han59

After digging trough some code, I found the command line option of platesolve2 plate solver. Maybe useful for some (script) programmers: Command line: PlateSolve2.exe (Right ascension in radians),(Declination in radians),(x dimension in radians),(y dimension in radians),(Number of regions to search),(fits filename),(wait time at the end) De wait time is optional. The 6 of 7 parameters should be separated by a comma. The values should have a decimal point not a comma. Example: platesolve2.exe 4.516,0.75,0.0296,0.02268,999,1.fit,0 The plate center result [rad] RA,DEC is reported in the first line of a text file with extension .APM Han

Andrew, I would prefer if I could dim the neighbor lights rather then the power led lights. Anyhow I just covered all led's of the surveillance camera with duct tape and the ir-light level is certainly down. I still can clearly see the wall 2 meter away. I will switch on the led's on/off remotely when I'm briefly watching. It is called a night camera but it is without ir-lights it much less sensitive then the human eye Covering the clamp connection with alu foil will certainly help. I was an enlightening moment we I saw that covering the clamp connection with my hand solved the dark problem. But in any case the light level should much much lower. About flats. How do you guarantee a pin hole will spread the light equally? Anyhow I think now the best solution for flats is an EL panel. Bought an EL panel for about 15 euros. The only trick is to dim it using a resistor. I never had success using the sky an had always gradients. Secondly the camera cooling will not reach the low temperature in a warm day. Here my EL panel solution: http://www.hnsky.org/el_panel.htm p.s. are those images taken in your garden? Regards, Han

No, all mounting material is metal. The infra red light is shining trough the clamp coupling with one screw. With any clamp coupling always a fraction of a mm space will be left open. Since the internals are never 100% black painted, the light will tunnel through. The clamp coupling is of reasonable quality and has a spring ring to spread the mechanical load. I assume a fully screwed connection will be light tight. With respect to the black dust cap. In the process of fault finding, I removed the camera and put a black plastic dust cap on it for new darks. The dust cap is fully opaque for the eye but the sensitive camera still sees infra red light going through. So my initial thinking was a random faulty camera. An other problem is the manual filter wheel. You can cover it but as Wim mentioned often problems during daylight. For me also all dark are taken exclusively at night. Too many light leakage problems during daylight. The surveillance camera led's are capable of illuminating objects 10 meters away. So much too bright for my application. It assume is also possible that they illuminate the air humidity above the telescope. Since my telescope distance is 1m5 or even less, the amount of infra red light can be reduced with (10/1.5)*(10/1.5) => 50 x So one of the leds should be more then efficient to illuminate and the others can be covered. Or just leave separate small red light on. So solutions are: All screwed connections and reduce light from surveillance camera or use a weak separate light source. I guess if you have an imaging camera with fixed IR/UV blocking filter front there will be less problems. The ZWO front window is fully transparent to IR and I have the IR/UV blocking filter in the filter wheel. Han

Learning case: My last nightly deep sky imaging sessions did not give good results. Also the dark's were brighter on one side. Changing a USB3.0 cable did solve the problem temporarily. However, it came back and I was about to blame and return my 1/2 year old imaging camera. Strange enough, the effect was depending on the telescope position and ultimately I found it was caused by infrared light leakage due to the imaging camera coupling. The infrared came from the surveillance camera I use to monitor the setup. My recording camera is the very sensitive ASI1600MM-Cool. This camera is also sensitive to infrared. The IR / UV blocking filter is placed in the filter wheel. The camera coupling let enough infrared light through to disturb the imaging. The surveillance camera has been placed approximately 1m5 from the setup and has been in operation for a month. After all, trivial but you expect a coupling to be sufficiently light tight. The effect was also strongly depending on the telescope orientation. In infra red the arrangement was illuminated, although for the human eye's the surveillance camera LED's barely lighted. Due to it I lost two clear nights. In addition, I also noticed that 2 "black plastic covers are for infrared permeable, otherwise I'd have located the problem much earlier. Looks like they require additional aluminum foil cover to be light tight for the ASI1600 Han The surveillance camera: Imaging camera and point of leakage:

if made of lorry curtain material it would last very very long.

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: http://www.downunderobservatory.com/equipment.html http://www.company7.com/optec/observatory.html Han

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

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

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: http://www.hnsky.org/observatory2.htm 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:

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: http://www.hnsky.org This was a large overhaul. Please report any problem or bug. Clear skies, Han Setting menu:

The bigger (orbital) picture

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

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) : http://www.hnsky.org/software.htm M13 with Gaia: Center of M13 with Gaia: Object menu of HNSKY:

For the few interested in star catalogs: Gaia data release set for 14 September: http://sci.esa.int/gaia/58042-mark-your-calendar-gaia-data-release-set-for-14-september/

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