Jkulin

Hi, your videos are coming up with the following, perhaps it is a permission issue: -

Thanks David, yep I plan to leave 3 lengths in there just in case

5 minutes ago, carastro said:

If any of this is going be exposed and got at by rodents then I'd get armoured cable. 

Carole 

Thanks Carole, nah it will all be underground in 3" piping

Hi All,

My builder is coming over this weekend to prepare to pour the concrete on Monday and I completely forgot to order mains cable.

I need to order it quickly so can anyone advise what cable I will need to run the main through the conduit underground.

It is going to just plug into the 240v outdoor waterproof plug in the lean to.

At the moment I run 12v cabling out to the pier, the plan is to have sockets in the dome to power the PC, Humidifier and all the peripherals.

The run will be around 35 metres.

Can anyone advise please?

Many Thanks.

I used to live in Stoneleigh, Worcester Park and Ewell, so I do sympathise with you about your skies.

When you visit a true dark sky it will blow your mind, so take your time to find the right place, if I could and didn’t have family, then I would move to a Bortle 3/4.

Good luck.

Thanks Geof, I think I'm sorted for this week, but will put M53 on the list for the next object after this session. M5 is always a problem with it being low behind the trees for me, so I doubt I will be able to grab that from my location.

Thanks Geof, I only grabbed that as a second thought, I've done M13 and M92 and from my location there aren't many I can image otherwise, so now what to capture over the next 4 nights?

This was just a very quick session as we won't have any true Astro darkness for a couple of months.

I was unsure what I was going to do and then saw that M3 was ideally placed for me to grab a few hours as I didn't want to waste the lack of the moon.

I have reprocessed this about 3 times as I knew there was some nice gentle star colour, hopefully I have respected that they aren't strong but subtle colours.

Capture details: -

10" GSO/Altair RC Truss, Moravian G2-8300 Mk!!, iOptron 120EC Mount, Ultrastar Guide Camera, Chroma 2" Filters, QHY OAG. Processed in PI and PS 2020

Chroma Blue 2" unmounted: 8x390" -20C bin 1x1
Chroma Green 2" unmounted: 8x300" -20C bin 1x1
Chroma Luminance 2" unmounted: 11x300" -20C bin 1x1
Chroma Red 2" unmounted: 8x348" -20C bin 1x1

Further details here: - https://www.astrobin.com/7z8grc/

Anyway, here's the bumf: -

Messier 3 (M3 or NGC 5272) is a globular cluster of stars in the northern constellation of Canes Venatici. It was discovered on May 3, 1764, and was the first Messier object to be discovered by Charles Messier himself. Messier originally mistook the object for a nebula without stars. This mistake was corrected after the stars were resolved by William Herschel around 1784. Since then, it has become one of the best-studied globular clusters. Identification of the cluster's unusually large variable star population was begun in 1913 by American astronomer Solon Irving Bailey and new variable members continue to be identified up through 2004.

Many amateur astronomers consider it one of the finest northern globular clusters, following only Messier 13. M3 has an apparent magnitude of 6.2, making it a difficult naked eye target even with dark conditions. With a moderate-sized telescope, the cluster is fully defined. It can be a challenge to locate through the technique of star hopping, but can be found by looking almost exactly halfway along an imaginary line connecting the bright star Arcturus to Cor Caroli. Using a telescope with a 25 cm (9.8 in) aperture, the cluster has a bright core with a diameter of about 6 arcminutes and spans a total of 12 arcminutes.

This cluster is one of the largest and brightest, and is made up of around 500,000 stars. It is estimated to be 11.4 billion years old. It is located at a distance of about 33,900 light-years away from Earth.

Messier 3 is located 31.6 kly (9.7 kpc) above the Galactic plane and roughly 38.8 kly (11.9 kpc) from the center of the Milky Way. It contains 274 known variable stars; by far the highest number found in any globular cluster. These include 133 RR Lyrae variables, of which about a third display the Blazhko effect of long-period modulation.

