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Lady Isabella

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Everything posted by Lady Isabella

  1. Hi Paul A most excellent sketch. I will stick my neck out and say that the spot is indeed real. I also observed it with my 102mm refractor.
  2. Hi Dan I think it's both of them. Looking at my observing logs, I notice that my best views of the craterlets cover a period starting a couple of days before and after the full moon. Even at full moon, I still manage to bag a couple. I once read an article that said that the full moon period was a good time to spot them, for they act like little radar dishes and reflect light back. At Full Moon, I tend to use a green filter which helps to highlight the bright little specks.
  3. Last night was amazing for the Plato craterlets. I turned my 102mm refractor ( magnification 200x) onto the moon and was gobsmacked to clearly see 4 craterlets. The view of craterlet A was the best I've ever seen. I've seen 4 before, but not like last night. The 4 were so clear, and all visible at the same time.
  4. Blimey Pete A great set of images. I was observing Plato last night and was taken by the shadows, your image really shows the shadow of the peak Gamma very well. You have also captured the craterlets extremely well. Last night I could not even pick up the centre one.
  5. Hi Paul Just compared your excellent sketch against mine made on the same evening at 18:10 UT, and my sketch ties in very well with yours. The cusps are bright, and it's interesting how the southern one extends more around the limb. (something that is showing up on all my recent observations). With you using a 203mm reflector, do you find that you have to use filters?
  6. Yesterday evening, Venus was visible in a break in the clouds, inspite of it snowing over the observatory. Could not resist in seeing how Venus would appear under such conditions (cloud features were visible in the reduced brightness of the planet) Fifteen minutes later, the roof was shut and it was no surprise to find everything coverd in 10mm of snow. The observation reminded me of the one made by Robert Stawell Ball on December 6th 1882, when he observed the transit of venus during snowy conditions.
  7. The long period variable star U Orionis reaches maximum brightness this month, and is currently visible in binoculars at around mag.7.5. It is a strong source of SiO, OH and water vapour maser emission. The star was discovered as being variable by J.E.Gore in 1885, and being close to Chi Ori makes it an easy to find object. Its typical range is mag 6.3 to 12.0 over a period of 368 days. 0.7' west of U Ori is the eclipsing binary star UW Ori.
  8. The carbon rich star R CrB, appears to be heading to an all time low. Its fade started in July 2007, when it was an easy binocular object of the 6th magnitude. Over the last couple of months, I've been estimating its brightness at around magnitude 14.5 from images taken with a Canon DSLR and 120mm f/8 refractor. AAVSO data and charts can be found here: http://www.aavso.org/publications/specialnotice/145.shtml
  9. Before buying a filter, I would have a go at making an Hexagonal mask. http://www.carbonar.es/s33/Articles/WhoWasThatMaskedDoubleStar.pdf
  10. This wonderful work has been posted on "Cloudy nights" by PJ Anway. There is a link where you can download the book. http://www.munisingwebsites.com/lookum/log/1011.html Also check out his website, wonderful double-star material on there. http://www.munisingwebsites.com/lookum/index.html
  11. This take by Roland Christen on flourite/fluorite http://www.cloudynights.com/item.php?item_id=388
  12. No doubt the dealer was peeved because you went for a TMB, for Takahashi have been building triplet refractors for 40 years now. The first one decribed as semi-apochromat was built in 1969, then in 1972 they brought out an 80mm fluorite triplet scope. Five years later a 90mm model was introduced. By 1983, the FCT range was in development with many models hitting the market by 1985. Over the years I've been fortunate to look through many fine and splendid refractors from different makers. But I have to say that one of the best scopes I have is my 30 year old Towa 80mm f/15 Achromat with its standard magnesium lens coatings. The planetary and double star views are simply stunning.
