IC1318, the Sadr region lies at the centre of the Cygnus constellation, close to the central star Sadr or Gamma Cygni – it contains many dark nebulae as well as diffuse emission nebulae. I chose to image this region as the contrast between light emission and dark areas are quite pronounced and a lot of detail can be easily discerned.
However the amount of detail captured is very poor when imaged with an OIII filter, so I only used Ha and SII filters and combined them by putting the Ha data into the green channel and the SII data into both the red and blue channels in Photoshop to create the following SHS ( SII, Ha, SII ) colour image, also some tweaking of the contrast and highlights ( this is commonly known as messing about ).
Captured over two nights with an Altair Astro 8inch RC, Baader Ha and SII narrowband filters and a ZWO asi1600mm Pro mono camera, 40 x 300 seconds exposures with both filters.
below is a wider view, captured usinga 72mm William Optics Megrez refractor and the same filters and camera.
In my earler post, I said that I had set up my Canon EOS 600D DSLR camera some weeks ago to try and capture some Eta Aquarid meteors, now while I had transferred the image of Venus that I had taken, I had not looked at the rest of the images stored in the camera from that evening ( 21st April 2020 8.30pm ) – I had a look today and though I had not captured any meteors I did it seems, by chance capture these bleeding Starlink satellites. I had pointed the camera at an area of sky just below Ursa Major, the Great Bear, the Plough or if you prefer the Big Dipper, I had started to capture images just before 8.30pm and the sequence of 59 images that contain the satellites trails go on for 6 minutes, I had to adjust the tone of the individual images in Photoshop to make the trails stand out better, then reduced images to a quarter original size to allow me to make a GIF.
Below is a single image from the sequence, I have marked where the satellite trails are as its hard to see without enhancement.
Here’s the GIF of the Starlink pass, you can see the stars of the big dipper handle as well as some whispy clouds.
As these images were captured at dusk, you can see how bright they would of been had it been properly dark.
The Crescent nebula, NGC 6888, Caldwell 27 orSharpless 105 is an emission nebula in the constellation of Cygnus, that is some 5000 Ly away, formed by the stellar wind from WR136, a Wolf Rayet star – colliding with and energizing the slower moving wind ejected by the star when it became a red giant around 250,000 to 400,000 years ago.
Here is a spectrum of WR136 that I previously captured, note the bright emission lines.
I decided to image this object as I already had data in Ha, OIII and SII, as long as your using the same set up, telescope, field flattener and camera, you can keep adding to the data, that’s the beauty of digital imaging, I added an extra 4 hours of exposure to the data and came up with this image.
As I mentioned in yesterdays post, I was going to try and capture these Starlink satellites with my allsky camera, they would pass over this morning at 3.48am GMT, the following comes from the Express website.
Space enthusiasts will be treated to two opportunities to spot the synthetic satellites this week, according to the Find Starlink website.
Wednesday, May 27 at 3.48am GMT: Starlink-6,7 will be visible travelling from southwest to east for around five minutes.
This starts at 13° from the horizon and the constellation will reach a maximum elevation of 51°.
Thursday, May 28 at 2.50am GMT: You have a second chance of spotting Starlink-6,7 while traverses from south to east for approximately three minutes, starting at an elevation of 25° and reaching 29°.
Well the allsky camera caught nothing. the problem lies with the information re-produced by the express science collumist, Tom Fish, who starts his post with the headline.
SpaceX Starlink: These are the exact dates and times to see Starlink from the UK this week
He reported the times in GMT ( Greenwich Mean Time ), the findstarlink.com website clearly states all times are in BST ( British Summer Time ) which is one hour ahead of GMT, so I was an hour late, now I challenge Tom Fish to see any satellite, unless it’s burning up in the atmosphere, at 17 minutes before sunrise.
I should of checked the findstarlink web site myself, lesson learned – tomorrow morning at 2.50am BST looks a better option.
Here is an image of Venus from my backyard taken 3 weeks ago, I had my Canon EOS 600D on a timer hoping to capture some Eta Aquarid meteors so I took a quick shot of the planet before it started getting too low.