The overall abundance of elements other than hydrogen and helium, what astronomers term the metallicity, is in the range of –1.34 to –1.50 dex. This value gives the logarithm of the abundance relative to the Sun; the actual proportion is 3.2–4.6% of the solar abundance. Messier 3 is the prototype for the Oosterhoff type I cluster, which is considered "metal-rich". That is, for a globular cluster, Messier 3 has a relatively high abundance of heavier elements.

https://en.wikipedia.org/wiki/Messier_3

3 hours ago, teoria_del_big_bang said:

The add also says they ship direct to customer from China.

In actual fact it probably is a pretty decent printer, after all most arts of any other printer comes out of China originally. 

But not much good for a first printer when they state:

But, it is a pricey item and unlikely to get past customs without them charging duty and also post office then charge their bit for some paperwork. At the end of it you have a reasonable printer but probably no after sales service, no chance of returning without a great deal of hassle and after the customs get their bit not that much cheaper than a genuine Prusa with excellent after sales.

Many good printers out there for similar price without buying direct from China, Creality also great printers but many others.

Steve

Thanks Steve, Much appreciated, yep I'm to hang fire until I have enough to put together for either a Prusa or Similar quality with good support as I fear I will need it.🤪😀

10 minutes ago, bob-c said:

This is a faint one John, don't think I will try this a bit beyond my capabilities. Well done on bringing this one out.

Bob.

Cheers Bob, with better skies I know I could get a lot better, but with Bortle5/6 its the best I could get.

4 hours ago, Peter Drew said:

At least you knew who I was referring to.   🙂

There's only one, watched him from when he won his first 125GP

13 minutes ago, Peter Drew said:

Unlikely I think but the similarity is there.     🙂

I think Valentino would not be quite as subtle though 😁

5 hours ago, Peter Drew said:

Named after a famous MotoGP rider?     🙂

Is that true Peter, I bow to your far superior knowledge!

1 hour ago, geoflewis said:

I'm curious about some of your sub exposure lengths, e.g 390s, 348s. Other than for very short exposures I always shoot in 1m intervals above 2m. In particular 348s is a very precise choice, so how did you arrive at that rather than say 360s (6m). I restrict my exposure lengths according to the dark library that I maintain, so typically 30s, 1m, 2m, 5m, 10m, 15m - that's probably me being lazy, but I'm interested in the reasons for your choices.

Hi Geof, Thanks for the comments.

Peter Shah put me onto G2V Star Calibration a few years ago and I think it has helped, the video below explains things better, but essentially you find a star that matches a similar colour to our Sun, then take a number of exposures, I usually test between 0.5, 1, 2, 3 secs and then analyse the star for each RGB filter, it needs to be from an un-saturated image , then using the green as the base you compare the red and the blue, I use Pixinsight, that will then allow me to work out a ratio.

Your supposed to do it on a regular basis, some say even each session, I don't get enough clear night to change, but may well do it during the shorter nights, you need to do it for each OTA, Camera, Filter combination.

@carastro Thanks Carole, Yes when I captured the first test sub in SGP I could see nothing and really did wonder if my platesolving had failed, but after checking and stretching the hell out of the test image I could see a faint crescent, this was the first stack of 11 x 1200s of the Ha and OIII, you could see nothing with the RGB: -

and this was 3 of the OIII: -

@Whirlwind Thanks for the explanation and clarification, I should have checked my info before posting, but it was late and I never assumed it would be incorrect, thanks once again.👍

I have been enjoying the challenge of capturing and processing planetary nebula, I'm not sure I can do the beauty of them real justice, I learned many new techniques, a good number I need to develop on. This one really was feint.

I had planned to try and get 30 hours of data, but having just added it up to 16 hours I don't think the extra would improve things with my light polluted skies.

I captured this over the 13/14/15/16/20/21 May 2020

Captured with my GSO/Altair 10" RC Truss, Moravian G2-8300, iOptron 120EC, Pegasus focuser and UPB, Chroma 3nm 2" Filters

Chroma Blue 2" unmounted: 8x390" -20C bin 1x1
Chroma Green 2" unmounted: 8x300" -20C bin 1x1
Chroma Ha 3nm: 22x1200" -20C bin 1x1
Chroma OIII 3nm: 19x1200" -20C bin 1x1
Chroma Red 2" unmounted: 8x348" -20C bin 1x1

More details here: - https://www.astrobin.com/lw3re6/

Information on Sh2-174 is scarce, but I have managed to grab exerts that I have put together for some background information: -

Sh2 -174 is a planetary nebula visible in the constellation of Cepheus

A strange nebula in deep space shines like a cosmic rose unveiled just in time for a past Valentine's Day.

