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Whistlin Bob

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About Whistlin Bob

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    Star Forming

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    Burton upon Trent
  1. Recently I’ve been struggling for ideas for visual observing. When there’s a clear night I keep going back to the same old targets, and whilst this is enjoyable, it doesn’t carry the same excitement of discovery. I think the root cause of this is not doing the leg work beforehand- I normally build target lists (often from other’s observing reports), but I’ve dropped out of that habit a bit of late. A couple of days ago, whilst contemplating a tricky work problem I picked up my old battered copy of “Turn Left at Orion” and started flicking through. In my first year of observing, it was this book that really got me going, giving me target ideas and helping me to find my way around the sky. As I’ve become more proficient it has gradually fallen out of use, but flicking through it I found I’d done what everyone probably does and gone straight for the showpieces. There are a wealth of other targets along with nice little narratives. So, last night I worked my way with my 14” dob through pages 180-189 of my 4th edition. I used Sky Safari a little to help with the navigation (it makes it so much easier), but otherwise this is a session done Old Skool! Mars: Alright- this wasn’t on the list, but you can’t ignore it, sitting there so prominently. I’ve become a bit spoiled in this apparition, having had quite a few outstanding views of it. Last night was a bit murky in comparison with the best of those, suggesting thin cloud, but I was still able to make out shading on the surface and the distinct solar cap. It’s been a wonderful target these last 6 weeks and I’ll really miss it when it has receded. Almach: Incredibly I’ve used this star to navigate many times, but never actually looked at it in the eyepiece. What a beauty! Very bright and to my eyes it looked blue and almost white with a hint of yellow! 59 Andromeda: Like two blue cats eyes, nicely separated and evenly matched. 56 Andromeda: This pair was a touch fainter and a less vivid colour, but more of a golden colour with a wider separation. It took a bit more finding, sat on the edge of a relatively sparse open cluster NGC752. With hindsight, I was sticking too closely to the script here and should probably have dropped in a wider eyepiece to enjoy the cluster more. The Baader 8-24 zoom I was using is very good for dropping in and out, but the narrow FOV at 24mm doesn’t give the best view of extended objects like this. 6 Trianguli: A much tighter pair at 3.7”, but quite easily separated at 8mm. Lambda Arieta: A nice contrasting brightness, TLAO talks about contrasting colours but I can only see a hint of blue in the much fainter companion, whereas the primary seems completely white to me. 1 Arieta: Another tight pair at 2.9”, but quite easily separated at 8mm. Again, I was unable to make out a colour contrast. Mesarthim: A more comfortable split and a much brighter double star, apparently even brightness (combined mag 3.86). According to TLAO the orientation barely changes, suggesting that we’re looking at the orbit edge on. I was curious about the name of this one so researched a bit further- apparently it’s a corruption of nearby Sheraton; and as a star it appears in Chinese and Indian Mythology; in the latter as a doctor to the divine. It also gives its name to an Australian band who specialise in the Depressive Suicidal Black Metal genre. Who knew that was a thing? I’ll probably give it a miss… M34: Turn the page and here was a more familiar object. To me it looks sort of like a flower stalk, set against the rich star field of the Milky Way. This time I did drop out to the 30mm- a really nice view. The Double Cluster: Here’s an old friend, it even looks good in the finder. Sticking with the 30mm I was comfortably able to fit both sides in the same FOV. As well as the richness of the Star Field I love the different colours in this one. There are lots of tones of yellow and blue, and then a few deep red ones really stand out. Found myself in disagreement with TLAO here- it claims this is much prettier in a smaller telescope (a 4/4 frac view, but only a 2/4 dob view), but I find the view in my Dob for this one glorious- the number and concentration of the stars make this one of my favourite sights. On the other hand- I do like the way TLAO descriptions lapse into the whimsical- “the view from a planet in one of the clusters would be spectacular: perhaps a hundred stars in the home cluster would be far brighter than the brightest star in Earth’s sky, while the other cluster would be far more impressive than any open cluster in our sky”. Now there’s something for your dreams. The Pleiades: Having the 30mm in the scope and talk of spectacular open clusters made me take a detour to the Pleiades. Perhaps natives of the Double Cluster have a better view, but this one does me just fine. The electric blue colour and patches of nebulosity still visible even with the strongly illuminated moon. Yum! Back to TLAO… Iota Cassiopeia: This again is a familiar target; I find it a good test of conditions, especially when the Double Double is dropping low. I quite enjoy pulling it up at 24mm, when it looks elongated but single, and then zooming. At 20mm it’s already a double, but I’m at 10mm before the third companion starts to appear. By 8mm it’s a clear separation. Sometimes I can see hints of colour, but tonight they all look white. Struve 163: Another triple, but much greater separation. The A and B stars were showing fantastic colour- deep blue and orange, although the third was much fainter. This was another discovery for me, a lovely sight, I need to make this a regular stop! Eta Cassiopeia: Another pair of contrasting brightness, I found this quite a straightforward separation. TLAO claims sharply contrasting colours, but I couldn’t get this- just a hint of orange in the secondary for me. Burnham One: I struggled to find this one a little, and didn’t manage to split the A and B pair (1.1”- which is usually just in range for the dob). I should have tried a mask, but was more excited that the transparency had improved a bit and some clouds to the south were dampening the moonlight to the extent that I could see the PacMan nebula- something I’ve never managed from home before! Sigma Cassiopeia: This, at 3.2” was an easier split- the clouds were coming closer now… Struve 3053: Last view of the night and another new one for me. I had to be quick with the star hopping to beat the oncoming clouds, but got there just in time- and very glad I did. Quite startling orange and blue- a really lovely view. The encroaching clouds ended it there, but really enjoyable to get the buzz of discovery back. I would happily have turned the page for a tour of Cassiopeia’s open clusters, but that’s going to have to wait until the next time!