The days are long and the nights are short, at the moment there are about 4 hours of usable darkness for Deepsky imaging, fortunately since most of the aircraft have been grounded due to the Covid 19 pandemic, the skys have been much much clearer, this has happened before, I refer you to a previous post of mine about when the Icelandic volcano Eyjafjallajökull, erupted in April 2010, I’m even more convinced now that aircraft emmisions are the cause of so much bad weather and a huge contributor to global warming ( Aircraft operators can plant as many trees as they like, trees will not clean air 31000 to 38000 feet up ). Anyway back to topic, I have booked a weeks holiday to enjoy the weather, not going anywhere just relaxing at home and taking advantage of the clear ( night ) sky, I have done more imaging in the last two nights than i have for a long time, a total of 8 hours gathering narrowband data on IC1396 the Elephants Trunk Nebula in Cepheus, this was added to data that was captured in 2018 giving about 16 hours of exposure.
I must confess, I would have done some imaging a couple of weeks ago – but I had a moment where I seriously considered giving up astro imaging altogether, a couple of weeks ago I happened to be standing in the back garden looking up, when I noticed a satellite passing from west to east, ( nothing odd about this there are roughly 5000 in orbit, under 2000 of those are operational ) then another 30 seconds later following the same path, then another 30 seconds after that and so it went for about fifteen minutes, what I had seen was part of Elon Musks, SpaceX, Starlink satellite constellation, these satellites – when they cross the field of view of a telescope and camera, leave lines in the image as they pass.
I phoned a friend of mine, another amateur astronomer to have a look himself, we both agreed it was a sickening thing to see, many non astronomers do not realise the danger to our night sky these things pose, especially as they are already having an impact on the night sky with only 360 them, Mr Musk ( the very same guy who thought it a good idea, albeit an egotistical one to launch a Tesla Roadster, complete with a spacesuit clad dummy into space, from an astronomers point of view he would make an excellent Bond villain ) wants to launch 30,000 of them, to provide global broadband internet coverage.
By the year 2025 SpaceX plan to have 12,000 Starlinks in orbit distributed as follows
7,500 at 340 km altitude
1,600 at 550 km altitude
5,800 at 710 km altitude, data courtesy of Union of Concerned Scientists.
But thats not all, there are other companys that want to launch their own satellite constellations, OneWeb with an initial 800 satellites, Amazon last year announced project Kuiper, with 30,000 satellites and Canadian company Telesat wish to do the same, although they have not as yet said how many satellites they will have.
I set my allsky camera up to see if I could capture some of these rudy things, but all I got was the ISS, at least when you see that, you can think to yourself, there’s people up there, the StarSTINK ( thanks for the name Ron ) satellites should pass over the UK on Wednesday, May 27 at 3.48am GMT, I’ll try again then.
The allsky camera works using software to compare one image with the next, any change such as a satellite or meteor triggers a capture sequence, imagine what it will be like when the sky is a moving net of satellites, it will be running a continuous capture sequence.
The issue of trails on deepsky images can be fixed with stacking software and Kappa Sigma Clipping algorithms, which ignore outliers such as satellite trails ( yet to be tested on a stack of badly trailed images ) and cosmic ray action on a camera sensor, but if you just want to lay back and look up at the spendour of the night sky, especially if you live under a dark non light polluted sky – then your view will be spoilt beyond doubt.
That was why I was ready to give up the ghost, I do like to just stare up at the beauty of the heavens from time to time, is it’s not enough that we pollute the earth for greed, we now need to pollute the night sky as well.
A clear Saturday night ( shame about the moon ) had me gazing at a comet, this comet was discovered by the ATLAS ( Astronomers do love their acronyms – this one stands for, Asteroid Terrestrial-impact Last Alert System ) survey on December 28, 2019, and it was thought that it might reach naked eye brightness, however on around the 2nd April 2020 the comet underwent a fragmentation event, having thought to have split into at least four pieces, possibly due to outgasing causing an increase in centrifugal spin, this has caused the comet to dim considerably, however it does have a 3.3 million km long tail, more than twice the diameter of the sun.
