michael.h.f.wilkinson

I like trawling through star fields with big binoculars a lot. Much more relaxing than imaging, I find (unless the mount is ticking over happily and all is well with camera/filter wheel, scope etc). I remember a trip to South Africa for a family visit, and I brought along 15x70 bins. Just scanning these unknown constellations was awesome. Only after thoroughly enjoying the rich star fields littered with clusters and nebulae did I start identifying them with a star atlas. I then turned back to just scanning the skies. Brilliant relaxation.

7 minutes ago, Ardsley Astro said:

Scope is a Sky-watcher 130P Newt (Not the DS version), Canon EOS 500d with a 2x barlow to achieve focus. Mount is unguided EQ-AL55i Pro. I plan to purchase the Skywatcher 150P-DS before the end of the year. 

That is a fairly slow set-up, which makes the result more impressive. I work with a Meade SN-6 6" Schmidt-Newton at F/5. If you can somehow work at prime focus that would make life a lot easier. I used an un-cooled ASI183MC for my imaging, and needed extension tubes to reach focus, so that scope has a lot of back-focus distance. Could you perhaps bring the primary mirror forward, or get a low-profile focuser?

Some nice detail coming through there. This is not an easy target, I find. I have collected 8 h of data in the past, and still feel I need more (could be my sky quality). What scope and camera are you using?

Note, I have both the AM-5 and the HEM15 (closer to the AM-3 in specs). What I really like is the lighter weight of the HEM15, and the fact that it comes with a hand controller, rather than having to use a phone or tablet app.  Its polar alignment and tracking are rock solid, and it can in principle carry my C8 (never tried that, I should add) without the need for a counterweight. It does of course need a battery pack, and for that I use very compact 12V 12Ah Omegon Powerbank.

My old EQ3-2 (motorized) was quite good as a fairly light travel mount, now since replaced by the excellent iOptron HEM-15 with Carbon tripod.

A remote possibility is a "point meteor", i.e. one that is coming straight at you. I have seen two of these in all my years of stargazing, though none as bright as you describe. Mine were around magnitude 1 to 2, I would guess.

6 hours ago, Legalpusher said:

I am new to astronomy.
While searching for suitable eyepieces for my newly acquired Dobsonian,  I came across the Pentax 16.5 and 23.  My experiences with Pentax in my youth prompted me to buy them.  Compared with the OEM Celestron Omni 32mm,  I was happy with the purchase, and added the 40mm XW as well.  They were comfortable enough to use with glasses, although is much more comfortable without the glasses in between.  A months later, I bought a Tele-Vue Ethos 8mm, the 100 degrees AFO blew me away, I bought the 6mm as well.  They were comparable in comfort and view quality.  The wider view gave them a unique feel.  Don’t think I’ll be buying the 4.7mm soon.  The lack of funding, a common condition since I acquired the hobby, & the weather doesn’t favor its use, maybe later in the fall.  
The 4.7 TeleVue at 110 degree of apparent field of view probably won’t be used frequently due to condition limitations.  Should I buy a less costly alternative like a Nagler, Pentax XW, or skipping it totally?  May be a Powermate?  Having 4 mm and 3 mm eyepieces with the same field of view at the cost of 1/2 an Ethos is appealing.  What pitfalls am I not aware of? If any?
Waiting for a $40, 100mm Vixen eyepiece to replace my OEM red dot finder.  My arthritis prevents me from using it since day 1 totally.   How anyone able to use it on a Dobsonian is beyond my comprehension.  Can’t wait to see how it works out.   May be I should replace the red dot with a right angle finder for $80 instead?

 

 

What sort of Dobson do you have? in an 8" F/6 a 3mm EP is not that useful. I also find that in my 8" scope (F/10) I do not use my Pentax XW 5mm , although it does get used in the 80mm F/6 APO I have. I also find that the wider FOV is most useful at the lower magnifications, but for planetary work, the 70 deg FOV of the XWs is more than enough.

Finder-wise: I would go for a RACI finder. I have a 9x50 and a big 14x70 (home made) and they are so much better to use than an RDF or straight-through finder

44 minutes ago, Roy Foreman said:

Is your C8 in perfect collimation as that makes a huge difference with SCTs. When I first got the C11 I checked the collimation and thought I'd got it nailed but the resulting images were less sharp than your posted result.  For lunar bigger isn't always better as the larger aperture is more affected by seeing. The C9.25 is supposed to be the sweet spot. Are you using an IR filter? It makes a big difference. I like the Proplanet 642 as it let's through more light than the stronger versions. My images we taken before sunset so the sky was quite bright, and yet appears almost black even before processing.   Just a few pointers, but I know only too well what aperture fever feels like !

I have checked collimation and it cannot be far off if you get albedo spots on Ganymede. I didn't use IR on the above image (this was taken with my ASI182MC, and it has subtle colour). 

18 minutes ago, Roy Challen said:

Not necessarily! Hopefully it will continue as it comes back round😀

I hope so too, but it will be assigned a new number, no doubt

27 minutes ago, Roy Foreman said:

I did wonder if it might be an interference effect. I might try resizing the original and reposting. Glad you like the images. You don't need large aperture for good lunar results. A 7" mak or mak Newt will give stunning results too !

