SteveBz
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Posts posted by SteveBz
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On 31/01/2024 at 12:41, athornett said:
More on Muon Detectors at European Astrofest on Saturday in London at 2:40pm!
Andy
Are you presenting?
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Hi Andy,
Great job, but help me here. What did you do? This what I think you did, please tell me if I'm wrong:
1 - Bought two RAA Muon Detector kits here: https://www.ukraa.com/store/categories/cosmic-rays/muon-detector-kit.
2 - And two enclosures here: https://www.ukraa.com/store/categories/cosmic-rays/muon-detector-enclosure.
3 - Assembled them both;
4 - Tested them with the Beta particles from a naturally occuring K40 source (bananas);
Is that right?
How do you then test for actual cosmic ray muons, and how do you distinguish between Muons and Beta particles?
Total cost was about £328?
Kind regards,
Steve.
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On 27/12/2023 at 12:37, athornett said:
got rotation curve and demonstrated dark matter
Flat rotation curve and dark matter aren't really the same thing. You got a flat rotation curve - amazing, but there are other explanations to the flat rotation curve such as MOND (Modified Newtonian Gravity/ Milgromian Gravity) or Quantised Inertia. Honestly none of these theories are really very intuitive. For instance, it seems very counter-intuitive to me at least, that the amount of dark matter that you need is an exact straight line from an apparantly random point midway out from the centre of the galaxy.
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15 hours ago, Astronomist said:
I was careful to buy mine from the rtl website, there are some very realistic looking fakes out there, especially on ebay and amazon. I think they are just using RTL's photos in their listings.
I can't find my fake just now, but they look realistic too. It's just the printing on the outside that's a bit different.
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16 hours ago, Astronomist said:
I found the RTL-SDR v3 worked well for the hydrogen line, although i haven't ever used a more expensive one to compare it too.
Yes, I think what's what mine is too, although you have to watch out for fakes!!
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Link or image? Maybe it's the one I got, I don't recall, we've just moved and it's all in boxes still.
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9 hours ago, athornett said:
I dont know if folks are aware of this new hydrogen tuned mesh antenna from Nooelec. Based on their 1.7GHz GOES antenna but little bigger and significantly pricier!
Mt initial review: below http://astronomy.me.uk/testing-the-new-nooelec-1420mhz-mesh-antenna-4-11-23
I have successfully detected hydrogen with it.
Andy
Fantastic. How much did it cost?
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Hi Andy,
It's a great start, but I think it's upside down. Here's a site arguing which way up it should be:
http://galaxymap.org/drupal/node/171
(NB EVen NASA got it the wrong way round
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Steve.
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5 hours ago, athornett said:
Thanks for that. Is that still the case as this is array rather than single antenna?
I'm pretty sure. What are the dimensions of the individual elements?
I think the rules are, resolution is set by the largest dimension (ie the array), the sensitivity is set by the elements.
If I'm wrong, Im suresomeone will correct me.
Steve.
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17 hours ago, andrew s said:
What's your interest in them?
I'm using them as a stepping stone into spectroscopy. I've joined a group of six or eight like minded folks to try to track a group after rapidly varying Be stars for longer periods of time than we might otherwise do.
I'm using a lowspec 3 and just putting the final touches to a star'ex.
Kind regards,
Steve.
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3 hours ago, andrew s said:
No, it's even better. But it was @skybadger
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6 hours ago, skybadger said:
Also try here http://basebe.obspm.fr/basebe/
Fantastic. This is the biz.
Tx.
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Hi Folks,
Does anyone have a list of Be stars? Especially ones currently earlier in the night. Eg in Lyra.
Kind regards
Steve.
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On 09/10/2023 at 07:21, athornett said:
I was very excited to find this thread today. I have myself been attempting hydrogen line observations and my work with some success can be seen at http://astronomy.me.uk/category/radio-astronomy/radio-observation-in-hydrogen-line-1420mhz
I am using an old 86 x 86 cm square phased military array that passes the "that looks OK on my patio" test carries out by my wife, whereas a 3m dish, however much I would like one, has been permanently banned!
What amazes me is that I am successfully obtaining hydrogen line traces in spite of living in the middle of Lichfield UK 400m from a major supermarket school hospital and very busy roads.
These new dongle type SNAs and SDRs have revolutionised radio astronomy bringing it within reach of everyone.
One piece of software that I would highly recommend is ezRA suite written in Python by Ted Cline of SARA (Society of Amateur Radio Astonomers in USA). It is amazing free and Ted is so supportive as is whole SARA membership even if you are not a member, as I discovered!
If you look at my website you can see the incredible plots it produces. It will collect analyse plot data, and then place it against galactic background of known sources and Milky Way, and work out Doppler shift and give you a basic interpretation of that shift all for few clicks of the mouse!
