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Found 4 results

  1. Hi All, Encouraged by my image of Uranus and some of its moons some weeks back, I decided to take on the challenge of viewing and maybe imaging Sirius B with my CPC 1100 for the first time. At 9:00PM Sirius was at about 45 degrees - sky was completely clear with a limiting magnitude of about 4.5 and almost no wind. With an 8mm Baader Hyperion at 350X I was convinced that I could quite easily see a tiny spec between the flaring "spokes" of the main star. With the eyepiece pointed straight up I saw it to my lower right and estimated that it's position angle was thus roughly almost directly east (90 degrees). I checked this up on the Internet later and it seems correct for Sirius B. It's separation from the main star of around 10" (which I knew before) also seemed to be correct. I asked my 9 year old daughter and my wife to take a look (I asked them to look for a faint star close to the very bright star and tell me it's position) and both were in agreement with myself. Neither of them can be considered experienced observers :-) I then attempted to image the pair with my Sony SLT58 DSLR. I started at ISO 800 and took several images at each of 20, 10 and 5 seconds. Viewing these on my computer I was initially disappointed seeing nothing of Sirius B on the 20 and 10 second images, but then felt I could see a bulge on the main star in the 5 sec images. I dropped the ISO to 400 and took images at 1 and 0.25 seconds. Below it one of the latter converted to PNG format from the RAW and cropped. No further processing was done. Hope you enjoy!
  2. Report for the evening of 16/08/2018 With a clear night forecast I decided to try and get in a long session. The plan was to start with the crescent moon, work through the planets, throw in a few faint fuzzies and if the weather and I held out, finish with M31 sometime in the early morning. So, having set out both scopes earlier to settle I began with the moon. I really like these early phases of the moon as you can make a start before it’s even dark, and as it gets darker the more you begin to see on the surface. On view last night were some great features. The crater pair of Hercules and Atlas, the Mare Nectaris and the overwhelmed crater Frascatorius. I’d got my sketching stuff out hoping to have a go and was trying to decide which to have a go at when a stubborn low band of cloud rolled in and covered that part of the sky, so no sketch tonight. ? Well, over to the other scope, the 8inch newt, and lets just do a star test to check collimation. As it was still only getting dark I picked a brightish star at random with a low power eyepiece, defocussed and then swapped in a more powerful one. After a short time fiddling I was pretty happy with this but no matter what I did one side of the out of focus star image looked distorted. Was the mirror pinched or something wrong with the eyepiece? In the end I settled for what I’d got and focussed down to a lovely sharp pair of points! Doh, I’d picked the double star Rasalghethi! A lesson learned there. Still I really enjoyed the view of the main orange star and its bluish smaller companion so think an evening of doubles is on the cards sometime! Early views of Saturn were plagued by the same cloud bank that had covered the moon, but eventually it cleared and Saturn and a few of its moons were well worth a look. Also, worth some time were the lovely Messiers in the same patch of sky. M8 the Lagoon, then a whole patch of M’s including lovely open and globular clusters each worth time, but I had to push on. Mars was just clearing the trees so I sat down to see what I could see in terms of detail with the binoviewers. I tend not to look at what it is supposed to look like beforehand as I think the mind has a way of seeing what it wants. So, with Baader Neodymium and UHC filters to swap in I decided to sketch what I could. The UHC helped to darken those dark features but it also seemed to exaggerate the atmospheric distortion. After about an hour I went to compare my sketch with the view shown on https://astronomynow.com/mars/ Pleasingly my view was broadly the same, though lacked the detail. I didn’t see any straggling Perseids last night but did catch a couple of bright meteors, probably Northern Aquarids. By now around 2am, the sky was as dark as it was going to get, about 20.7 sqm, which isn’t the best its been here, but still good enough to see plenty of milky way stretching overhead. A quick view of M13 always makes me smile…so many stars but I moved on via another globular in Sagitta, M71. Much smaller than M13 but still sizable enough to start picking out stars with 8 inches, albeit with averted vision. On to M27 to spend a little time seeing what I could tease out. Clear without any filter the UHC definitely added to the definition, and the dumbbell shape was obvious against the broad white slightly elliptical smudge. Again, averted vision helped to give the hint of some structure to these edges. So, onto the Veil. It’s easy enough to find where it should be by hopping along from Sadr to just past the next bright star Gienah but honestly, I’ve struggled in the past and been underwhelmed. Well tonight with no moon and good transparent skies it was great. The eastern part C33 was just there, faint but obvious enough against the background stars. Pop in the UHC an it goes up a level. Swap that for the O111 filter and it was even clearer. Big too. Curving gently away out of the field of view, I followed it until it petered out then moved back and forth from end to end trying to find more detail. I moved over to the Western part C34 and again, there it was, particularly around the star 52cyg but other parts were visible as well, though not as clear as the Eastern section. I was really tempted to try a sketch but tiring so will leave that until another day. Last I tried for Andromeda to round out my nights plan, but by now it was around 3am and high thin clouds were moving in and the sky noticeably brightening, so it was time to pack up. I’d had a really good session, despite a few early clouds and a Homer Simpson Doh moment with collimation. Should tide me over until the next clear spell. Thanks for struggling through this and hope you all had a great starry night too. Dan
  3. I saw a comment that there were a lot more double stars in the sky than listed in Norton's or in a GOTO scope database. I found my way to the Deep Sky database (http://www.virtualcolony.com/sac/) and a list "Double Stars With a Constallation" (http://www.virtualcolony.com/sac/star_search.html) which gives a list sorted for minimum brightness, magnitude difference and separation. I generated some lists with parameters that would not overtax my 127mm Mak, and was gobsmacked at the result. For Lyra, I got a list of 27 doubles down to mag.10 Armed with the printed list, I set about finding them in the sky. Equipment: 127mm Celestron Mak on Nexstar Goto mount, 8mm Celestron X-Cel eyepiece & 25mm Celestron stock eyepiece. Out of 18 doubles I looked for, I was able to find and resolve about 13 in a little over one hour. Sky conditions: Urban, full moon. None of them were as pretty as the bright and well-known doubles, but it was an eye-opener to discover how many were out there. I would submit that this exercise would have been impossible (or at best very frustrating and time-consuming) without a Goto mounting. All I had to do was key in the RA and Dec, and since I had used Vega as an alignment star I did not even have to swap out the high-power eyepiece between stars. I wonder if it's possible to import these databases into a format suitable for remote control of a Nexstar?
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