Sunday, 19 January 2020

Ha Full Disk & S6348 - 19th January

With each passing day the sun gets higher and higher in the sky, and with seasonally high pressure sat over the UK this weekend allowed an opportunity to get a view of our star,  It will only be a couple of weeks until the sun is clear of of my winter tree lined horizon.  Till then it is a case of grabbing the gaps between the trees, and this Sunday afternoon allowed just that.  The sun seems at first glance blank, but in the north east quadrant a emerging flux region shows itself as a bright point, and is likely to develop as an active region as is already showing pores in white light.  Polar filaments in the northern hemisphere are already a proxy of cycle 25, and on the south western limb a flame prominence was very evident.  The disk was taken with a Lunt 50 etalon on a 60mm f6 scope, double stacked with a Daystar Quark and imaged using a GH3 camera.

Tuesday, 14 January 2020

More Cycle 25 Activity - 14th January

Check out this animation, showing activity from the SDO AIA304 channel. Look at the 10 o'clock position how a small emerging flux region develops. Given the latitude my money is on it being cycle 25...

Thursday, 9 January 2020

Development of AR12756(?) - 9th January

Cycle 25 activity seems to becoming more prevalent, and over the last 24 hours or so, and in the north western quadrant of the sun an emerging flux region soon developed into an active region (AR12756?).  This animation from the AIA1600 data shows the spot formation quite well.  

Sunday, 5 January 2020

Something About to Round The Limb? 5th January

Noticed on the STEREO animation from today looks like something is going to round the limb fairly soon. It's currently at -100 or so longitude, and it's equatorial position suggests cycle 24. You can see something in the field lines in the corona in the AIA171 image too at the inferred position.

Keep your eyes peeled folks, we may have another sunspot...

Saturday, 4 January 2020

AR12755 4th January

AR12755 from cycle 25 is still visible as an active region with sunspot but activity is declining, as the main spot can seen to be divided by a light bridge, which is a usual indicator of decay.  This image is from the Solar Dynamics Observatory, but for amateurs it is still visible as a bright area in Hydrogen Alpha, and the plage will remain visible in CaK light for many days to come.

Wednesday, 1 January 2020

New Year, New Solar Cycle, New Sunspot (again!) - 1st January

2020 is upon us, and as the world wakes to a new decade, we also wake up to a new sunspot from cycle 25, no sooner had AR12753 faded this new sunspot rounded the limb in the solar southern hemisphere.  Given the southern hemisphere has this activity first, it will be interesting to see what the lag with the northern hemisphere following will be, this also leads to the likely possibility of cycle 25 being double peaked as cycle 24 was.  This asymmetry on average could numerically result in solar cycles on paper being weaker, however if both hemispherical peaks coincided this would result in the solar cycle again being numerically stronger.  We will have to see over the coming years as to how this all pans out.

Tuesday, 31 December 2019

Ha Full Disk 30th December 2019

This is my last solar image of the decade; clear skies on monday meant I was able to make the most of the small gaps in the trees to get a chance of seeing the sun.  Cycle 25 active region AR12753 is still visible as a patch of bright plage, but all sunspots have now receded.  A few small prominences and few ephemeral bright points are the only other things visible but as we move into 2020 activity is set to rise.  This image was taken with the Lunt50 etalon on the ED60 f6 scope, double stacked with a Daystar Quark, a Baader solar telecompressor was used along with the PGR camera.

Thursday, 26 December 2019

Christmas 2019 - When Solar Cycle 25 Woke Up

The information from Solen says it all; on Christmas day I was able to observe the 2 active regions visually using a Daystar Quark where they were easily visible.  The chart above shows the magnetic signatures of cycle 25 are getting more prevalent.  Poor weather is forecast for me for the rest of the year so unlikely I will get to image or view until 2020, either way next year should be an exciting time for all things solar!

Tuesday, 24 December 2019

Christmas Sunspots From Cycle 25 - 24th December

Christmas Eve has brought not just one sunspot grouping from cycle 25, but two! We know this from their reversed polarity compared to cycle 24 spots.  There have been a number of small single spots and pores earlier this year, but so far this is the most cycle 25 activity we have seen.  Fingers crossed this is setting up 2020 as being a good year for solar astronomy as more features become visible.

