andrew s

I would use ccd Inspector from ccdware to look at your images. I think it has a free trial period. This could help you pin down the issue. Regards Andrew

But then, I took my wife and two daughters to see Saturn via a 8" reflector and got "oh is that it" and the quickly reverted to the house. For me the modern world of advertising is all about unrealistic expectations why should astronomy be any different. Sould we stop you top imagers/processors posting your images as I could never be bother to work that hard at it or even if I did fail. The modern individual should be fully wise to it and no more expect Hubble images visually than a certain coffee make me George Collney. Regards Andrew

Not sure it needs to be. They drift is due to the axis misalignment not the optic. Regards Andrew

I suspect he means image scale large enough to allow a pleasing "enlarged" image once cropped. Regards Andrew

For those interested in what seems to have happened as opposed to the hopes of the press here is an interesting paper from Emily Levesque and Phil Massey https://arxiv.org/abs/2002.10463 who propose " ...that episodic mass loss and an increase in the amount of large-grain circumstellar dust along our sightline to Betelgeuse is the most likely explanation for its recent photometric evolution" Regards Andrew.

Mine at Pixelskies runs without mouse, monitor or keyboard. Regards Andrew

If you mean going supernova it depends on which part you are talking about. The core colapse is very rapid seconds, this is followed by the colapse and rebound of the outer layers which is somewhat slower. The brigtning in the visible is due to the radio active decay of elements created during the "explosion". This can take a few days to peak depending on the type of supernova. Regards Andrew

Mon dieu, and you said you didn't have a mistress in your "I'm a Frenchman" post. Regards Andrew

Nice again Dave. How do you decide the exposure v sampling rare? Just trail and error,aim for a specific SN ratio or another method Regards Andrew

Nice work. How did you determine the minimum? Interestingly the O-C does not look linear so it might be more that a simple offset error. Regards Andrew.

Picard is a haunted man broken by his assimilation by the Borg, the loss of his friend Data in saving him and the loss of power and influence . I think this is portrayed rather well as are the other characters who are developing nicely. It is certainly not TNG any more than Voyager was but different and developing well in my opinion. The interplay of human, cyborg and android is a fascinating topic worth some exploration as we inch towards a world where AI will become common in everyday life. Regards Andrew

Sounds like you need teflon cut ti size. Regards Andrew

What size are you looking for ? I have some T2 metal spacers, much better, than plastic in my view. Let me know and I will see what I can do. Regards Andrew

Nice work with little scatter. Your a real expert now. Regards Andrew

But the decent was something else. Regards Andrew

Clear Outside is predicting 5 clear nights in Castillejar and with little or no moon are we going to be treated to some images from the rig this week? Regards Andrew

Can't you just use a sub frame during focusing? Pick a line and do a ROI round it. Regards Andrew

Dec calibration between -20 to +20 means point your scope at a declination between those limits. It seems to me you need to study some basics. It is fine if your not interested but you would find things easier if you understood the basic concepts. Good luck. Regards Andrew

Some filters have quite high light leakage out of band either in the IR or UV so stacking in that case may not be such a bad idea. If stacking I would go from narrowest to widest as the light goes target to camera to minimise reflections. Regards Andrew

Third Flare at a higher cadence ~ 15s (11s exp) binned 3x3. I was beginning to wonder if changing the exp and binning had jinked me. This time it was QY Aur Regards Andrew

The outer layers are very loosely held by the low surface gravity. The slightest push and pull can set it wobbling like a giant soap bubble in the wind. The internals have instabilities due to changing opacity with temperature and pressure leading to the multiple oscillations and periods seen. t's a very dynamic atmosphere. The core is not impacted much by all this which is why the latest changes probably don't have anything to do with it going SN any time soon. Regards Andrew

Collimation is a complex process. What you need and how to do it depends on what stage you are at. The aim is to get all the components lined up on a common optical axis. This includes the focuser, secondary mirror and primary mirror. The secondary does not have a unique optic axis and nor will a focuser if the tools or eye pieces can be offset with a locking screw or band. Even a star test cannot tell if the secondary is aligned properly. The more you understand the process the better it gets. I used a sight tube to align the focuser and center the secondary under it. Then a Cheshire to align the primary followed by an auto collimator for fine tuning the secondary. Once collimated try it in different orientations to see if it stay collimated (the auto collimator is very sensitive). If it shifts too much find out what is moving and strengthen it. If all this is too much trouble the advice in the posts above is fine. Regards Andrew

Beautiful image the HST will be missed the new scope will not have all the capability of the HST especially in the UV. Regards Andrew

It's a right of passage for Newt owners none of this just point a shoot as with the Frac boys and girls. Unfortunately, it is the poor design of the mirror supports that allow collimation, plus poor focuses that mean you have to do it at all. I had a home made Newt with a steel box frame and I drilled 3/4" holes in it and it did not need readjusting. Regards Andrew

Google is your friend. Regards Andrew