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About han59

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  1. if made of lorry curtain material it would last very very long.
  2. The key to success for flip top design is weight control. Reports from Adaaam75 and others warned me that weight is a major design issue. The weight of my best half is 14 kg. About 6 kg for the thin 0.35mm metal roofing, 6 kg for the wood and the remainder for screws. So even the wood thickness and screw counts. You have to do the math so the weight calculation beforehand. I also made a simple test setup from which I learned that 1) the weight forces increase multiple times if the roof half reaches the open position maybe 20 degrees above horizon. 2) You have to stand high enough to handle the half comfortable by hand. 3) Maximum weight to handle comfortable is about 15 kg for me. When standing on the "step" my shoulders are about 40 cm above the hinges. Here my simple test setup to get the feeling of the forces: Forgot to mention, As a precaution I also have made a stick of about 4 meters to be able to lock the two halves in open position for windy conditions. The halves open north/south and the main wind direction is from west so this hasn't been a problem up to now. And here links to two successful flip-top/bat-wing designs: Han
  3. After 5 weeks haven't noticed any condensation yet. If so, it could drip to the outside. Ventilation in closed position should be good. Maybe I should install styropor plates on the inside in the long run. Han
  4. This is an interesting galaxy but very faint. Total exposure time a little more then 5 hours in 2 nights. Conditions where as usual not ideal but I'm happy with the result: NGC4236 ( Caldwell 3, PGC39346) on 2017-4-18 en 19, Telescope 100 mm APO astrograph APO100Q, F5,8 Camera ASI1600MM-Cool, bin x2 94x200sec
  5. My new observatory is now one month ready. It only needs some painting. Below some pictures and a link to the building report. Maybe useful for some: The design is called bat wing or flip top. Please advice me if you have a better naming. It is located in the Netherlands. The roof of the observation can be opened manually using handles. The two halves open at the peak of the roof and are hinged to the sides of the building One halve opens to the south and allows imaging of objects lower then 20 degrees above the horizon. This clamp shell roof design is not very often used. The big advantage is that less ground space is required. To make it success the two roof halves needs to be very light. The northern half is about 15.5 kg and the southern half is 14 kg. The halves are made of 0.35mm galvanized metal roofing plates with wooden support. The southern half is made of lighter wood 20.5x48 mm . For opening the half a "step stool" of about 40 cm height is used to be able to handle the 15 kg weight comfortable. In close position they two halves are locked. The floor space is 2x2 meter (6x6 feet). The walls height is 1.725 meter from the floor and rooftop is at 2.265 meter from the floor. The telescope can freely move under the roof. The foundation is made using 4 big concrete tiles 0.4 x 0.6 x 0.05 meters which where dug in and will spread the total shed weight of 700 kg sufficient. The space under the floor is enclosed using other additional concrete titles to prevent old leaves and debris to enter. A pier of oak wood is installed mechanical isolated from the floor. The oak pier is 0.15x 0.15 x2.6 meters pole and was dug in manually and no concrete was used. The pier is 1.16 meter above shed floor level. An oak pier should survive typically 18 years in the ground and some extra bitumen coating was applied as an extra precaution. The walls are made of Douglas fir tongue and groove joint wood ordered in lengths of 4 meters. A permanent power cable is installed and extra 80 cm earth rod as an extra precaution. The required 12 volt switching power supplies do not provide 100% potential free power and all 12v minus connections and the computer housing where earthed using this extra earth connection. The HEQ5pro pier top is based on two thick steel plates, 200 x 150 x 6 mm. The two rectangle plates including the main 60 mm hole for the HEQ5 Pro where ordered at a local machine shop for Euro 43. Further drilling, machining and painting was done at home to save costs. The bottom plate is screwed with four "lag bolts" to the pier. To prevent the wood splitting, the holes for these bolts where pre-drilled and placed not to close to the sides. A wifi link allows remote control from inside the house using Windows "remote desktop" feature. To open the roof half after unlocking the first step is to step (lowered) on the step stool and to push the roof open manually. When the roof half reaches the end position the forces increase but in a high position on the step stool this is manageable. The ropes have some flexibility which is a plus. The oak pier just before digging in: Experimental stabilization fins: Foundation build on four big tiles: Roof detail: In raining conditions: Side view:
