saac

If the object was accelerating through then as we take and then retake the red shift measurement we would see it progressively change reflecting the change in velocity. Jim

Swapped out my RedCat setup for the Esprit120 which I think I'll be using in visual mode for the next few weeks as it is starting to get light well into the evening. I bought the Esprit 120 about a year ago and I still haven't really put it to work on imaging -I've been having too much fun using the RedCat. So this is really the first proper shakedown with the 120. Tonight I will be mainly looking at the Moon - it looks glorious, nice and sharp and no colour fringes whatsoever. I'm looking forward to playing around with this over the next few weeks, I'm going to keep it in visual mode until the autumn arrives. Jim

Yes that is a bit of an uncomfortable watch. Mercifully no lasting damage but maybe a lifelong lesson learned. Jim

In truth stars will have an acceleration component to their motion for a number of reasons; for example the rotational motion around their galaxy's centre of mass. That change in direction by definition means the velocity is changing (even if there was a constant speed), in turn by definition acceleration. This is what we measure when we detect a star's radial doppler shift as it rotates in its orbit around the centre of mass. So at some point we will detect a red shift and at others a blue shift, and inbetween a changing red and blue shift. A star that is not gravitationally bound to its galaxy, so called rogue or intergalactic stars, will travel through space at a constant speed unless they come into the influence of say a black hole or other concentration of mass. Here the star will similarly accelerate until it either collides or is caught in orbit. But a star that is accelerating like that, say along our axial line of sight, would present with an ever changing red shift/blue shift. Just as you said red shift can also be caused by the cosmological expansion of space (recessional velocity) independent of the star's relative motion to us due to its motion through space. I'm not sure how they differentiate between the two, most likely the red shift due to expansion is a known component and rather like a background count rate of radiation it can be separated from the "motion" red shift - I guessing here. We need an input from Andrew S here. ps - just an after thought. From what I understand cosmological expansion does not impart motion onto bodies in space - rather it is the space between these objects that is expanding - the motion of stars remain dominated by gravity. Any motion that a star has then comes from either conservation of the momentum from the gas cloud from which it formed or from a gravitational attraction. As far as I'm aware cosmological expansion does not impart motion onto the galaxies/stars. Jim

Doppler redshift is a measure of the stars motion due to velocity not acceleration. and it is measured along the axial line of sight. However stars also have a tangential velocity from which they derive "proper motion" To determine the combined motion of the star one would need both properties. Typically a measure of the star's proper motion would be taken by position measurement taken a few years apart. So to answer the OPs question if both stars show red shift then all we can conclude is that their axial line of sight motion is away from us. To determine their true motion relative to Earth would also need information on their tangential velocity. Jim

It's a nice looking product and it does makes sense. It would make for a really clean and much simplified setup. Dare I say it, providing a high end smart telescope setup with swappable telescope ability. What would concern me is that by combining the individual components you lose all if one fails. Look at the recent issue people have experienced with firmware updates on the AsiAirs. That said, I'd love to have one but the price/weather usage ratio is a bit high for my budget. Jim

Postie just delivered a nice aluminium case for my Raspberry Pi5 and a rather cute round LCD display I now need to find a suitable project lol. Jim

Do we need an emergency alert sticky banner along the lines "Get Out And Look Up Now - No Seriously Do It" Maybe with an audible alert along the lines of the Enterprise Battle Stations. Jim

I think your last point is really pertinent. It's a clever solution nonetheless but I wonder how necessary to the average astrophotographer. Jim

Surely that depends on the length of your nose Hey wait a minute, is nose eyepiece rash a thing? Need to do an investigation at the next star party - spot the visual only people lol. Jim

Comparison with night vision doesn't really make any sense as these are completely different technologies not to mention price bracket. I also wonder if astigmatism would be anymore an issue than it would with a conventional optical eyepiece. Anyway, looking forward to this hitting the market and getting to read some early reports on performance. I like the thought of being able to move it from telescope to telescope - could really be a serious challenger for the emerging smart telescope market. I really do hope that they get the price point right on this - interesting kit. Jim

Exactly. As the saying goes "fly the aircraft" Jim

Nice work, looks to be solid. Jim

Set it all aside for a year and come back to with renewed interest. Jim

Gotta look for opportunities Jim

@maw lod qan - Wow look at that, it's sooo blue! Happy days You got to come back and tell us poor cloud dwellers what it was like Jim

If your longer term aim is to get serious about astrophotography then save the money for a longer term upgrade to your mount. Your mount is everything in astrophotography. Otherwise buy a SeeStar and have some fun and it may well keep the fire in your belly for you to save and go for some serious upgrades longer term. If you bought a See Star you would definitely have some fun with it and be sharing it with others. Once you are finished with it you can sell it to me to help fund the upgrade to a new mount Jim

We do like it though it's lovely and I want one Jim

I agree, that is a bit of nonsense. It is a bit of kit no more intimidating than say a camera tilt adapter. Ohh, well actually maybe poor choice there Jim

It also appeals hugely to those who do and have. When my hellishly expensive main rig is working away in the background I'd love to have access to one of these. Like I said, it's all about using the right tool for the right job. Jim

Never miss an opportunity to use engineering in astronomy; it is after all a technical discipline. Any bit of equipment can always be optimized and adapted else where is the fun Jim

Well you are now in the fortunate position to sell me one Jim

Wow, who would have thought such rivalry of philosophy exists within astronomy. Maybe it's the engineer in me but it's just a bit of kit, like any other tool it has a purpose. This one seems to do its job pretty well. I'd certainly give one a go, I'd use it to explore while my other permanently mounted kit is tied up with other tasks like, whisper it, photography! I don't feel threatened by it, it doesn't prompt any existential crisis of thought of what I'm doing with my other rig and cameras. It is just another tool giving a different opportunity to explore the night sky - there's no compulsion to buy one and it won't come and steal your babies from their beds at night! I hope to see more of these smart scopes being developed with the price dropping and capability improving. And as for that Smart Eyepiece by Pegasus, I'd give that a go too without feeling threatened by a lump of metal. Yep, definitely an engineers view Jim

Lovely report and really enjoyed your video. When I first saw M42 with a 16 inch Dob I felt like I was falling into the nebula, amazing experience with these large Dobs. Jim

I got a clear sky at the moment but the wind is picking up (Storm Kathleen) so unfortunately the observatory roof is staying closed tonight Jim