Andy
Your plots are improving. 86 cm is not too bad. I wanted a 3m dish too, but it was just too expensive. 😫 Even the MIT student dish is only 1.8 m.
My 1.3 m dish was a fiver off ebay, which seemed like a deal.
1.22 x 21cm/86cm is about .3 Radians or 17 degrees. That's the resolution of your scan. You can see how @ZiHao has widened his antenna with struts and wire. You could do the same.
Good luck,
Steve.
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9 hours ago, bosun21 said:
This thread has put me off from buying an EQ6 in the future for sure. Do the motherboards have a vulnerability that the other SW mounts don't?
I have an eq6 that works perfectly. I did change the handset once, I think with Malc here, but I also had problems from time to time with my eq5 and an eq3. All electronics go wrong from time to time, especially if they're left outside in an observatory. But the eq6 is the best mount I've ever had. I have no plans to change it.
Steve.
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Nice. The top left image has three peaks. A tall one and two short ones. Like this:
Each peak is a separate arm of the Milky Way, so three arms. You can calculate the distance to each one.
Here the writer has performed a gaussian fit on each peak to find the central point.
As the Earth spins you can collect a plot, say, every 10 minutes and plot the curve for each spiral arm.
Here's how to do it.
https://physicsopenlab.org/2020/09/08/measurement-of-the-milky-way-rotation/
Good luck.
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There are several resources:
With a writeup here:
https://www.rtl-sdr.com/pictor-an-open-source-low-cost-radio-telescope-based-on-rtl-sdr
Managed by one of our members.
rtl-sdr.com has lots of other references too. Eg jobs telescope (Google it).
@Victor Boesen also has written some sdr code on github, which works quite nicely and I used his with a 1.3 m dish and sdr.
From where we are you can map at least 1/4 of the Milky Way. If you have a clear horizon maybe more. Prepare to be stunned at what you can do 😀
Good luck,
Steve.
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On 07/08/2023 at 20:26, Victor Boesen said:
That's excellent. Job has done a large variety of interesting things in the amateur radio astronomy community! I did something similar myself a couple years ago, albeit with some more modest equipment due to my current life situation
My setup consisted of a simple wifi grid antenna I bought on ebay, together with a dedicated LNA and an RTL-SDR.
Here are the observations I used to determine the rotational velocity from, showing the change in dopplershift across the galactic plane.
And finally, my achieved results below.
The blue dots represent the initial results, whereas the red results were corrected to the barycenter, ie. with the orbital velocity of the Earth taken into account.
It's always fascinating to see what Job achieves with his amateur equipment, and it's very fun to push the limits - just like in astrophotography!
Victor
Nice Victor. I didn't know you had gone on to do this. Good job.
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Hi Astronomers,
Does anyone know where I can find the spectroscopic data for galaxy rotation curves for M31, M81 and M109 (and maybe others). There are plenty of curves that can be cut and paste, but actually, I'd like to regenerate them. Like these:
M81
M109
M31
But without all the other lines. I had hoped that places like Simbad might have them, but I can't really work out how to use it.
Kind regards,
Steve.
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On 05/06/2023 at 00:05, robin_astro said:
It is more common to mount them in a circle to give even illumination independent of the orientation relative to the direction of the slit. A nice setup suggested by Christian Buil with his StarEx is to feed optical fibres to small clips round the edge. The obstruction is small and they can be left mounted without significantly disturbing the telescope throughput. They can even be switched on during the exposure to superimpose lines on the spectra giving very high precision calibration for example where flexure might be an issue during long exposures.
https://groups.io/g/Solex-project/topic/88905429
(In French but the photos tell the story and Google etc translates well if you need more information)
Cheers
Robin
Yes, it hasn't been ideal, I might try that.
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8 hours ago, SteveBz said:
The Alpy is a nice spectrometer
I'm just going to add to that, it needs the guide module to keep the star on the slit.
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3 minutes ago, Gasman said:
Hi peeps
Forgive me if slightly off topic🤞. I've been out of the astro game for a few years and considering a return. I last was mad keen on spectro, I still have all my gear and have my little Alpy 600 sat quietly on a shelf. As another hobby of mine is 3d printing and wondering if I have anything to gain by printing/using a Lowspec over my Alpy please?. I'll have to dust off my spectro books as I'm a little rusty with it👍.
Thanks
Steve
The Alpy is a nice spectrometer. I'd get that going first and then try others. The LowSpec I use is 1800 lpmm and your Alpy is 600. There's little point in switching unless you want finer resolution.
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Just FYI. In the end I didn't print this myself. It was probably @SSI-Rick and he lent it to me.
Anyone running KStars/Ekos/Indi on a Raspberry Pi 5 with RPi OS bookworm?
in Discussions - Software
Posted
So I used nou's script here for the first 3.
https://gitea.nouspiro.space/nou/astro-soft-build
Which works perfectly.
What did you use for PHD2?
Kind regards
Steve