  6. Version 3.3.0, (3.3ß37 Linux) of the freeware planetarium program ,,Hallo Northern Sky" for MSWindows is released. Added support for Jet Propulsion Laboratory Development Ephemeris (like DE430, DE431). The JPL DE431 is covering years –13,200 to +17,191 and is a 2.8 gbyte download but will give highly accurate planetary positions for a very long period. It will be beneficial for planetary occultations. If you only want accuracy, download a reduced DE430 file of 5 mbytes only covering the years 2000-2050. Links are provided within the program, menu settings. See screen shot below. Secondly the planetary unit is overhauled. Added apparent position to the menu. Updated time menu and added Julian day input. Webpage: This was a large overhaul. Please report any problem or bug. Clear skies, Han Setting menu:
  7. The bigger (orbital) picture
  8. Using Gaia DR1 for star mapping has it's limitations. Not only the brightest stars are missing but at least 20% of the fainter stars. Probably not a problem for astrometric purposes but not good enough for star maps. The Gaia G magnitude is average about 0.3 magnitude brighter then the calculated visual V magnitude of Tycho-2. If you compare the amount of stars within a magnitude range this 0.3 magnitude offset will mask the missing stars. I compared a Tycho-2 database up to magnitude 8 with a Gaia database up to magnitude 10. I could not find 20% of the Tycho-2 stars within Gaia but the DSS confirmed they are real. To do this the Tycho-2 database was converted to Gaia epoch 2015 (In Gaia DR1 many stars don't have proper motion data yet) and a search area of 10 arcseconds around the position of the Tycho-2 stars was defined. For stars fainter then 8, I see visually the same phenomena of missing stars. This wil be solved in the next Gaia releases. I will stick to my Tycho-2 & UCAC4 compilation for the time being till Gaia DR2 is released in 2017. Han
  9. Planetarium program HNSKY can retrieve Gaia data from Vizier. Gaia is an astrometry catalog but using it for star mapping, the global cluster M13 looks natural. There is no black hole of missing stars in the center and the faintest stars in the center are of about magnitude 16/17. The stars have 19 digits numeric ID. Bright stars are missing. I'm working on a new standalone star database based on Gaia en Tycho-2. (==>Later, standalone Gaia database will not come. Too many stars missing in Gaia, also faint stars . Have to wait for DR2) Large parts of the Gaia catalogue can be downloaded using the TAP interface of Vizier. Note that only the G magnitude is is given. The detector for G is a little more sensitive in the red and the G mangitudes are average about 0.3 magnitude too bright. The next release DR2 will probably prrovide more data and colour information. Also the proper motion in DR1 is far from complete and will get better with each release. The Gaia interface of HNSKY works for small fields of about 1 degree only. To download the HNSKY 3.2.3b (planetarium program) : M13 with Gaia: Center of M13 with Gaia: Object menu of HNSKY:
  10. For the few interested in star catalogs: Gaia data release set for 14 September:
  11. I'm also highly surprised. Must be the binary files. I prefer something very established like ZIP since it is fully supported in MS Windows, but 25 percent is significant in webpage load. On the other hand they can always download the .EXE installer. Will do some trials. Han
  12. Glad it works. I have uploaded the full version as a ZIP but noted that a RAR format saves 25% space. It is now 85 mbytes ZIP rather then a 65 mbytes RAR. However moving to RAR will be inconvenient for many users. No longer required, but could you handle the RAR archive format? Han
  13. Just checked it, yes your correct there is no stardatabase in that zip file. Yes you could either install the hnsky_setup.exe and take the files from the installation or use the which contains all files including the star databases such as sao_hsky.dat, ppm_hnsky.dat and the tycho files. Again just put them in one directory. No installation required. Personally I keep the fits files in a subdirectory called fits Nevertheless, I will add all files to the same file this afternoon and just download this one again. That black cursor is an old problem for Vista and some graphics cards. In menu settings (ctrl-E), third tab COLORS, you can select a partly opaque cursor. Then save settings to make this permanent, That should fix it. Han
  14. Sorry for this very very later answer. Yes you could run it from a USB stick. You can unzip all files from the provide zip archive (see below) to the USB disk. Copy all the files and subdirectories . Move the supplements from the "Place the files of this folder in the folder hnsky under Documents" folder to the same directory containing the hnsky.exe file. Han
  15. Good the read that there is interest in Linux. I just release the first Linux version of the Hallo Northern sky planetarium program. See thread Linux is also new for me. It is compiled for AMD64 and the executable in this latest version is called "hnsky". Just unzip the files somewhere at your home drive. In future, I will compile more versions then just AMD64. If your are in need for a 32 bit version, send me an email or respond to above thread and I will include it. Any feedback is most welcome. Han