Sunday, October 2, 2011

Twice the fun

Yesterday afternoon I visited one of the local astronomy vendors, Stellar Vision, to see if proprietor Frank Lopez had some hardware that would allow me to piggyback my Lunt 60mm Hydrogen Alpha Telescope onto my recently acquired Astro-Telescopes 102mm f/11 achromat.  I have been using the achromat for white light observations of the Sun and had been thinking about how great it would be if I could have both telescopes mounted simultaneously.  The great thing about Frank is that he is like the Wizard of Oz- he goes behind his curtain (literally) you hear some wheels turning, metal parts clanging around, steam venting, and soon enough out he comes with some hardware that achieves exactly what you are looking for.  Frank has spent years in the telescope business and deals in so much used equipment that I am not sure even he knows how many parts and he has behind the curtain.  At left you can see my current set-up...Thanks to Frank for the mini, ring-top saddle that allows me to piggyback the Lunt!  (Certainly I could have gone online and ordered this part from Losmandy, but I always believe in suporting the local vendor).  While mostly convenient for me, this piggyback arrangement will be very useful for outreach activities.

Click to enlarge
As luck would have it, we are in the middle of about a half-day of clear skies and I was able to get everything together this morning and make my first two sketches of the Sun without changing scopes.  Right away I discovered how fun it is to notice a feature in either white light or hydrogen alpha and then to see if there is any associated feature visible in the other scope.  The skies were not great, with passing cirrus and haze but I was still able to tease out quite a bit of detail, particularly in hydrogen alpha, as seen at right.  This sketch was completed at 1535 UT (8:35 AM local).  Active regions 11302 and 11305 continue to show significant activity as they rotate toward the Western limb.  The spots in 11302 seem to have diminished a bit in size, although the plage and filaments in the region remain complex.  Regions 11306 and 11307 seem to be decaying as the plage areas in these regions are markedly fainter than previous days.  There is a new region that has rounded the NE limb that appears to have a spot (confirmed in white light...yeah!), and the region noted in the SE over the past two days has now been officially numbered 11308.  There is a very large and beautiful prominence associated with this region.

Click to enlarge
At left, is my white light sketch completed about 20 minutes later at 1557 UT (8:57 AM local).  In addition to the numerous spots in the numbered regions, the new region in the northeast contains two very large spots, as well as a smaller spot.  These spots appear elongated when near the solar limb, due to what is called the "Wilson Effect."  This apparent elongation is the result of perspective- Keep in mind that the sun is a sphere.  When looking near the center of the disc we are looking straight into the Solar atmosphere, yet when looking near the limb, we are actually looking across its atmosphere.  Add to this the fact that sunspots are akin to depressions in the solar atmosphere and you get an obvious elongation.  This same effect can be seen looking at craters along the extreme limb of the moon.  

No comments:

Post a Comment