued by Stewart Sharpless in his SH2 catalog as SH2-91, SH2-94 and SH2-96, but they were not recognized as being part of a bigger structure at that time. The idea that they could be part of a larger SNR was postulated by Sidney van den Bergh in 1960, but it took until 1977 for this to be confirmed. This is one of the larger SNR in the sky spanning a region of roughly 4.0x3.3 degrees. Mavromatakis et al. (2002) determined the age of the SNR to be 20.000-25.000 years and the distance about 2.600 – 3.200 lightyears. The shell has a diameter of roughly 230 lightyears! This SNR is a predominantly OIII shell with also some H-alpha signal. This supernova shell is quite weak and there are hardly any high-resolution images of this region. In the internet maybe 5-10 deep images of this shell can be found and, in most cases, they don’t cover the entire shell or the resolution is quite low because it was done by using photo lenses at short focal lengths. That’s why I decided to see if I could try to image the entire shell using my equipment, a TMB92 refractor in combination with a QSI583ws ccd camera. Because of its large size I needed to make a 3x3 mosaic to cover the whole region. As so many nights were already necessary to cover the region in OIII I didn’t succeed in grabbing the H-alpha data, but on the internet I found the MDWsurvey (mdwskysurvey.org) initiated by David Mittelman (†), Dennis di Cicco, and Sean Walker (MDW). This is a marvelous project with the goal to image the entire northern sky in H-alpha at a resolution of 3.17”/pixel. I contacted them and told them of my effort to grab imagery of this SNR and they were very kind to provide me with the H-alpha imagery of this region, so that the entire SNR could be brought into view in reasonable high resolution. This bicolor image shows a combination of about 53h of OIII data (made by myself) and 20 hours of Ha-data (made by the MDW survey) in a single image. In this way the full span of the shell can be seen in all its glory. Image info: H-alpha (astrodon 3nm, mdwskysurvey.org Telescope: Astro-physics AP130mm starfire Camera: Fli Proline 16803 5 frames of 12x1200s each OIII (astrodon 3nm): Telescope: TMB92SS Camera: QSI583ws 9 frames, 158 x 1200s total G65.3+5.7 Ha_OIII- bicolor by Andre van der Hoeven, on Flickr
  13. Supernova remnants (SNR) are formed when a large star ends its life in a supernova explosion. About 300 of these remnants are currently known in our galaxy. One of the most famous remnants, the Veil Nebula, is located in the constellation of Cygnus. Although this is the most famous one in this constellation, it’s not the only SNR. Cygnus contains several obscure SNR’s, among which SNR 65.3+5.7 (also known as SNR 65.2+5.7). SNR G65.3+5.7 was discovered by Gull et al. (1977) during an OIII survey of the Milky Way. Some parts of this SNR were already catalogued by Stewart Sharpless in his SH2 catalog as SH2-91, SH2-94 and SH2-96, but they were not recognized as being part of a bigger structure at that time. The idea that they could be part of a larger SNR was postulated by Sidney van den Bergh in 1960, but it took until 1977 for this to be confirmed. This is one of the larger SNR in the sky spanning a region of roughly 4.0x3.3 degrees. Mavromatakis et al. (2002) determined the age of the SNR to be 20.000-25.000 years and the distance about 2.600 – 3.200 lightyears. The shell has a diameter of roughly 230 lightyears! This SNR is a predominantly OIII shell with also some H-alpha signal. This supernova shell is quite weak and there are hardly any high-resolution images of this region. In the internet maybe 5-10 deep images of this shell can be found and, in most cases, they don’t cover the entire shell or the resolution is quite low because it was done by using photo lenses at short focal lengths. That’s why I decided to see if I could try to image the entire shell using my equipment, a TMB92 refractor in combination with a QSI583ws ccd camera. Because of its large size I needed to make a 3x3 mosaic to cover the whole region. During the summer of 2018 there was a prolonged period of clear nights and I decided to spend 1 night per frame to try to grab the faint OIII emission of the shell and later maybe the H-alpha data to combine these. Because of some nights with faint cloud layers I needed about 12 nights to gather the data, where 1 frame (top right corner) could not be finished in time during this season. This will be on the list for next year. Fortunately, this region almost doesn’t have any OIII emission, so it could be left out for the moment. As so many nights were already necessary to cover the region in OIII I didn’t succeed in grabbing the H-alpha data, but on the internet I found the MDWsurvey (mdwskysurvey.org) initiated by David Mittelman (†), Dennis di Cicco, and Sean Walker (MDW). This is a marvelous project with the goal to image the entire northern sky in H-alpha at a resolution of 3.17”/pixel. I contacted them and told them of my effort to grab imagery of this SNR and they were very kind to provide me with the H-alpha imagery of this region, so that the entire SNR could be brought into view in reasonable high resolution. To make the entire shell visible it is necessary to combine H-a and OIII imagery as these are complementary datasets that fill each other’s gaps. Regions where there is no H-a data are filled with OIII signal and also the other way around. The inverted image and the monochrome image show a combination of about 43h of OIII data (made by myself) and 20 hours of Ha-data (made by the MDW survey) in a single image. In this way the full span of the shell can be seen in all its glory. The inverted image highlights the faint structures which are more easy to discern to the human eye in this way of projection. The final plan is to create a bicolor image of this region in time, but because of some problems of the OIII frames in the right part of the image, and the missing top corner, that will be done probably next year. To give an idea of what can be obtained the image shows one of the frames in H-a/OIII bicolor. In the first years after its discovery several papers were published about this SNR. But as soon as radio, optical and X-ray observations were done the remnant was abandoned by most researchers and no attention was given to it. In 2004 a new study was published by Shelton, Kuntz and Petre which showed this SNR to be the oldest known remnant of a so-called Thermal Composite SNR (or mixed-morphology SNR). After a supernova has occurred the remnant will go through four phases: - Free expansion (<300 years) - Adiabatic or ‘Taylor-Sedov’ phase (around 20.000 years) - Radiative or snow-plow phase (up to 500.000 years) - Merger with the interstellar medium The free expansion phase is independent of the kind of supernova explosion. During this period all materials are accelerated outward and the evolution during this phase only depends on the amount of energy released during the explosion. Velocities of the expanding shell can be up to 104km/s. During the adiabatic phase the shell continuous its expansion, but starts to decelerate because of the presence of the interstellar medium. During this phase the energy is conserved and the temperature increases towards the center of the expanding shell, while the pressure in the center approaches a zero value. During the radiative phase the energy of the shock is dissipated by the interstellar medium and the remnant becomes a very thin, dense shell of material which cools rapidly. The interior of the remnant can remain hot. During the cooling the materials will cool down below the recombination temperature of the atoms and the materials will dissipate into the interstellar medium. In a thermal composite SNR the SNR has reached the radiative phase but still has a significant x-ray emission from the inner part of the shell caused by thermal radiation. One of the theories is that this happens to supernovae that take place in large molecular clouds where the expanding shell collides with the surrounding materials. The article of Boumis et al. (2004) shows that the SNR has a barrel-shape which expands with an average velocity of 155 km/s which is not enough to explain the x-ray emission of the nebula. It is thought of that the supernova took place in a cavity that was created by a progenitor explosion. It could be that the shockwave of the second explosion passed the shockwave of the first explosion and as such gives rise to a merger of the two shells. Image info: H-alpha (astrodon 3nm, mdwskysurvey.org Telescope: Astro-physics AP130mm starfire Camera: Fli Proline 16803 5 frames of 12x1200s each OIII (astrodon 3nm): Telescope: TMB92SS Camera: QSI583ws 9 frames, 123 x 1200s total I would also like to propose to call this nebula the 'cars-nebula'. The image shows why
  14. Thanks for all the replies! I wrote a tutorial how to use internet databases to find all the galaxies and how to mark them: http://www.astro-photo.nl/tutorials/detecting-and-marking-faint-galaxies-in-pixinsight
  15. This image shows a very deep exposure of the M13 Hercules Globular Cluster. For this image data was used taken by a TEC140 and by a CFF185 telescope remotely in Spain. In the image background galaxies up to mag. 23 can be seen (see inverted image). In total about 160 background galaxies can be found. Exposures: CFF185/SBIG-STL11000 Lum: 19x180s + 17x600s TEC140/QSI583ws Lum: 19x300s + 10x600s RGB: 3 x 12x300s M13 Hercules Globular Cluster by Andre van der Hoeven, on Flickr M13 Globular cluster background galaxies by Andre van der Hoeven, on Flickr
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