Its after midnight over here in the UK and there will be cloud 5-6 am so no chance of seeing the transit for me. I popped over to the NASA Live stream here http://sunearthday.nasa.gov/webcasts/nasaedge/ for a view and was surprised to see that the images are actually being broadcast via views from readily available amateur solar telescopes. Andy Lunt of Lunt Solar Systems http://www.luntsolarsystems.com/ was explaining the different wavelengths of light that we can view the transit in including Hydrogen Alpha (red), Calcium K (purple blue) and White Light (how we would see it in natural light if it wasn’t so bright – NOTE do not look at the sun directly ! ). I took a set of screenshots from the live feed so that you can see what is going on. It gives you a great impression of the size of the planet Venus relative to the size of the Sun. Earth would typically fit into one of those larger sunspots you can see to the left.
Views courtesy of NASA Live view from Mauna Kea, Hawaii
White Light view 00.21 UT
Calcium K view 00.34 UT
Hydrogen Alpha view 1.45 UT
Above: NASA images of the transit of Venus in 2004
As many of you will know the planet Venus traverses across the face of the sun for 7 hours during the evening of June 5th and very early morning of June 6th 2012 (in the northern hemisphere). This event will not happen again for another 105 years so it truly is a once in a lifetime event. I’m not optimistic of a view from my location as it will only be visible between 5.00 and 5.54 am at less than 10 degrees elevation on the horizon, so it needs a perfectly cloud free view from an elevated site to have the best opportunity and we normally have 78% cloud in early June ! Nevertheless, i’ll be out there with the solar telescopes if it looks at all favorable
If anyone is trying to find out whether the transit will be visible from their location in the northern hemisphere I can recommend the following website http://transitofvenus.nl/wp/where-when/local-transit-times/ which has a handy graphical visibility calculator that is very easy to use. Just pop your postcode into the search box or drag the map to your location.
If the timezones and cloud conspire against you then I can recommend the NASA live broadcast page where you can follow the event in real-time http://venustransit.nasa.gov/transitofvenus/ Another good broadcast site which will be using multiple locations across the globe and telescopes viewing the sun in various wavelengths of light is the Columbus State University site here http://www.ccssc.org/transit2012.html
Hope you all get a view of this rare event. Please remember not to look directly at the sun and do take appropriate safety measures before viewing with the correct equipment. Do get in touch if you have some images and i’ll post them up on the blog – good luck !
Huge active region AR1429 is looking rather benign now as it nears the western limb of the sun’s disk, but just five days ago it produced the largest solar flare of the current solar cycle, an X5 class eruption at 00:28 UT on the 7th March. On the 9th and 10th March it continued to flare at M class levels and large Coronal Mass Ejections (CME’s) were hurled our way on each occasion which will soon be providing plenty of aurora activity in the northern polar regions. Fortunately the cloud parted this afternoon to give me a clear view of this impressively active sunspot group so I took the opportunity to capture it in the CaK and Ha light wavelengths. The hydrogen alpha views show a huge curving filament snaking across the eastern limb. Images taken 12.32- 13.09 UT using Coronado Ha PST/Lunt CaK wedge at 100mm/DMK 41 camera
CAK views of AR 1429:
Hydrogen Alpha Views:
Sunspot group AR 1339 is an impressive sight right now and its high energy Delta class magnetic field has produced some spectacular M-Class flares over the last 24 hours. As it approaches the central meridian of the sun it is worth keeping a watch for X-Class flares from this region which may produce some impressive auroras down here on Earth. AR1339 appears at the top in the images with AR 1338 below. To the left three new active regions are just rounding the limb (AR’s 1340, 1341 & 1342). Images taken 11.21 – 11.46 UT using a DMK41 camera, CaK PST, Ha PST, CaK B1200 diagonal.
Lovely clear blue skies today, but with loads of atmospheric jitter so close up images of the activity were not possible. These Ha and CaK images were taken between 10.30 and 12.30 UT. There are seven active regions gliding over the surface of the sun with lots of nice spot, filament and pore detail. Active regions in the images include 1312, 1313, 1318 on the right and 1314, 1316, 1317, 1319 on the left.
There are currently five active regions forming a band of activity across the sun today including AR1301, 1302, 1305, 1306 and 1307. AR 1302 has given us some pretty impressive flares, but seems to be approaching the western limb in a rather subdued state. Although quiet AR1302 still harbors the magnetic strength to produce some X-Class flares and is still very dynamic visually with some impressive active region filaments arcing high above the main sunspots at its core. Images taken 12.10-12.55 UTC+1 with PST Ha, PST CaK, DMK41.
Close up of AR1302 and its arching filaments. AR 1305 to left
CaK of AR 1302 (right) and AR 1305 (left)
Sunspot AR11302 is a true behemoth at 150,000 km in length. It was crackling with B and C class flares today after calming down somewhat from its release of two X Class flares on the 22nd and 24th September. The spot is now facing Earth and if it releases any more high energy flares in the next couple of days we could see some spectacular aurorae down here around midnight in northern latitudes. Seeing conditions were extremely poor during imaging with a lot of atmospheric turbulence so these images don’t really do justice to the amount of finely structured features that were on view today.
80mm PST Mod Ha view:
CaK PST view:
80mm PST Mod Ha view with bright C Class flare activity in AR 11302:
There are at least eight sunspots and just as many active regions on the sun right now but overall the strength of the magnetic activity remains low with no significant flares.
Very dodgy trying to image the sun today in between fast moving and heavy showers. I gave up after snatching a quick view of the large quiescent prominence visible in the SW at PA 220 degrees. Its a lovely sight with fine hair strands of plasma ascending four earth diameters high above the chromosphere. Another large prominence lifted off the surface earlier this morning with huge arcing strands of plasma floating off into space at PA 300 degrees in the NW. The elongated filament associated with AR 1271 is approaching the limb and should provide a nice filaprom view in the next 24 hours over on the western limb. Over in the east spots in active regions 1277 and 1279 are well defined now.
OK so what the heck is a filaprom image I hear you ask. The term probably originated amongst the solar imagers on the Cloudy Nights Solar Forum http://www.cloudynights.com/ubbthreads/postlist.php/Cat/0/Board/solar to describe the point where a flat surface filament viewed from above crosses over the solar limb and becomes visible as an aerial prominence curving out over the limb. With the larger arching prominences this presents imagers with the opportunity to catch an almost 3D view combining filament and prominence in what we call a filaprom. They are notoriously difficult to capture properly and require a lot of processing to show the filaprom against the surface and floating up above the chromosphere. Users of large aperture solar scopes, particularly the double-stacked variety, will find these much easier to capture, but I wanted to see if it could be done with a PST. The main problems with the PST are the small aperture which doesn’t allow the large magnifications required and the low surface contrast. I found that the best way to try and introduce a hint of that 3D effect is to turn the image negative, boost the contrast slightly and then colourize in a faint colour which retains the filament foot on the surface as well as the prominence arch. Anyway, judge for yourselves whether this has been successful – i’m quite pleased with it ! Images taken with DMK41/PST Ha/PST CaK.
Weak magnetic AR’s 1274 & 1275 with new sunspots rounding the limb to the left