michael.h.f.wilkinson

Just had another brief look under moonlight and a slightly hazy sky, using the Helios LightQuest 16x80mm bins. The comet is nearly overhead, and although it is not naked eye under these conditions, it is a great binocular target. The comet seemed a bit more elongated than the view yesterday, and a stubby, slightly fan-like dust tail seemed to appear. I seemed to spot some hints of the ion tail, but it was difficult to be sure. I don't have time to do some imaging, as I have to get up early tomorrow, but I am happy to have had another peek at this visitor from the more distant parts of the solar system. Fingers crossed for more chances later. At least I managed to see the closest approach.

I removed gradients and calibrated the star colours in Astro Pixel Processor, and got this result after a slight tweak in GIMP: This is the colour I would expect without stretching saturation

Is it perhaps some internal reflection caused by moonlight?

I have just spotted it from my Bortle 4-5 location, but due to moonlight, haze and encroaching city lights I only spotted it with my binoculars (first the Zeiss Victory SF 10x42, then the Helios LightQuest 16x80s). Both showed it easily, with the 16x80 definitely giving the better view. No point in trying to image with clouds moving in

Depends on what you mean by "right". I do not see our understanding of the compositions of stars change any time soon. The claim of mainly hydrogen and helium, with varying amounts of "metals" is very solid indeed. The diameter, age and evolution of the universe are much less known, but we can state what the current best theory is. We can certainly with 100% accuracy state what theories are just wrong (like the flat earth theory).

Largely hydrogen and helium, plus varying amounts of what astronomers call metals. It's all determined from spectra. Of course you might want to invent some exotic models in which esoteric substances are involved which just happen to have the same spectral lines (down to Zeeman-splitting properties), but Occam's Razor will cut these models down quite easily

No it doesn't mean we are the centre, it just says we are at the centre of what we can observe, because the universe has a finite age (which is really the only logical conclusion to draw from Olber's Paradox). This argument has been given in this thread before, but you apparently didn't understand it, or otherwise missed it. You give no argument as to why this is not real science, so I do not feel the need to reply that non-argument.

Years back I bought a cheap pair of Celestron 15x70s (BA-1s, cheap and cheerful ones sold under a variety of brand names). They turned out to be faulty, but the seller provided me with an Omegon-branded alternative, which was a lot of fun to use, until the bridge broke (just as a replacement pair of far better 15x70s arrived: Helios Apollo 15x70 HDs). These have since been replaced by Helios LightQuest 16x80s, which are actually a touch lighter than the older Helios Apollo 15x70s. The cheaper 15x70s are usually actually 15x64 or so, and quite light (some 1.5 kg). This light weight is not necessarily a good thing, as I found the Helios Apollo at 2.5 kg easier to hold steady, and likewise for the 2.35 kg LightQuest. I generally use them hand held, but I know many people have issues. My Benro monopod with pistol grip and ball head does improve the views, and isn't too cumbersome to use for quick sessions. I use a p-mount (home made) for outreach only, as it is more of a hassle to set up, but allows you to share the views much more easily.

Photons don't have a to have a finite lifespan (in fact, they are literally timeless according to general relativity) just a finite speed. If the current, most accurate estimate of the age of the universe of 13.8 billion years (i.e. obtained by scientific method, nothing to do with theology) is correct, we can only see photons arriving from 13.8 billion light years away at this point in time. As the universe ages, light from more distant sources will arrive. In fact, according to current scientific understanding, the early universe was too dense and hot to be transparent, and the heavily red-shifted glow of that early phase is the cosmic microwave background radiation. This must be from slightly less that 13.8 billion light years away.

Might be similar to internally focusing camera lenses in design. Not sure why this would be a game changer, until the specs are more clear

Update: I had another look just now, and the dark blotch and bright flare have vanished. In that location there s only some minor plage to be seen. My best explanation for what I spotted previously is that there was indeed a flare going off when I first observed, and that material was being blown out, causing the dark structure just below. I most likely detuned towards the blue wing, and the filament structure I spotted was moving at quite a pace towards me, and therefore still visible.