Wednesday, 11 December 2019

Solar Cycle 25 Forecast Update

published: Monday, December 09, 2019 22:30 UTC

The NOAA/NASA co-chaired, international panel to forecast Solar Cycle 25 released their latest forecast for Solar Cycle 25. The forecast consensus: a peak in July, 2025 (+/- 8 months), with a smoothed sunspot number (SSN) of 115. The panel agreed that Cycle 25 will be average in intensity and similar to Cycle 24.

Additionally, the panel concurred that solar minimum between Cycles 24 and 25 will occur in April, 2020 (+/- 6 months). If the solar minimum prediction is correct, this would make Solar Cycle 24 the 7th longest on record (11.4 years).

Thursday, 14 November 2019

Mercury Transit - 11th November

Monday was the transit of Mercury over the face of the sun, sadly I was at work at the time and observing it really wasn't an option unfortunately.  Fortunately these days there are so many live sources of our star online that at various points I was able to get a virtual view of the transit.  Here is the AIA1700 image from the Solar Dynamics Observatory I grabbed that shows Mercury as the small black disk nearly dead centre on the sun.  The next doesn't occur until 2032, maybe I will be fortunate enough to have retired by then and will be able to observe it.

Sunday, 27 October 2019

Iceland Sunrise - 27th October

The light at sunrise was simply amazing this morning here in Iceland!  Twilight lasts for 2 hours at this latitude this time of the year, and so it was a pleasure to watch the changing hues over time!

Iceland Sunset Aurora - 26th October

Following 2 days of auroral storms, the solar wind was still flowing in excess of 600km/s, which is pretty fast.  As a result as soon as it started to go dark there were aurora visible here in Iceland.  This animation spans 30 minutes from sunset and was taken with a Canon 350D, Sigma 10mm f4 lens, 20s exposure at iso 800.  The aurora were visible for the whole of the night and were lovely to see again!

Monday, 21 October 2019

CaK Full Disk 19th October

The seeing conditions weren't great when I imaged my full disk in Ha, but the passing of a weather front meant the air was very transparent and so I had some hope for calcium imaging.  I used the ED80 stopped down to 60mm along with the homebrew CaK filter.  Looking at the enlarged image it is possible to see the spicule ring around the edge of the sun, along with faint prominences.  Looking at the centre of the disk it is possible to see the inverse granulation that characterises the view in Calcium light.

Ha Full Disk 19th October

Poor weather has meant it's seemed like an age since I was able to do any solar observing, Saturday arrived and despite the sun being blank I decided to get the scopes out and observe.  The northern polar regions were the most interesting with a hedgerow like filament and bright points corresponding to polar faculae.  Taken with a Lunt50 etalon on the ED60 that was double stacked with a Daystar Quark.

Sunday, 8 September 2019

45 Minutes in the life of a Quiescent Prominence - 8th September

Lovely clear blue skies this morning, only a couple of degrees above zero at dawn, won't be long till we have a frost I think... The sun was completely blank, nothing to see apart from the glorious proms. So, with deep blue skies and no sign of cloud imminent I decided to go for an animation with the Coronado SM90ii, 2x Cemax barlow and the GH3 IMX174 camera. The movement is subtle, but there is a lot going on when you look closely...

Promtastic Sunday - 8th September

The suns disk is blank, really blank!  not much at all is happening, but today all the action was around the limb in the form of prominences.  There were lovely sets on both limbs in the northern hemisphere.  This image has an inverted disk with a limb composite, taken with the Coronado SM90ii and the PGR Grasshopper camera.

Monday, 26 August 2019

Calcium Full Disk 25th August

It seems to have been a while since I imaged in calcium wavelengths, so on Sunday afternoon I decided to go for a full disk with the skywatcher ED80 stopped down to 60mm, coronado 2x cemax barlow and the Grasshopper camera with the homebrew calcium filter.  It was interesting to see the polar faculae are noticeably larger in size than plage bright points mid disk.  The polar faculae in calcium match up very well position wise with these features in the 2 disks prior to this post.

Sodium Full Disk 25th August

I was going for the trio of full disks on Sunday so had to shoot a sodium disk with the Daystar Quark.  There is little to see but around the poles the polar faculae synonymous with solar minimum conditions were visible.  Taken with the Tecnosky 60mm f6 scope.

