Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.



Advanced Members
  • Content count

  • Joined

  • Last visited

Community Reputation

32 Excellent

About Whirlwind

  • Rank
    Star Forming

Profile Information

  • Location
  1. Have you checked you are running the right version of Python? A lot of older code uses Python v2.x whereas the current version of Python is 3.x. For a lot of astronomy scripts and programs they tend not to be compatible.
  2. Whirlwind


    The Moonlite Nitecrawler will probably work as it is an integrated electronic focuser and rotator. That would likely solve your back focus problem (but would need confirming). It isn't a cheap option though!
  3. Whirlwind

    Astrophysics - Maths Equation

    Another way, and the actual maths formula, of looking at the formula is 10 ^ (0.4x magnitude difference) which equates to approximately 2.512 ^ magnitude difference. (^ = to the power of) Hence 1 magnitude difference is 2.512 times brighter 2 magnitudes is 6.31 times brighter 3 magnitudes is 15.85 times brighter 4 magnitudes is 39.82 times brighter 5 magnitudes is 100 times brighter 14.47 magnitudes is 614,163.67 times brighter. The reason for why such a system is relatively arbitrary. It is correct that the Greeks came up with the system however there is a natural reason for them choosing this system....It simply relates to how our eyes/brain works. Our brains/eyes naturally convert flux into a logarithmic scale. In effect the brain does it's own non-linear stretch on the data to enhance dimmer objects and suppress brighter objects. If you imagine what a camera is like taking exposures during daytime then you can understand what would happen if we just used a linear scale. At night we'd see nothing, during the day we'd be permanently dazzled. As such the Greeks just interpreted what they saw and what we can still see today. A magnitude 4th star will look to us about twice as bright as 2nd magnitude star even though the actual flux is over 6 times less.
  4. Whirlwind

    Custom Procedure Codes to send mount to USA?

    Ah well, live and learn. I think the gear boxes are meant to be reseated once in a while anyway. Never really had any issues with the ra, but the Dec was by far too tightly bound when it arrived (likely knocked in transit). So I had to seat that one a few times until I got it right. The first tries it came lose quickly and concluded I was being a bit too timid,. However note to myself don't try and strip down the gearbox! Good to hear you are still happy with it though.
  5. Whirlwind

    Custom Procedure Codes to send mount to USA?

    Hi Martin I would agree that it looks like 21 00 004 is the CPC code you will need to use as this is the code for temporarily exporting goods outside the EU for repair. I doubt astrophysics will know this and only understand the American side of things so that duties aren't charged on the way in by the US. It does look like you have to complete and 'outward processing relief' form though before it heads out. Are TNT doing this on your behalf as an agent, otherwise you will have to do this yourself. Sorry to to hear about the Mach1 - what's wrong with it?
  6. Whirlwind

    Remaining dust bunnies, processing them out

    However all of these are going to be dependent on the system being used. The FSQs are well corrected sealed units so there is less likelyhood that these will show some form of aberration. There's likely a number of factors that come into play. What we do know is that the size of the shadowing is dependent on the distance to the sensor. The further away the larger it becomes, but the more diffuse as the effect s spread out over a larger area of the ccd. The reason we don't see dust from an objective is because it is so far away that effectively it has been 'diffused' to being not visible. On on that basis it then becomes a question of percentage change where changing the location of the sensor to the dust makes a noticeable difference. If the back focus distance between ccd and dust was 50mm and by focusing you changed that by 1mm then the difference in the dust shadow will be more significant compared to one where the back focus distance is much larger (let's say 150mm). It will also be dependent on the size of the pixels as you will be more sensitive to such changes as they get smaller. Hence it may not be a case that they aren't there in remote setups but they aren't noticeable as the setup as designed. However more flexible setups may find they are more susceptible to this kind of fluctuation. edit - apologies for the typos, I hate typing on an iPad.
  7. Whirlwind

    Remaining dust bunnies, processing them out

    It probably depends on which side of the focuser the flattener is. If you have the ability to put the flattener on the telescope side of there is a set of lenses much nearer the ccd (e.g. An Edge) then if you have any dust on the flattener then you may need separate flats if you change the focus position because you are so much closer to the dust. However I imagine that in most cases it probably isn't noticeable if you change focus position several times over one night as the stacking will likely reject the variations. It only becomes obvious when the flats are done at one position and the lights at another. My general suspicion is that these effects arise when there is some slight motion because something isn't quite locked down as tightly as you realise resulting in a slight shift and a residual 'ring'.
  8. What were you getting when you ran the application. Was it throwing up any errors? I've just ran it with photometry only data using the example HD 17156b data and following the guide https://exoplanetarchive.ipac.caltech.edu/docs/exofast/exofast_recipe_1.html And I am getting the following output in the results tab
  9. How have you created the text file? It loads better if it is tab separated not comma separated. Also be wary of using Excel or other Microsoft programs for creating such files. They tend to add in invisible characters into the text/csv files. Most professional astronomy software is based on unix which creates clean text files and hence it can cause all sorts of problems if there are hidden characters inserted by the Microsoft. There is another implementation here:- http://astroutils.astronomy.ohio-state.edu/exofast/exofast.shtml This gets you to enter in the data points 'manually' which usually clears hidden characters. Otherwise you can post the file and I can see if I can get it working. Ian
  10. NASA has an online tool to fit transits - https://exoplanetarchive.ipac.caltech.edu/cgi-bin/ExoFAST/nph-exofast You could try this. Just to note though you need the data in normalised flux (not relative magnitudes)
  11. If you want some online tests of the 120/150 then here are some. http://interferometrie.blogspot.co.uk/ Scroll down a bit to get to ESPRITs
  12. Whirlwind

    Star Adventurer Mini - opinions?

    The Mini Sam should be fine for 12mm lens. I used an 18mm at crater lake last year and got a decent image of the milky way despite the smoke from forest fires everywhere. Note that it was only a rough polar alignment so limited me to 60s exposures. https://www.astrobin.com/309623/?nc=all I also used a longer sigma lens for the solar eclipse (sigma 135-400mm IIRC) - I ran it about 300mm. That was more tricky (but worked) because of balancing the lens. There didn't appear to be any tracking issues, but these were very short exposures, but it stayed in the centre unless I made an adjustment. The real issue was with the connection screws which are difficult with this weight as they tended to want to unscrew if there was any unbalance. If you are going for a large lens/Borg and want to do long exposures then get a decent method of connecting your telescope/lens and the mini. Also at this weight you need a decent tripod. I've not tried long exposures at the Borg FL (400mm?) but I would be hesitant. On the other hand there may be ways of doing this.
  13. Whirlwind

    Stationary stars?

    So how would you measure that spinning particle. How would you instantaneously destroy everything in the universe without any signature left behind? How do you know that in removing everything else in the universe that stopped the particle spinning if you have nothing to measure it against?
  14. Whirlwind

    Stationary stars?

    It is impossible to know, it would be a metaphysical concept. Everything is relative, with only one absolute particle there is no way to measure anything. The concept of time, speed, temperature and distance wouldn't even exist in such a universe.
  15. Whirlwind

    Stationary stars?

    That's easy. It's an impossible question. If you assume a point like particle (so hence only one) - lets assume a photon. Then we can postulate the following:- As there is only one particle there is no method for measuring distance, as fundamentally distance has to be defined by the distance between at least two objects. As there is only one particle there is no method for measuring time because fundamentally that requires being able to measure an action (which requires measuring between two objects). Hence it is impossible to know

Important Information

By using this site, you agree to our Terms of Use.