dan_adi

I found it in GAIA 3 database search. But it doesn't say much about it. Still don't know what object it is. But from Gaia magnitudes I was able to compute the V mag using the following formula: V = 0.0176 + 0.00686*(Gbp - Grp) + 0.1732*(Gbp - Grp)**2 + G As a result the object has a V mag of 21.836172970356973 https://irsa.ipac.caltech.edu/workspace/TMP_y0MTfC_11488/Gator/irsa/7912/tbview.html

Sure, I have a bigger crop that solves quickly with ASTAP. The object is in the lower right corner. Fairly small and faint. The bigger the crop, the harder to locate.

Sure. Here is a png

Recently I was browsing a long-ish exposure and found an object I can't seem to find much info on it online. Maybe someone has better NED or Simbad skills than me. I looks like a galaxy but it could be a planetary nebula. The object is in a corner of a larger picture I am working on for some time. I attached a cropped image with the object centered. Maybe when I add some RGB data, things will be a little clearer, as I only have luminance data. Additional info: target coords: 16 32 54.87 +65° 45 37.4 target ID: WISEA J163255.05+654538.8 exposure time: 81 hours scope: CFF 8 inch apo mount: Mesu 200 filter: Astrodon Luminance crop.tiff

Hi, I managed to update the web app. The address is the same: http://clearskies.go.ro:8501/ I added stuff I use in my regular 'astronomy' activity, besides the exposure time calculator, like: the ability to search the Simbad database for stars, retrieve basic information and compute additional stuff. For example, making 3D interactive star maps, chosing a star of interest and computing its orbit in our galaxy, or simply computing distances between stars the ability to search Simbad database for galaxies, based on coords or name. I mainly wrote this to retrieve information about major and minor galaxy axes, so I can compute the surface brightness really quick the ability to compute cosmological parameters given a redshift and most fun, create a space-time diagram of the object of interest. This was a great way for me to wrap my head around cosmology. Overall I am pretty happy on how it all turned out. Doing the math and the programming gave me a better understanding of astronomy. A wonderful part of science! PS: The default theme for the webapp is Dark Theme. I noticed that using the light theme might make some plots not display properly. To use the dark theme, go to the upper right corner, click on the 3 horizontal bars menu, go to settings->theme-> choose dark theme

With appropriate adaptors it can fit any telescope. I use an Optec Leo on a 8 inch refractor. Stable, precise, reliable focuser.

Hello, I've expanded the webbapp quite a bit since then. I've rearranged the graphical user interface a bit, and I added stuff I usually need, like: 1. Searching the Simbad database for stars, extract info and display as table 2. Constructing 3D maps of those stars and also their 2D and 3D orbits 3. Space time diagrams, so I can understand proper distances, comoving distances and light travel time, for a given redshift 3. Searching Simbad database for galaxies, extract info, compute surface brightness ... since it's not so easy to find surfaceB for galaxies Below are some pics. I haven't had the time to upload the new app to the server .... but I hope I'll find the time soon.

Regarding guiding RMS, A while ago I was working on estimating the star FWHM given my setup and user estimating seeing. I found the relevant equation on ESOs website for computing FWHM. Oddly there was kind of a big difference between the math prediction and my actual FWHM in my subs (using meteo blue seeing forecast for my region as user entered seeing value). Since I was imaging with a quality apo and a MESU mount, I didn't get where the problem was. I went ahead and ask on the forum about meteoblues accuracy, and luckily for me Vlaiv underlined and error. When it came to guiding error, I entered the RMS value in arc seconds. This was the mistake! I had to convert the RMS value to the actual value, by simply multiplying the RMS with 2 x √(2 x ln(2)), or simply RMS x 2.355. After making the correction in the software, I actually got a reasonable prediction. So let's say the RMS guiding error is 0.5". That means the converted value is 1.17 ". So if you are imaging at an image scale of 1"/pixel, an RMS of 0.5" will have a small impact on your star FWHM. So I don't think the rule should be RMS half of imaging scale, but a little bit lower to be on the safe side After this I also realized why my imaging software, Prism, reported 2 values of error when autoguiding, one was RMS and the other one was RMS*2.355. I only realized why it reported 2 values after I did the math. In practice, when my MESU confronts wind gusts and the guiding RMS goes up to 0.5 or 0.6 " RMS, I see a deterioration in FWHM, that makes sense now. Bellow is an example of FWHM estimation with my setup and a seeing of 1.5" (the best case scenario for my area). With my setup I could still improve by going lower in guiding RMS value and a little bit lower in image scale. But this will be expensive :))