Ha Full Disk - 25th August

The sun at first sight appears blank again, however a number of small filaments can be seen on the disk; at the south pole the diffuse filaments represent the proms in the previous 2 posts that I did an animation of.  Mid disk a filament and brighter plage are the remnants of the active region that first appeared at Easter time, now with a coronal hole also associated this region is now on it's 4th rotation of our star.  In the northern hemisphere the filaments are associated with the magnetic fields due to sub surface cycle 25 jet stream activity, with a small emphemeral region at the 2 o'clock position being cycle 25.  At the north pole polar faculae can be seen shining through the chromosphere as bright points.  Throw in a few proms too and there is more than meets the eye.  Taken with a Lunt 50C etalon double stacked with a Daystar Quark, Baader solar telecompressor and a FLIR Grasshopper 3 camera.

Sunday, 25 August 2019

Still Raining on the Sun - 24th August

Saturday gave me some free time and with blue skies I decided to try another animation of the active prom region that has been rounding the limb.  I got 140 frames covering 45 minutes real time to produce this animation.  I included an Earth scale just so you can see how small we are in the bigger picture of things that happen on our star.  Taken with the Coronado SM90, 1.6x barlow and Grasshopper IMX174 camera.

Saturday, 24 August 2019

Descending Prominence Knots and Coronal Rain - 23rd August

Friday started grey and misty for me which was frustrating given the forecast was for blue skies, however by early afternoon all the low cloud burnt off to reveal really quite blue skies without the usual haze. I went out and set up and also pleasantly surprised the SSM was coming in with seeing values in the region of 2-3 arc seconds:
I knew this was too much to bother with the HaT so got the SM90ii out. With nothing of note on the disk worth pursuing, I went hunting for the big prom that was visible; Starting off with a 3x barlow it quickly became clear that this scale was going to be too much, so dropped down to the 2x, again too much (I was running files through AS3 on the fly), however dropping down to a magnimax barlow nosepiece giving me a image scale of ~1.6x straight away it was obvious on firecapture this scale to image at was working with the seeing. I decided to opt with the smaller image scale knowing I would get something I could work with rather than waste time (and hard drive space) chasing an elusive super close up that might or might not work out.

Using the Grasshopper with the IMX174 chip I went in automated mode, using the Hinode solar guider to keep the scope squarely on the prom and the SSM and plugin in FC to set a threshold so I was only recording the sharpest of frames. Despite the prom looking pretty quiescent on GONG I could tell from looking visually through the SM90 there was quite a bit of subtle activity with it so decided just to blitz it, and get as much data as my diminutive hard disk would allow. A few passing fluffy clouds interrupted what would have been a perfect run but these have little effect on the result. I managed just shy of 40 minutes of observation from 14.57 to 15.36. I decided to leave the less sharp images in the sequence as they keep the continuity of the movement that was visible, only deleting the cloud sections. I ended up with an animation of 120 frames spanning nearly 40 minutes, so a cadence of about 3 frames a minute.

The result pleasantly surprised me. I aligned in ImPPG with several alignment iterations as Photoshop just locked up every time. I know the image is inverted to the norm, but is looks strange raining the wrong way. It then got me looking around as to whether coronal rain is the right terminology for it, as, traditionally coronal rain is associated with post flare loops, and there was definitely no flaring with this! Turns out there are different categories of coronal rain with the rain in this type being called 'descending prominence knots'. The rain part refers to the condensation of cooler material - plasma on the sun as opposed to water on Earth, however in post flare loops the rain is guided and forms along the magnetic field lines, whereas in this situation the field lines in a prominence are flat (compared to looped) so the rain forms due to temperature differences (instability) in the corona. As the environment is 'viscous' they fall back towards the sun at less than terminal velocity. Given all frames are timestamped and we know image scale it would be quite possible to work out a velocity for these 'descending prominence knots' (or raindrops), i've not done this but theory suggests a few tens of kilometres a second. The science in all this is really very new, this paper ... /1/21/meta from 2014 is perhaps the most comprehensive I found, and heavy going in parts still gives useful information.

The STEREO image suggests a couple of brighter points about to round the limb at these low southern latitudes (remember my ani is vertically inverted), given there latitude this means they are cycle 25, and this is also contemporaneous with the latitude of the prom, so, definitely the area to keep an eye on this weekend.

Hope you like my cinema, just about to head out and see what I can get this morning.