Updating the comet elements in Cartes du Ciel ( CDC ) meant that once I had done a single star alignment and a quick plate solve of the star field, the telescope then slewed directly to the comet and put it squarely in the middle of the camera sensor, a hell of a lot easier than following a printed star chart and star hopping to the object.
I captured 43 x 120 second exposures through the 8 inch RC and ZWO asi1600mm using a Baader 2 inch clear filter, the moon being three days from full – together with a bright sky glow did give some hard gradients, that were difficult to process out entirely.
Capturing so many images meant I could turn the images into a GIF to show the movement of the comet against the background stars. My appologies for the jump in the GIF, I had a go at tracking the comet instead of a star in PHD2 , I was hoping to get a clearer look at the tail, however the comet nucleus was too faint to keep a good lock on it, so I had to revert to star tracking.
Whether this comet holds together enough to brighten again as it approaches the sun, remains to be seen ( no pun intended ).
Wow, almost a week of clear skies – and is more than typical I have had a few early 4 am starts, I drive a Cement mixer so I had to choose between imaging and sleep ( The UK Government has allowed construction work to continue, even though Social Distancing is near imposible in construction, therefore I have not self isolated at home and have had to go to work as the spread of the Covid 19 virus continues apace ). The good news is Friday night was clear so I managed to capture another part of the Rosette nebula mosaic project I’m working on, 26 x 180 seconds exposures in Hydrogen Alpha were used to create this image.
This was combined with the other 3 panes of the mosaic, this will probably be the last addition to this Rosette project till later in the year when the nebula reappears, it is getting darker later and the object lower in the sky, that’s why I only managed to capture 26 images to stack together.
Keep well and stay safe, everyone.
Something not astro imaging related
Some info on Social Distancing from the Government.
Only go outside for food, health reasons or work (but only if you cannot work from home)
If you go out, stay 2 metres (6ft) away from other people at all times
Wash your hands as soon as you get home
Do not meet others, even friends or family.
You can spread the virus even if you don’t have symptoms.
Coronaviruses can be spread when people with the virus have close, sustained contact with people who are not infected. This typically means spending more than 15 minutes within two metres of an infected person, such as talking to someone for instance.
The more you come into contact with the droplets from coughs and sneezes of an infected person, the more likely you are to catch the infection. This is why we ask people who have the infection to self-isolate at home and not to go out and about where they can pass it on.
However, on its own self-isolation may not be enough to slow the spread of a virus.
The Government’s new Coronavirus action plan recognises that as we start to see more cases in the UK, and more widespread community transmission of the virus, further measures to reduce the contact people have with each other may be needed.
These measures, sometimes referred to as “social distancing”, could include things like temporarily reducing socialising in public places such as entertainment or sports events, reducing our use of non-essential public transport or recommending more home working.
Social distancing isn’t a new idea that’s come about because of coronavirus. These measures are well-established and have been discussed and planned for many years, including as part of the Government’s preparations for a flu pandemic.
I’ve worked in construction and not every task on a building site can be carried out by one man, but it’s not only construction, two or three man Recycling and Refuse collection teams travel to and from their ” Rounds ” sat in the front of the collection vehicle.
A rare clear Sunday night, coupled with an even rarer Monday off gave me the opportunity to image M81, in the Constellation Ursa Major, also called Bode’s galaxy after Johann Elert Bode who discovered it in 1774. It is a grand design spiral galaxy about 12 million LY’s away, with a diameter of about 90,000 LY’s. I have imaged this object with a 10 inch Newtonian telescope and a DSLR back in 2016.
I imaged it last night through my 8 inch RC and the asi1600mm Pro monochrome camera using a Neodymium filter thats cuts out UV, and reduces star bloating. I captured 26 x 300 second exposures and processed them through Deepsky Stacker and Photoshop.
