Nik271

Thank you for alerting me to this comet! I managed to see it last nigth (25 July) at 11pm just at the start ot nautical darkness. I was using my 100mm refractor at x40. It took me some trial and error star hopping to get to the right spot. Luckliy the comet was very close to the 7-th magnitude star HD93521 so once I was in the neghbourhood it was immediately obvious pretending to be a globular cluster. It is going to fade rapidly from now on. I'm glad I managed to see it this time!

Managed to see 13P/Olbers at 11pm last night with my 102mm refractor. It is reasonably bright right now, looks like a 7-th magnitude globular cluster at x40 and it is well positioned at 20 degrees up in the Northwest at the begining of nautical darkness. I saw no tail. Thanks to @michael.h.f.wilkinson for his post in the comet section alerting me to this comet!

Saturn, Mars and Jupiter at 4:30am this morning with my Skymax 127. I woke up early but the sky was getting brighter by the minute and I decided to give the planets a go. Saturn looks very different from last year: a pinhead with a dash across. I could see Titan and Rhea as well in the twilight. Next stop was Mars. An even smaller orange pinhead. I thought I spotted some dark marking but it was not conclusive. Jupiter was still low at 4:30am and I could just see the main belts and the four Galilean moons. Interestingly Io looked distincty orange in the bright sky, better than other times in darkness. All in all good early start of this planetary season!

It's probably a record for this solar cycle. I had a look in WL and the disc is peppered with many spots: https://spaceweather.com/images2024/16jul24/hmi1898.gif

I had my summer twilight tour of colourful doubles: Izar, Rasalgethi and of course Albireo. Used x50 in my 102 ED for Albireo, increased to x120 for Izar and Rasalgethi. The colour contrast of the orange and blue stars was very pretty. I could not stay very late and had to pack up by 11pm. Before I finished it was getting just about dark enough to spot the Ring nebula in Lyra as a tiny circle and verify that TCrB is still dormant. All in all very pleasant 45 minutes under the early evening stars. Bring on the astrodarkness, please!

I had another look at TCrB last evening at 11pm. Still dim, I had trouble seeing it at first in the twilight. It was dimmer than star 99 in the charts so somewhere in mid 10 magnitude I estimate. The reddish colour shows well when I stare at it for a few minutes. I used x50 in my 102 ED refractor.

Infinity is only an abstract concept, everything that we can see or measure in the universe is finite, even the number of elementary particles in every galaxy that our instruments have ever seen. But we can still speculate what is out there that we cannot detect. Here is the following thought experiment: imagine a race of two dimenionsional beings which live on some surface and are wondering: is it finite or infinite. There are some tests they can do to check. For example they can draw a large triangle and measure its angles. If the sum of the three angles is less than pi (and assuming their universe looks the same at every point), mathematics tells them that they live on a finite surface. If the angles add up to less than pi conversely they can deduce that they live on an infinite surface. And if the angles always add up to pi the test is inconclusive: the surface can be either finite or infinite. Here by infinite I mean in terms of area, or equivalently there is no bound on how many houses they can build all of distance at least 1 unit measure from each other. We have performed such measurements in our universe and to the best of our ability they tell us that space is flat. So the jury is still out if the universe is finite or infinite at this moment of time.

PS: One more thing since you mention dual mounting: the Skymax has a fixed vixen dovetail. This saves weght but it has the possible disadvantage that it can only be mounted on one side of Alt Az mounts, on the other side the finder shoe points downwards which makes the location of the finder very impractical. This is the case with my AZ5, so for grab and go I just put on the refractor.

Hi Ags, I have the 127 Skymax bought it in 2019. As far as I see on FLO the current model is still the same one. I have measured its aperure with the flashlight test to be 120mm +/- 1mm. The visual back is 1.25'' and maximal field of view with my Baader Hyperion 24mm is just over 1 degree. The Double Cluster just about fits in, but the framing is too tight, personally I prefer it a bit wider. It is one of the reasons I bought my 102 ED refractor, to be able to frame DC in a 2 degree FoV. On the Moon the Skymax is excellent. Rilles of Gassendi are easily seen (of course subject to seeing conditions). I can sometimes see the largest craterlet A in Plato. Personally I find about x120- x180 is the sweet spot, above x200 the view gets a bit soft. In my opinion the review by Roger Vine is spot on : http://www.scopeviews.co.uk/SW127Mak.htm Comparing it to my (low budget) Svbony 102 ED refractor on the Moon and planets I would say the Skymax is a bit sharper. Overall for planets and Moon I highly recommend the Skymax. A top quality refractor of 100mm will beat it but the Skymax has an advantage for compact size and portability, and of course its price it hard to beat. Nik

I fell asleep last night while waiting to get dark enough 😴 I will try to observe T CrB tonight while Pallas is nearby.

Awesome! I saw the big prom in the morning and it was quite impressive just like your photos!

Stellarium frequently gets the position of minor planets wrong unless you update their ephemeris regularly. This position above does not look correct to me for the night of 22/23 June. Here is what I think the correct position is which fits @Geoff Lister's image very well: I looked last night and Pallas had moved further down (i.e. south) closer to the pair of 11 magnitude stars

Nice report! The SM125 seems a gem, everybody who has it is very happy with it. I'm tempted... I struggle often with M4, but it is not the hardest of the Messiers from the UK. You need a night of good transparency near the horizon. Binoculars work best since the cluster is very large, almost the size of the full moon and visually does not have a dense brighter core like many of the others. I see it as dim oval nebulosity with difficulty in good conditions. I see M80 a bit easier because it is small and stands out as a fuzzy star in binoculars. Also it is 5 degrees north of M4 which helps a lot from our lattitude.

I was observing the Moon last evening. It was very low, only 10 degrees above the horizon and the seeing was quite poor so I was using low magnification, only x50 with my 70 ED refractor. Pythagoras was showing very well with its terraced wall and central peak. Next to it were several prominent craters in shadow which afterwards I identified as Desargues, Pascal and Brianchon. Next to them near the limb are also Poncelet and Sylvester. On the other side of Pythagoras are Markov and Babbage whom I consider also as mathematician (among other things). It struck me that these are all named on mathematicians, and in such a close proximity that it must be part of a deliberate plan. Does anybody know how thise craters got to be named? Nik

TCrB looked dimmer to me last night (1am UT 18/06). It seemed similar in brightness to the 10.6 comparison star which 15 arcmins north of it on the AAVSO chart. Forgot to look for Pallas though :-(