It is one of the northernmost planetary nebulae of the celestial vault; it is located about 3 ° north of Alrai , the γ Cephei and is visible in long exposure photos. Its strongly northern declination means that it can be observed almost exclusively from the northern hemisphere , where, on the other hand, it is circumpolar up to the tropical latitudes.

A planetary nebula is one of the last stages of life for most mid-sized stars. Once a star runs out of fuel, it begins to collapse in on itself, creating the clouds of red and blue in the photo.

As the star sheds layers, it forms into a white dwarf — a densely packed star that has the mass of the sun, but is stuffed into a volume about the size of the Earth.

Usually the white dwarf can be found very near the centre of the planetary nebula, but in the case of Sh2-174 it is off to the right.

The white dwarf star appears as a very blue star in the centre of the blue region of gas in the new image. The off-kilter star arrangement is likely the result of interactions between the nebula and its surroundings.

The cloud, catalogued as a generic emission nebula in the sixties , never showed signs of star formation in progress, nor was the ionizing star of its gases known ; during the nineties the hypothesis was put forward that it was a planetary nebula, the central star of which over time slipped out of the gaseous envelope created by itself, since its dimensions were too small to be an H II region , but comparable to those of a normal planetary nebula. This ionizing star would be the white dwarf catalogued as GD 561, placed outside the cloud. The distance, from which the dimensions were derived, was obtained by studying the radial velocity , and is indicated around 300 parsecs (about 980 light years).

4 hours ago, tooth_dr said:

Nice improvisation 👍🏼 Unfortunately it’s not the filters but the scope in my case. 

That's what I am saying Adam, to work out the backlash of the scope sandwich a piece of paper between the focuser tube and the body and very slowly ease the focuser out until it lets the paper drop, take the measurement and that is your backlash for the scope, then when you input your focuser backlash you then have the figure.

Don't worry what I said about the filters, that was just a passing comment.

On 16/05/2020 at 11:38, tingting44 said:

Just come across an interesting watch, this guy uses huge samples, and only samples the outside of his image, kind of makes sense, I'll have to experiment to see for my self but he seems to get good results...

 

 

Shauns videos are really helpful and he a nice relaxed way of explaining without a load of waffle

11 hours ago, Adreneline said:

I still think this series of tutorials is very helpful with a good balance between telling you what to do and why you are doing it.

There is also this new book/ebook which I am getting to like a lot.

Food for thought.

HTH

Adrian

 

 

 

Yep, I learned from lightvortex, highly recommended👍🏻

Hi Adam, I used to use a piece of paper held into the focuser body and on a table I would slowly back the focuser out until the paper fell to the floor, that was my back lash figure, I don't worry any more as the Chromo's are all par-focal

Hi, Your flats aren't working as there appears to be dust bunnies/artefacts present in the image.

Had a quick dabble but would suggest that you need a shed load more data, at least 7-10 hours of data.

Did you do flats as there was some serious gradients and artifacts, I couldn't push the noise reduction much further because there just wasn't enough data: -

4 hours ago, kirkster501 said:

I have looked at building an inverter into my box too but I am looking for a 12v flats panel to remove the need to do so.  My current flats panel is the only thing that needs a mains input.

Hi Steve, I have a similar one for larger flats and the 12" version for my Esprits: -

Voilamart A2 Light Box Drawing 12V LED Tracing Board with 3 Level Brightness Ultra-Thin Artist Copy Board Micro Artcraft Animation Light Drawing Pad

More information: https://www.amazon.co.uk/dp/B07VK2GLWV/ref=cm_sw_em_r_mt_dp_U_C2gWEbMMWWJMR

I'm just uploading to Astrometry.net and I'll post the results when it has updated for you.

Here you go: -

4 hours ago, tooth_dr said:

Hi John. Nothing arrived yet. 

Sorry Adam, I hadn't hit the send button, you should have it now.

Just PM'd it to you Adam,