  2. Congratulations on your 300p @BiggarDigger- sounds brilliant. I umm'ed and aaah'ed about a bigger scope for ages before taking the plunge. I've never regretted it for a second. @procky1845 many people said the same to me- "you'll just pick up more light pollution" and of course this is true. But everything increases at the same rate and so on fainter objects, there's more light altogether and you still see more of the object. I have a 200p and a 350. In equal conditions (and I've used both scopes in Bortle 2 up to 6, home is Bortle 5) the 200p, good though it is, gets blown away by the bigger scope. The downside is that it's a big beast and takes a while to assemble and collimate, other than that it's brilliant!
  3. Love M33 as both a visual and imaging target. This is from two years ago, I think 3 hours of 5 minute exposures on a 130pds with a Canon 600d and an IDAS D2 filter.
  4. It has taken me ages to get this one into a state where I'm happy with it. I think part of the problem is that the IKI observatory published their data on the same target on the same night I was imaging this. I've been having a lot of fun playing with their data, and when I started on my own data, my little reflector felt a bit outgunned. Think about it: Not only that- they've got 80 hours of integration time under a dark sky. I've got 3 hours in suburbia. With LED streetlights. You can pop over to the IKI thread to see how their data turned out, but all things considered I think the 130pds acquitted itself pretty well. My data was: 20*30 secs each of RGB for the stars, 60*60 secs Ha and 90x60ses Oiii all at gain 250. The channels were mixed HOO, with the Blue at 150% to give the oxygen envelope around the nebula a blue tone. I had a lot of trouble trying to balance the brightness of the crescent with the background nebulosity- in the end I did two versions in Pixinsight, one for the Crescent and one for the rest and then merged them as layers in GIMP.
  5. I have a 200p that I use for imaging and I use Skywatchers own coma corrector- for visual the coma isn't really had enough to trouble me, although others don't like it. It works well with both DSLR and dedicated astro cameras, plus gets me imaging at f4.5. I do sometimes have reflection issues with NB filters and very bright stars that are worse when the cc is in the image train.
  6. This. It doesn't make an enormous amount of sense to me, but I have found it to be completely true. M33 was an object that I failed to see at home for a very long time, despite pretty strong equipment and many attempts. Then when I did find it, it was quite underwhelming. But over time I've had a few really good views, and I'm pretty fond of it as a target. I guess it must be simply that you learn what works and what you can expect from the sky conditions on any particular night.
  7. I have a pair of these, and on the right targets (lunar, planetary, globs) they deliver phenomenal views, although Newt owners may need an additional Barlow. Good luck with the sale
  8. Well done to the winners and everyone who took part
  9. I use very think heat holders gloves with the tips of the thumbs and right first finger snipped off and sealed with duct tape (!) Cheap and works very well!
  10. What a brilliant project and beautiful scope. Thank you very much for sharing.
  11. Couple of different processes of the Wizard nebula. The acquisition details are: R,G,B – each 20x 30s (Stars) Ha,Oiii,Sii – each 100x 60s (Nebula). All at Gain 250 on ASI1600mm with ZWO filters, HEQ5 with, of course, 130pds using SW Coma Corrector. There’s 2 presentations: the first is SHO, but with the green channel then mostly re-distributed into yellow and blue, the second is more naturalistic with Ha and Sii fed into Red and Oiii into blue and green, with a 50% multiplier on blue and a reduction in Red where Oiii is present. So not very naturalistic!
  12. Here's my HOO effort. Exactly the same technique as my SHO version above, but with the channels fed as follows: Red= Ha at 100% Green = Oiii at 75% Blue - Oiii at 150% Plus I didn't desaturate the stars. I was happy with the colour mix compared with other combinations I tried, but then looking again at some of the others here, have I made mine too blue? I think you could process and re-process this indefinitely with different tones and hues!
  13. Great write up... making me wish my bins had filter threads!
  14. Like a few others I found this one a bit trickier to process than the M16 from last month- despite the strength of the data. I've played with SHO and HOO on this; I preferred the SHO, but might try and do a HOO as well if I get some time. The process I used is below; this is all in Pixinsight: - Rotated Ha image to the direction I prefer then registered the other images to it. - Clone each channel and stretch them to mask for Noise Reduction (though noise was fairly minimal) - Use Multiscale Linear Transform for noise reduction, quite strongly at single and double pixel scale (threshold of 3 and 3 iterations) and gently ay 4 pixel scale (1 and 1) - Masked Stretch on each channel - Bit of curves to enhance them further. - Clone each channel, create a star mask, invert it to protect the stars and then remove the nebulae and smaller stars. - Apply Starnet to the original channels to create Starless version - Combine the Channels as SHO - I usually try and use Hue and SCNR to give a less green / more golden appearance, but it really didn't seem to improve this data. - Instead, I held the green and red (there's not much Sii in any case) and boosted the blue to stop the green being completely dominant and try to enhance the lovely oxygen envelope around the Wolf-Rayet shockwaves. - Luminance mask and another round of noise reduction similar to before. - Invert the mask and enhance detail; I found the MLT didn't work well on this data and so used a mild Local Histogram Equalisation instead. To be fair- it's pretty sharp already! - Finally, add the stars back in- I couldn't get colours I was happy with on this, so I mostly de-saturated them instead. Again- it's been a pleasure to process such strong data and to compare what I've come up with to other peoples images. It's really interesting to see how different peoples preferences are. Looking forward to the next data release!
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