Here Comes the Sun!


I can count on one hand how many shots of the Sun I’ve taken in the last decade that weren’t at an eclipse, or a sunrise/sunset. I just don’t do much solar shooting. But today I had to resurrect some old gear to get this shot. The Sun was putting on a fabulous show this afternoon (Sunday, June 5, 2011) with an army of huge prominences rimming the edge of the Sun. Very impressive. And looking very HOT!

After 2 to 3 years of record low activity, the Sun is picking up, returning to its normal self, with sunspots and prominences a daily occurrence. But these were especially dramatic. Each of these prominence “flames: towers tens of thousands of kilometre above the surface of the Sun. The Earth would be a dot next to one of them.

To get this shot, I created a masked composite in Photoshop of two exposures, a short 1/13s second shot to record the disk detail, and a long 1/2 second shot to record the fainter limb prominences. For a telescope I used my little Coronado PST H-alpha scope, a special scope just for solar viewing that filters out all but a narrow wavelength of red light, allowing the prominences to be seen.

Trouble is, my DSLR cameras won’t reach focus on the Coronado scope. So I dusted off the little 2003 vintage Sony DSC-V1 point and shoot camera and a Scopetronix 40mm eyepiece and “afocal” adapter, so the camera was screwed onto and looking into the eyepiece which was then inserted into the scope. I hadn’t used an afocal setup like that since the Venus transit in 2004.

It was tough to focus the stack, so focus was a bit of a guess — it was helped here with a liberal application of Photoshop’s Smart Sharpen filter! In all, it is a crude system but in a pinch it does work. Maybe I’ll have to get better gear just to take solar shots. With the Sun becoming more active, there certainly will be lots more to shoot.

— Alan, June 5, 2011 / Image © 2011 Alan Dyer

 

Saturn Sidles Up to a Star


If you look up this week, to the southwest, you’ll see a bright star in the evening twilight that, upon close inspection, is really a tight double star. The fainter companion becomes obvious as it gets dark. The bright member of the pair is actually Saturn, and its fainter companion is the star Porrima, a.k.a. Gamma Virginis. And they are unusually close!

This week Saturn (at bottom here) sidles up to Porrima (at top), getting so close both are contained in a high-power telescope field, which is what this shot depicts. I took it Saturday night, June 4, when Saturn was about 1/4° (16 arc minutes) from Porrima. But by June 10 their separation will be a tad less, at 15 arc minutes apart. This week Saturn stops its annual retrograde motion just shy of Porrima.

The pairing made a wonderful sight in the telescope tonight, especially because of the “good seeing” — so Saturn looked very sharp. And Porrima, itself a very tight double star, was easy to split at 200x, appearing like a pair of headlights at high power. (The photo doesn’t split Porrima.)

But the nicest view is just naked eye — Saturn and Porrima are forming a rare and temporary double star easy to split with no optical aid but looking much more striking than any other naked eye double. The pairing won’t last long — Saturn turns around near Porrima this week, then begins to head east again away from its stellar partner.

The shot also picks up four of Saturn’s moons: Dione very close to Saturn, then Tethys, and Rhea in a row from left to right, and bright Titan below the trio.

This a stack of five 5-second exposures at ISO 1600 with a Canon 7D attached to my 130mm Astro-Physics refractor with a 2x Barlow, giving an effective focal length of about 1600mm and f/12. I took this in twilight to add the blue sky.

— Alan, June 5, 2011 / Image © 2011 Alan Dyer