Just had a look at the sun with my Coronado SolarMax-II 60 mm in single stack, and the amount of activity is staggering. The huge sunspot just south of centre disc is out-classed by a smaller AR towards the two o'clock direction. It shows as a very dark smudge lined by some extremely bright plage on its northern edge. It really looks like it is flaring. De-tuning the etalon shows this AR as an almost linear dark feature. I am not sure if this is a weird sunspot, or a very dark filament that still shows in the detuned image. The other filaments seem to vanish, so it is likely the former, but I have never seen such an elongated sunspot. Back to the tuned image, there are two thin proms on the edge at the two o'clock position, one very tall, and a shorter one. Some lower proms show on the western limb as well. Back on the disk, well north of the big sunspot, there is a very complex area of plage, sunspots, and filaments. To the south of the big spot several filaments can be spotted, one thin one running nearly north-south, and and one broad one more westwards. I hope I have time to have another look later, to see how the potential flaring area evolves. Well worth a look if you have a chance

Finally managed to image it, using my APM 80 mm F/6 triplet with 0.8x reducer, and ASI182MC-Pro. Here is a quick process of about 5 minutes worth of data. The comet is alreadt slightly smeared. Will try a better stack, ideally of all 30 minutes worth.

Finally a clear night, and imaging again. Got the ASI183MM and Samyang 135mm clicking away on the Flaming Star Nebula and surroundings. Fingers crossed the skies stay clear

If they did that, the mighty Nagler 31T5 "Panzerfaust" would likely go. That is one of my most used EPs, I must add. Really love it in the C8, but in the Meade SN-6 6" F/5 Schmidt-Newton and the APM 80mm F/6 triplet, it really comes into its own regarding wide-field viewing.

I have never had ergonomics issues with the Nagler 22, but then I have the eye cup in the lowest position, where it seems to happily stay put. The XWs are very comfortable (I have the 10, 7, and 5 mm), and for the Delos EPs I can tighten the eye cup position well enough so they don't budge. I made my Delos 8 and 6 mm parfocal (with a ring) with the XWs, which is ideal for planetary observation, when you want to switch magnification to adjust to the conditions.

Just read the comparison of the XW 23mm to the Nagler 22 T4 on CN, and the Nagler is safe in its place in the EP case (until ES decide to do a 22 mm 92 deg)

Somehow I missed this thread. The 16.5 isn't that interesting for me (I have the ES 92 deg 17 mm and 12 mm EPs). The 23 mm would offer a slightly larger FOV than the Nagler 22 mm I have, but I wonder if the switch would be worth it. The ES EPs replaced my Nagler 17 mm T4 and 12 mm T4, and proved a step up both in performance and FOV, but the 22 T4 is in my view the best Nagler I have, and just 3 deg extra is perhaps not worth it.

Spotted the comet this morning easily with my Helios LightQuest 16x80 mm bins, then got out the Zeiss Victory SF 10x42 mm and it was also an easy target. Swung over to M13, and the size and brightness were very similar, with the comet somewhat elongated, and a bit more diffuse. I would put the comet at magnitude 6 or so.

Very sad news. I always found John's posts very informative. My condolences to his family and friends

Lovely images, really nice and sharp, without any over-processing

I certainly didn't see the thin gas tail, but the dust tail is evident from the elongated form

I have to get up at 6:30 anyway, so might as well have a stab at the comet

I noticed the skies were showing some large clear patches early this morning, so despite moonlight I trotted out the Helios LightQuest 16x80 mm bins and had a look. The comet had moved significantly since my last sighting, so it took a while to get to the right spot, at which point clouds interfered. I went back to making breakfast, but kept an eye on the weather, and at 7:15 I spotted another large clear patch. This time I could clearly spot the comet, showing up as a much more elongated patch of fuzz. The dust tail was clearly visible, but no hint of the ion tail. No chance of imaging, of course, but at least I have had another sighting of this comet

Very nice result!