[Dawson]

That is another good idea. Thanks.

On an SGL thread I started on this topic, someone suggested a bit of software which uses a webcam into a PC and does real time light curves, which is brilliant and I think is the solution I’d go for. It needs Adobe Flash and I can only get it to work in FireFox, but otherwise it is very good:

http://www.planetarium-activities.org/shows/sp/lightgrapher

The other thing the SGL thread has raised, which I had thought about and won’t factor into my model, is limb darkening of the distant star. All interesting stuff:

https://stargazerslounge.com/topic/342034-exoplanet-transit-model/

James

[Dawson]

My DIY/electronics mate thinks he can do something with an Arduino / Pi to detect and display the data real time, like this:

https://www.instructables.com/id/Plotting-real-time-data-from-Arduino-using-Python-/

I’ll report back.

James

[Dawson]

Dr Dan Brown of Nottingham Trent University has uploaded the talk by Alan Heath to You Tube, so everyone can enjoy it:

https://www.youtube.com/watch?feature=youtu.be&v=Srx6VE8UfGY&app=desktop

James

[Dawson]

Thanks.

This is a useful guide. We are looking at designing a course for beginners in astronomy at my local society, and this may well be a helpful “curriculum” on which to base sessions or discussions. Really helpful, thanks for highlighting.

James

[Dawson]

Thanks David. I think I have got stuck on the concept that it is the worst possible star for equatorial mounts and just assumed, without thinking, that it would be equally useless for alt-az mounts. I still struggle a but, because for less accurate alignments than the ones you are conducting, the user would be essentially pointing the scope at the same place in the sky every time they align, as polaris moves so little – I still struggle to see how this cannot introduce some kind of error, but again I think I’m over thinking it.

James

[Dawson]

Alan’s talk last night was a great success. A fascinating trip through the solar system and what the amateur astronomer can achieve, with a number of stories from Alan’s life. Both educational and enchanting. I’ve shared many cups of tea with Alan and heard many of his stories, but he still managed to share some new ones last night. He captivated the lecture theatre which consisted of young and old, experienced observers and interested members of the public. It was a privilege o hear him speak again. Dr Dan Brown who is the Associate Professor in Physics and Mathematics at Nottingham Trent University has recorded the lecture and this will hopefully be available online in the coming weeks once he’s had chance to slice the audio and video together.

After the talk we all went down to the university’s observatory for a tour and marvel at their 16″ Meade on a Paramount – makes me envious every time I see it. 

[Dawson]

Great. 

I gave a similar, though much less detailed talk to my local society a few years ago, I would loved to have been able to listen to your talk in advance of that to help me prepare. Sandra is always very helpful though so I picked her brains for ideas and images.

Thanks for sharing. Great stuff.

James

[Dawson]

I got hold of a Sunagot Delus Slide Duplicator second hand online. It looks like it was made in the 1970s or 1980s, so pre-digital cameras, so a bit confused what it was designed for.

Anyway, it works a treat on my Canon 6D. It is not easy to fit the full image of the slide onto the sensor even when the zoon is set to 1x (the minimum). I tried adding an extension tube but then I can’t achieve focus. It is possible to fit it all in the frame, but it takes a bit of time. Some images need a bit of processing on the PC once captured as the contrast and saturation can be off as the image of NGC 604 below shows, but others like Mars come out well straight from the camera. So in all I am VERY pleased with this method and look forward to digitising some slides to help someone prepare for a talk, and also to keep their slides for prosperity sake. [the slides below are comercially available ones I also got second handfrom ebay to do some testing; NGC 604 The Planetarium Armagh; Springtime Dust Storm Swirls at Martian North Pole, The Planetarium Armagh; The Sun, slide 679/10 Astronomy Slides, Rickitt Encyclopedia of Slides 1973]

Thanks for the ideas.

[Dawson]

Thank you. My Canon 6D effectively has a full frame, so I should be OK.

James

[Dawson]

Wow.

Never thought about using my DSLR! I’ve just ordered one from ebay. I will report back! Many thanks again.

James

[Dawson]

6 and 1 are not dissimilar in form, which should give you an idea of where 6 resides in the overall scheme of things.

7, I think the clue is the initial plateaux phase of the plot.

8 I think is just difficult!

Sorry.

[Dawson]

Thank you.

Thanks all. A non-astronomy friend is going to lend me something to try out, so I will report back. I am surprised the flat bed scanners (I have one) would have sufficient resolving power to convert a 35mm slide into a reasonable quality image, this may be something I could try with my own scanner.

Thanks all again.

James

[Dawson]

A great newsletter as always.

Was interesting to read about Firsoff and his climbing/walking.

James

[Dawson]

I did the star count last night and could count 12 stars from my back garden; 10 were easy to see, 2 were with averted vision. Will be interested to see the final national results.

James

[Dawson]

Lots of ideas above. I think this book is good as it shows you what features are visible throughout the lunar month. Secondhand copies can be sources online for under £10.

[Dawson]

Excellent.

I thoroughly enjoyed it. Best of both worlds; I got to hear the talks and stay away from the stinking capital. Well done all involved; I too watched on you tube. I think it worked well for 3 hours or so; I’m not sure I would have sat and listened to a full day. I especially enjoyed the SkyNotes, a very entertaining and informative edition; just far too much on variable stars 😉

James

[Dawson]

Excellent.

Great to be able to see the talks from home.

Might be useful if the slideshow of images playing at present were to have some text saying “we are having our coffee break, the video feed will return at about 16:15” or the like.

Great stuff.

James

[Dawson]

Thanks Martin. This was 120 x 30seconds, so an hour in total. I’m going to wait until it is higher in the sky and try for 60 second subs, and maybe try without the LP filter. I think the LP filter is also cutting out a good proportion of the cometary photons.

I’ve got an ZWO 224 (colour) but it’s not cooled so I suspect it would be vastly more noisy than my Canon and not significantly more sensitive, but maybe worth trying that too, but I suspect 30 seconds on the ZWO would be VERY noisy.

Food for thought, thank you.

James

[Dawson]

Give up…

Will try again in 10 days when higher in the sky and I can take longer subs. Stack below from DSS trying to focus on the comet and the stars. FoV 5.93 degrees x 3.95 degrees; focal reducer flattener is designed for cropped sensors, not full frame sensors which is why I think there are still some obvious gradient rings from some vignetting despite making some flats.

Video of the comet moving over one hour also available here, but 200MB:
https://www.dropbox.com/s/gvtr6kk4mmoouio/IMG_7940_pipp.avi?dl=0

James

[Dawson]

I think the fundamental issue with my data is:

– subs too short, I will try 60 second subs, but not guiding so will have to get the PoleMaster out

– I stupidly shot in JPEG and need ot shoot in RAW

– I think the comet will be better when higher in the sky.

Here is one of my many stacks, where I forgot to identify the comet as a comet and it’s just stacked on the stars!

James

[Author]

Posts