andrew s

Not sure of your point. Scattering will leave a reddish brownish colour as in the image. Regards Andrew Rereading your post. I don't think the scattering is as you propose. The scattering will in an optically thick nebula will be roughly into 4 pi steradians at short wavelength scattering blue out of the line of sight the red less so leaving the reddish brown colour.

I think it could be Rayleigh scattering in in the nebula rather than our atmosphere. If in our atmospheric then the field G2V stars would be yellow. This could be a check on which it is. Regards Andrew

It may also depend on the spectra of the illuminating star or stars. Reflection nebula are often illuminated by very hot massive stars with most of their output in the UV. Cooler stars have their output mainly in th IR. With other stars filling in. So what you get will depend on the illumination, forward or backward scattering and the nature of any dust in the nebula. For very distant object interstellar reddening may also play a role. Regards Andrew

Good it's not fair if you hover up all the photons with the RASA. They are a great addition to the astrograph options. Regards Andrew

Very impressive and has a beauty in subtle shades. Regards Andrew

Thanks for flagging that up Nelson. Which eye do you use when observing. I see no clouds. Regards Andrew

Technology led doom has been predicted at least from the industrial revolution and probably back to the invention of the wheel. The reality is that technology has led to a longer life span, better standard of living and literacy across the whole world population . ( See "Factfullness" by Hans Rosling et al) Regards Andrew PS This may be judged as too politically so please delete if it is and accept my apologies .

Results are what count not acronyms. Well said @ollypenrice, although OSC is not good for spectroscopy given the light is already dispersed. However, with OSC you can do simultaneous photometry in three colours. While not classic photometry filter bands they can be transformed into them quite easily. Regards Andrew

Your obviously not subject to the black hole no-hair theorem. Regards Andrew

Must have been in an alternative Universe as it's not possible in ours. The big difference now from the not so distant past is that we have good physical theory that covers from the very smallest to the largest sizes and for very low energy to levels that we could never create (I.e close to the energy density at the big bang). While they may well be refined there is little room for warp drive and it's kind to emerge. Regards Andrew

Miror mirror on the the wall which is the farest of them all? Regards Andrew

Very happy with the term craft @ollypenrice as by choosing realistic art rather than abstract art I had intended your concept of realism. I had not fully thought through narrow band v broad band but accept your diagnosis. Regards Andrew

@ollypenrice felt the term "loaded" in another thread. Maybe it is, but to my mind it is the highest complement. I am not a imager, but when I look at the entrants to the IKO M16 competition I am reminded of the quality of the images produced during the peak of "realistic art" paintings. The skill and knowledge those artists displayed in the making, properties and uses of the materials they used seems similar to that displayed by Olly and his kind in the acquiring and processing of astronomical images. The sheer variety of the IKO M16 entries confirms this to my mind. One seems broody and pulls me into the core, while another is bright and reaches out at me. They all display the creativity and judgement of there creators. Clearly, they are not realistic in the sense of realistic art but if not art what are they? Regards Andrew

I don't think so. It's more to do with the details of the collapse of the molecular cloud and its net angular momentum. Regards Andrew

In theory a robotic interstellar mission would be possible. It could be a simple flyby mission with a LASER sending back the data. Regards Andrew

What type of filter are you thinking about? Coloured glass, narrow band broad band interference filters, UV / IR blocking? What are you trying to do with them on what type of object? We need some more context to comment. Regards Andrew

I found when experimenting with stacking files in PI and then saving them as fits it did not fill in the fits header data as you might expect. This may be a red herring as I was trying to then use spectroscopy packages not imaging. Regards Andrew

Spending too much time on SGL and with Tonka toys. Sorry Takahashi toys. Regards Andrew

I think what's best for you depends on several factors . How remote you are. What kit you have. What you are doing etc. I have a SB Paramount and the remote observatory uses a observatory control system that links easily with Voyager. Hence The Sky X with Voyager and apart from Voyager's verbose file names (which is changing) it allows me to do exactly what I want. Wait for astro dark and target at specific altitude image as I need stop either on specific altitude or astro light. Focus, slew etc as you will. Regards Andrew

Never doubted by me. Regards Andrew

You need a finder for the Sun. Are Takahashi scopes so magical they don't cast a shadow? Spooky 😉 Regards Andrew PS no Peter Pan Neverland jokes intended!

Why on earth would you doubt it now. You would know if you ... Regards Andrew

I have an FLI Atlas focuser no idea how it works but it just does. Interesting that a friction focuser (e.g. Crayford) is a no no but a friction mount is the bees knees. A question of balance I assume. Some Crayfords ( e.g. Van Slyke) had a spring to balance the increasing load as the altitude increased. Regards Andrew

Expectation bias is a major issue in many areas. Just look at HI FI as an example. However, my working hypothesis is to accept all visual observations at face value and look for scientific evidence to support such claims. Regards Andrew

Thanks, good to have some data. I thihk it is more often obvious with linear features where it seems common to see features below the limit e.g. divisions in Saturn's rings. Here it seems the visual system can discriminate finer contrast differences when they are extended. Regards Andrew .