Tuesday, 20 August 2019

Polar Faculae & Cycle 25 Jet Streams - 17th August

The sun may on the face of it be blank at the moment, but there are plenty of subtle signs visible of where we are in relation to solar cycles.  The image above in the top half of the image shows bright polar faculae,  these are magnetic areas on the sun, not strong enough to form sunspots or pores, but strong enough to be visible in a variety of wavelengths; in white light they are visible as white spots on the photosphere, but, higher up in the chromosphere in Ha wavelengths they appear as small bright jet like features shooting upwards.  They only form in the polar regions at solar minimum as the magnetic fields are stable at this time, during solar maximum the poles are under going a magnetic field reversal and so polar faculae are unable to form.

In the bottom half of the image we can see small, dark filaments; regions of plasma held aloft by magnetic fields, however these magnetic fields are in the jet stream regions where we expect to see the tell tale signs of cycle 25.  While these magnetic fields are still quite weak, only able to support filaments, over time their field strength in gauss will increase enough for them to start developing first of all pores and then sunspots, with developed umbra and penumbra.

Taken with the 90mm Coronado SolarmaxII telescope double stacked with a Daystar Quark to increase image contrast by reducing continuum leakage into the image.

Monday, 19 August 2019

Cycle 24 Equatorial Plage - 17th August

These small bright points are plage, the residual magnetism of cycle 24 on the suns equator.  These will slowly but surely become absent as cycle 24 magnetism is cancelled out and cycle 25 starts to become more prevalent at higher latitudes.  Taken with the 90mm Coronado SolarmaxII telescope double stacked with a Daystar Quark to increase contrast  by reducing continuum leakage.

Sunday, 18 August 2019

Ha Full Disk 17th August

Been a while since i've had the time to observe what with one thing and another.  A quick peek at the sun as a whole shows we are still in the depths of solar minimum, one small prom and a few small filaments are about it.  However polar faculae are visible in both hemispheres.  Taken with a Lunt 50 etalon double stacked with a Daystar Quark.

Wednesday, 7 August 2019

Ha Full Disk - 7th August

The sun really is quiet - there's no prominences, no filaments, just a small flux region and a couple of brighter points of plasma around the solar equator, apart from that it's pretty representative of solar minimum conditions.  Taken with the Lunt 50 etalon, Tecnosky 60mm f6 scope, Daystar Quark, 0.7x solar telecompressor and the FLIR GH3 ICX814M camera.

Tuesday, 6 August 2019

Sodium Full Disk 6th August

I remembered yesterday evening I can use the Na Quark for full disks, and ever the optimist and despite looking on the AIA1700 image first thing and seeing yesterdays pores had gone, I still had a go at a full disk, and you know what - the solar dynamics observatory was right, there were no pores or spots remaining. A blank sodium disk then - one day some spots I promise!

Ha Full Disk - 6th August

Up early as usual, we're in unsettled air with jet stream Atlantic weather blowing in, and experience suggests there's normally a brief window of clear skies just after dawn and just before the heat of the sun gets convection going and clouds bubbling up. This was indeed the case and only had enough time for a couple of full disks, first off things in Ha with my preferred setup of Lunt50 etalon, 60mm f6 scope, Daystar Quark, 0.7x solar telecompressor and FLIR GH3 ICX916M camera. Where we had the emerging flux region yesterday seems to have quietened right back down now, but is still quite bright compared to the background disk. A few brighter points in lower southern latitudes mark the tell tale sign of the cycle 25 jet stream, and a few very small proms and filaments are about it for today.

Monday, 5 August 2019

Emerging Flux Regions - 5th August

There were 2 small emerging flux regions visible today on out star.  At its height the EFR on the right also sported small pores where the flux tubes broke through the photosphere, in Ha and higher up in the chromosphere they manifest as darker and cooler regions of plasma that arc and follow the magnetic field lines.  Taken with the Coronado SM90ii double stacked with the Daystar Quark and the FLIR GH3 ICX916M camera.

Old Active Region Remnants - 5th August

If you look back on this website in the archives to April this year you will see we had some quite large active regions gracing the solar equator.  Now, several rotations later this region of turbulent plage is all that remains.  Will it be visible in 2 weeks time when the area rounds the limb again?  Who knows?  Taken with the Coronado SM90 double stacked with the Daystar Quark.