I have a processing PC and a NAS. Files are stored on the NAS. I copy them to the processing PC and go from there. After everything is done, I delete the files on the processing PC. It works well because between the NAS and processing PC I have a 10 Gbit connection. So I copy/paste at 1 GB/sec transfer speed

Not sure about field curvature, but a while ago I tested some subs of mine with ASTAP and it reported moderate tilt. All I did was to disassemble my imaging train and put it back together and the tilt was gone. With time and temperature variation connections get a bit loose. So before you panic make sure your connections are reasonably tight

Given how huge the universe is, the probability of life existing only on 1 planet is very small. We have just recently (in cosmic time) started to analize atmospheres of exoplanets, and the technology will only continue to improve. We just have to wait and see what we find in our own galaxy. I have no doubt that we will find other Earths out there, is just a matter of time and technology. The more important question is, will we be able to go there?

I have/had the same concerns, but given that there are mesu mounts 10 years old and still working, I think you are safe. After 10-15 years of using it, if it fails, you can buy another brand. Or you could have 2 mesus, one for backup...

With small increase in aperture the difference will not be so big. So get the biggest scope your mount could properly handle, but from 60 mm to 90 mm there won't be an earthshatering improvement.

This is reasonable, 10 micron has more technology in it, thus more possible points of failure. I never understood why simple and efficient friction drive mounts are not the norm. They are easier to build, handle big loads, require no mechanical maintenance, and the performance is very good. In addition the cost is much lower. A 10 micron 3000 hps, with AE and 100 kg payload is around 20k euros with all the accessories. A mesu 200 fitted with AE will cost around 14k euros. To me the difference is significant, for the same level of performance.

I use an amp meter with stable readings in order to balance the mount. This way I could balance fast and pretty precise. The newer mount has clutches for disengaging but even then I would use an amp meter just to double check. I've seen higher tech mounts like 10 micron or ASA that have the same amp checking routine for good balancing. Anyway I didn't find balancing on my MK1 to be a chore. Besides the newer improvements the only thing I would add, as an option off course, is absolute encoders. The reliability of the mesu coupled with AE will give 10 micron a run for their money 😁

I guess if it is out of balance it would slip(just like a direct drive), since there are no gears, too much unbalance would overcome the friction between the roller plates. Some years ago there was a US manufacturer that made big mounts with friction drive for professional scopes, but I forgot the name Ps: https://www.dfmengineering.com/news_telescope_gearing.html

SCTs are not known as high quality products. Maybe you were just unlucky and got a bad one.

Why would you need the mount unbalanced?

Steel. No rubber, no belts, no gears.

The mount uses a sidereal technologies controller. On their website you can download the software. The latest software is on sidereal technologies forum on groups.io The mount uses friction drives, no gears, no belts. That means it is very stiff, more so than regular worm-gear mounts or direct drive mounts. It has no backlash. The periodic error is slow, easily corrected with autoguiding. Requires no maintenance. All this combined, in good seeing, produces autoguiding RMS around 0.2 ". Given the payload - performance and price, I think it is the best mount out there. The downside is seeing. Since autoguiding performance is determined by seeing, the mount will perform according to it. But this affects all mounts. The solution is absolute encoders on both RA and DEC axes and a mount model, combined with very few guiding corrections, if any. This way you will basically guide on encoders and the seeing impact on the mount will practically be null.

The Mesu can handle a lot. I have a 8 inch refractor on it with all the accessories, maybe around 50 Kg. I know for sure the counter weights are 50 kg in total. When the weather cooperates, guiding RMS is 0.2-0.3" with this load. Also, in my case at least, with a long-ish refractor, wind-gust can screw things up for a little while, but only in winds greater than 10 miles/hour. To me the price/performance ratio is incredible.

I've added a FWHM estimate in the exposure time app. I will update it hopefully by the end of the week. See the pics on the last page

Some pics

In a few days I will update the app. Hopefully by the end of the week What I've added: 1. Changed the user interface a bit. 2. Corrected calculation of Image quality FWHM. 3. Added a simulation of Image FWHM so a user can see how this parameter changes with different airmass, guiding during the night etc. Also the user can see each term contribution to final FWHM so one can get an ideea on how to improve the setup 4. Cosmology module. Based on user redshift input, different calculations are performed like proper distance, comoving distance, recession velocity etc. The cosmology module also has a catalog search engine to Sinbad and NED in order to easily find redshift and other parameters. The user can search multiple targets and get a table result.

I found the conversion factor, 2.355, comes from 2 x √(2 x ln(2)). Seems autoguiding performance is rather important for the final FWHM. Didn't thought seeing could be bellow 2" at sea level, live and learn 😁