I have a Celestron C8, and I have had good results, but I feel I have pushed it to its limits, and want more.

49 minutes ago, Roy Foreman said:

Just looking at the full disc image and there appear to be stripes and squares on it.  These do not appear on the original, so I assume the artifacts are an uploading issue.  Anyone else had this ?

I see them too. If you look very carefully at the full-resolution images, some parts do seem to have a very fine stripe pattern. This could cause Moire effects when subsampling in a simplistic way. Very nice images. This is not good for my latent aperture fever.

Just got an alert on Spaceweather Live of an X-class flare (X3.48) and rushed out my little Coronado SolarMax-II 60 mm. Just beyond the limb, at the spot where AR3664 is hiding, there was an extremely bright spot, still apparently linked to the limb by a somewhat fainter bridge. Clearly, the flare is a parting shot from AR3664.

I got alarms on both SpaceWeather and Aurora apps, and as the sky was clear, I went to my favourite spot with relatively dark skies and clear northern horizon (Aduarderzijl). Nothing was visible with the naked eye, but My camera seems to pick up a purplish-red glow low over only the northern horizon. It was absent elsewhere. I took a series of shots with my Canon EOS-M6 mk-II, with Canon 22 mm F/2 lens (similar to 35mm in full frame), and stitched them in MS-ICE. A tweak of curves in Gimp gives this result

Not brilliant, but because the purplish red colour only appears to the north, I do believe these are my first northern lights

My score is 99%

16 hours ago, Flame Nebula said:

Hi

Previously, I've seen several posts discussing these. In this country sirius B is hard, and the e/f stars particularly f, elusive. 

My own experiences have failed with both, using SW80mm ed and 127mak.

My future weaponry is going to be the 200pds (95%probable now) on an AZEQ6. Secondary weaponry, a used SW120ED (50%probable).

I would like your opinions/thoughts/musings, on the chances of either of these scopes bringing home these astronomical delicacies? 🤔

If I recall I seem to remember John producing a nice sketch of the Pup from the 120ed. 

Location: outskirts Nottingham, bortle 6 sky ( in theory) in case this info helps. 

Thanks 

Mark 

 

I have seen both the Pup and E and F in a Celestron C8, so an 8" Newtonian should be fine, but good sky conditions are a must

Just bodged together a cool pair of eclipse glasses for my little binoculars. One piece of Baader Solar Film and some cardboard from a six-pack of beer, plus some black tape, and the result works neatly for those with an interpupillary distance of around 73 mm.

Spotted one big sunspot plus a little one with them. I am currently in Stonewall, Texas awaiting the eclipse, but the forecast is not good, so I doubt I will be able to do any imaging. These SUNoculars will be ideal for potential quick glimpses through gaps in the clouds. Fingers crossed.

I will probably be visiting friends in Leon, Spain, which is also on the eclipse line. Not ideal as the sun will be low in the sky, but certainly a cheap option

80s seems about right, but 90s is also possible. Note that Vixen made quite a few items marketed by Celestron.

That is very nice indeed

I have readily seen the spiral structure in M51 from a very dark site (Bortle 1) with my 8" SCT, but it is very hard from my Bortle 4-5 garden. A 16" RC at work can readily pick up the spiral arms from the outskirts of the city of Groningen (Bortle 6-7 I would guess). I should add that the view from the dark site in Southern France with an 8"was more impressive than what the 16" could do from the city. Aperture is apparently less important than sky background. With M101 things are curiously different. Due to the low surface brightness I could not really see the arms  from a fairly dark site (Bortle 2-3) with my C8, but as my eye moved over the FOV, I got the impression of rotating motion, which is a common illusion when looking at spiral patterns. Using Olly Penrice's 20" Dob (Sir Isaac) from his beautifully dark site made the spiral arms stand out very clearly indeed.

1 hour ago, Scooot said:

Ah nearby then, we’re planning on watching from The LBJ State Park. I’m hoping the forecast improves, the one he sent me yesterday was for cloud around there. Although he says it’s often cloudy early on and clears up later. 🤞 

Fingers crossed!

I will be in Stonewall, near Fredericksburg, Texas.

That is pretty good. If you use automatic metering, spot-metering might be best, as long as the sun stays in the centre of the image. If there aren't any clouds, I would go for manual exposure (I will be using two planetary cameras with FireCapture, and will opt for manual exposure).

Very sad news indeed. Taken away far too soon. My condolences to his loved ones

1 hour ago, Ags said:

Interesting.... isn't that however the same as saying "we are developing a new stacking algorithm"?

Not really, this method simply detects structures (in stacked, linear images, so no  non-linear stretch applied) that are potential objects. Fairly uniquely, it handles nested objects (objects superimposed on others), unlike Sextractor, Profound or NoiseChisel + Segment.  We published a comparison paper in Astronomy & Astrophysics a few years back, and are working on several improvements. The paper is open access, so free to download.

This is a figure from an earlier work by Paul Teeninga, Ugo Moschini, Scott Trager, and myself, showing the difference between SExtratcor and our MTObjects method. The latter shows much more of the faint regions of the galaxy, and detects H-II regions in spiral arms, and superimposed stars as individual objects, rather than having them cause a fragmentation of the detected object as in SExtractor.

We will submit a paper on a multi-band version shortly.