Jump forward to today… With solar activity at the rock-bottom of the eleven-year solar cycle, while my skills have improved, there are far fewer (maybe 90%) targets available. Surface areas like sunspots and filaments are as rare as hens’ teeth, and even proms often leave one wanting. I say that not to discourage budding solar imagers, as any kind of practice is valuable when one is learning the craft and a newbie should jump at every opportunity.
This morning promises a decent day for imaging. So, as I was going through my routine to make the decision whether-or-not to take a shot I thought I’d jot down a few things that influence my decision for those who are just starting out. These are no particular order, but common sense will guide the reader through their own process.
Equipment: It almost goes without saying, but your equipment needs to be “ready”. Keeping everything in one box will avoid fumbling around when it’s time to set up… One-stop-shopping should be your mantra. It can even come down to the little things, for example if you know where the approximate focus setting is for your scope when mounting it, you’ll avoid delays when bringing the image into focus.
Looking for “targets”: Whether you’re shooting a full disk or a particular feature, the entire process will go much smoother if you know beforehand what you’re going after and where it is located on the sun.
My first target-acquisition software is the NSO/GONG H Alpha Network Monitor (aka “GONG”) located here: http://halpha.nso.edu/ GONG consists of six
At first glance, GONG images might appear devoid of prominences. That’s because the scopes are set at an “average”
Surface features will be obvious in GONG. However, additional information (AR number, for example) regarding sunspots can be obtained at http://www.spaceweather.com/. By selecting the Daily Sun image on the left side, one can get not only the position but the name of sunspots… handy.
What time to shoot?: This may be obvious, but certain things should be in your plan. As the sun travels around the Earth , it will be at its highest point pretty close to noon, standard time for your time zone. Ideally, one should endeavor to shoot between 1100 & 1300hrs, local standard time. This eliminates much of the Earth’s atmosphere between you and your target.
Organization: When first learning, it used to take me an hour to get ready to image. In the desert temps, this can be miserable. From the time I uncover my aligned mount it is less than ten minutes to be ready to image, with a sip of coffee along the way. Being organized will get you there too.
Little things help. For example, I use four scopes for imaging the sun. By marking the various combinations of weights on the balance bar and knowing exactly where the balance point(s) reside for each scope/cam, I can put a scope on the mount perfectly balanced in no time. (Blue painter’s tape is your friend.)
Is the UV/IR-cut filter already residing in front of the diagonal? A note on painter’s tape will keep you from removing the diagonal to check… A little thing, but it helps.
Is your capture software “organized”? Huh? I’m not kidding. I use SharpCap, but this applies to just about every software package. Different cam settings are required when shooting a prom vice, the surface features. By having your general cam settings for each available with a touch of a “Load Settings” button, you can shift from the surface to the proms in a heartbeat. Simple, but effective.
Proms can change rapidly, whereas surface features change much more slowly. Solar rigs need to have the wavelength shifted to catch a prom and re-adjusted to do justice to the surface shot. If you are shooting a full disk, shoot the prom disk, then adjust the wavelength for the surface and shoot it. However, if you’re using a Barlow to get up-close for a “zoomed in” shot of say two different proms, shoot both proms then adjust the wavelength to shoot the accompanying surface shots. It just saves time by avoiding multiple wavelength adjustments. Besides, it’s hot if your head is stuck in that computer box.
One more thing before I quit rambling… When searching for proms on GONG or through the scope, be aware that the vast majority of proms occur at 1330, 1630, 1930, or 2230hr positions around the limb. Yes, we sometimes post proms pointing straight up (North). However, proms appearing at the north or south poles are very, very rare. That’s because of what is generally referred to as the Solar Magnetic Flux Railroad(s) that travel vertically around the east & west limbs.
If you got this far, thanks for the peek.
Clear Skies