I then combined this image with the one from 2016 to produce a clearer colour image.
The Rosette nebula is now too low down now to image it until later in the year when it comes back round again, however the galaxy imaging season is here.
The Corona virus ( COVID 19 ) has finally had an effect on the astronomy community, the monthly meetings held by the Somerset Levels Stargazers has been cancelled until further notice, this is understandable as quite a large percentage of the members are of the older age group, I have no doubts that the meeting for the Crewkerne and district Astronomical Society will have a similar announcement very shortly. On a positive note the cancellation of so many international flights can only have a positive effect on climate change and hopefully produce some clear night skies.
Another three weeks have gone past, with only a few hours of broken clear ( ish ) sky, but nothing I could work with as the wind has been a constant companion. Guiding under such conditions is a waste of time, the telescope gets buffeted around too much – not helped by yet another storm, this time called Jorge ( pronounced “hor-hay” ) named by the Spanish met office, bringing with it snow, ice, strong winds and pummeling rain. This makes the wettest February on record with an average of 202mm of rain.
The 7 day forecast does not really look great either with more rain for tomorrow, makes you wonder why anyone would bother with astronomy and especially astroimaging in this country, the last 12 months have not been particularly good, with about 14 imaging sessions in total. I’m looking forward to going to a monthly club meeting and being able to show some images again, when though, that’s another matter.
I have made no more progress towards completing the Ha, 8 pane mosaic of the Rosette nebula, NGC 2237 – around 20 days have passed since I put together 3 panes of the mosaic, since then the weather has been against me. Last weekend here in the UK, we had storm Ciara – that battered the whole country with wind gusts of up to 80mph, bringing yet more flooding to parts of the country already suffering from floods, and now this weekend brings storm Dennis to take over from where Ciara left off.
The way the weather is going it will be November 2020, before I get the chance to do any more work on NGC 2237, soon the object will be too low down by the time it gets dark, in all I need 36 hours of exposure time to complete the project, 6 clear nights of 6 hours imaging time, is that really too much to expect, I suppose it is with the UK weather, this brings me onto the subject of astrophotography competitions, recently a friend of mine , Ron – suggested I enter some of my images into the BBC’s Sky at night magazine, Insight Investment Astronomy Photographer of the Year 2020 competition, entrants are from all over the world and the overall winner will recieve £10,000 with £1,500 being awarded to winners of individual catagories, I can enter 10 images taken after 1st January 2019, I have gone through my images and only 2 completed images ( taken after 1st January 2019 ) that I consider good enough can be entered, so fingers crossed but I think that imaging from the UK is a bit of a handicap, 10 completed images in a year, what a luxury.
A few days ago we had a spate of clear nights ( sort of ), this gave me the chance to image the Rosette nebula in Monoceros. Now I have imaged this object before, but that was with a small telescope, a 72mm William Optics Megrez refractor – this time I wanted to image this nebula and open cluster NGC 2244 ( the stars of which is formed from this molecular cloud ) with my 8 inch RC telescope for more detail. This rig has a higher magnification and therefore a smaller field of view, this means I cannot get the whole nebula onto the camera sensor, so I have to image several sections ( slightly overlapped ) and put them together as a Mosaic.
I will need 8 images to make this mosaic to cover the whole gas cloud, each image will be made from 30 light frames, each of 3 minutes exposure. I also want to image using the Ha, OIII and SII filters. so lets work this out, 8 mosaic panes x 30 light frames x 3 filters = 720 light frames at 3 minutes exposure = 36 hours total imaging time, obviously more than can be done in a single imaging run, infact if I get 6 hours of clear imaging a night, that’s 6 nights work. 6 clear nights would be a luxury the way things are with the weather at the moment, thank heavens the images are digital and can be saved.
As it stands – the spate of clear nights only gave me 2 usable nights, the remaining nights were misty and foggy, sadly sunny days on wet ground lead to misty foggy evenings.
so I have out of the 2 usable nights, 3 mosaic panes of the Rosette nebula in Ha – this definitely going to be a work in progress.