  13. Just as an interesting note, Sir John Herschel tells us about object-glasses built by Dr.Blair, that were free from chromatic and spherical aberration. These were made some 25 years before the Cooke triplet lenses. When the Cooke p-v scopes came out, they were regarded as being excellent, sadly for Cooke's, the new Schott glass that was used turned out to be reactive with the elements. This led to much public mud-slinging, with claim and counter-claim being made. A nice article on the whole episode can be seen here: http://www.europa.com/~telscope/hdtaylor.txt
  14. You could try using an aperture mask (70 -80mm), as Venus is showing some cloud features at the moment. I made a sketch about 8 hours before this chap in America: http://www.cloudynights.com/ubbthreads/attachments/2881841-01.22.09%20CED%202%20Venus%20by%20So%20copy.JPG While Sol Robbins has captured more detail in his sketch, I did managed to pick out the major cloud features that he shows, also the shape of the terminator. p.s. I also used a yellow filter.
  15. A great book indeed, the sections on telescope testing etc are superb. John Benson died on the 13th July 1958, aged just 42. Had he lived longer, then I'm sure the book would have been up-dated. A real shame, for this book is indeed a real classic.
  16. These Bresser scopes are very good. I once had the f/13 version, and that scope gave a staggeringly good star test.
  17. I started using a 7x5 shed, and it was not big enough. I now use a 8x8 roll-off roof, for my 5 inch refractors.
  18. Yes I agree with everyone, Rigel is not a hard double. Even a 50mm scope will pick it up, as was shown last night. I'm just curious why many books, magazines and now internet sources still continue to regard this double as difficult? Over 40 years ago Patrick Moore was telling us that the companion can been seen in small aperture scopes (i.e. 70mm), and I don't think it's got any harder to see over the last 4 decades.
  19. Searching through books and online, I see lots of varying information regarding the fainter companion to Rigel. Some say that you need a telescope of at least 100mm to easily see the companion, while another says that a scope of 150mm has to be used. The companion to Rigel. should be visible in scopes much smaller than the above sizes. Several sources I've seen knowledge this, but say that the glare from Rigel will make spotting the secondary very difficult. Last night, I made the following aperture masks, 80mm ,70mm, 60mm and 50mm, for use with a 102 f/8 refractor. At full aperture (102mm) the companion star was easily seen, however due to the atmosphere, the eyepiece view was a bit messy with alot of glare and a quite rough looking Airy disk pattern. Working down in size with the aperture masks, gave some interesting results. Instead of getting worse, the views got progressively better. At just 50mm aperture the view was most interesting. The companion was very easy to see at magnification 65x. Rigel produced a superb Airy disk pattern, with a near perfect faint first diffraction ring. With direct vision there was no glare, only when using averted vision was any detectable. Flicking back to 102mm, clearly showed the effects of low altitude and atmospherics. It would be inteesting to see how well the skywatcher range of scopes work with their 50mm aperture stops on this star.
  20. This evening, we were testing a Skywatcher 120mm f/8 Achromat. While using a 70mm aperture mask, we had a clean split at 222x. The secondary appeared to be located in the first diffraction ring/ inner edge touching the inner space.
  21. This is one star that I tend to observe in the warmer months, however it's worthy of observation on any clear night. Using 102mm f/8 refractor at 25x, had beta Cas and WZ Cas just about in the same field of view. The view is busy with lots of stars, however you simply cannot miss WZ Cas, its colour betrys it location, no other star in the field of view has the same appearence. This circumpolar treat is found within 2° of the naked eye star Beta Cas. WZ Cas is a semi-regular variable star, usually seen around magnitude 8.0. It is also a Carbon star having a very deep red-orange colour in the eyepiece. WZ also has a wide companion star (P.A. 89°, Sep 58.1") of the eigth magnitude, that is easily seen in small telescopes or large binoculars. There are also two more fainter companions of the eleventh magnitude visible in the field of view. In the eyepiece, WZ had the most gorgeous deep orange colour. While the 8th magnitude companion had the slightest hint of pale blue. The 11th mag companions were easily picked-up. I took an image with the digital camera, and the colours are wonderful. This is a real gem of a double star, that's well worth checking out.
  22. The cataclysmic variable star SS Cyg is currently in outburst. This evening it was an easy object in 10x50 binoculars, brightness estimated at magnitude 8.5. It should remain a binocular object for the next couple of days.
  23. Cracking good images. The dark cloud feature in the south was visible in the eyepiece this evening with a 80mm f/15 refractor at 160x. Seeing estimated at Pickering 9 this evening from my location. Your image also confirms the difference in size of the Cusp caps.
  24. I've been using the Antares model with my refractors and it works very well.
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