Nov 11


Okay, here I go with the word-play.  I am being Sirius, though.  No, Siriusly…

As I previously mentioned, the astronomical viewing conditions on the night of the total lunar eclipse could not have been much better than they were for our area of the world.  Given the fact that the first detectable trace of penumbra was not scheduled to become visible until 03:09 am, I took advantage of the clear skies and poked around with my telescope.

While I was preparing to view and image the Orion Nebula, something caught my eye about 20° above the Southeast horizon.  It was really big, really bright and flashing all the colors of the rainbow (ROYGBIV) in rapid succession.  It was like a stellar strobe light!  The app I usually use to find and identify deep space targets, “Sky Tonight,” appeared to indicate that the bright, flashing object was the asteroid 2016 PD1.  Without wasting any time, I hurriedly aimed my telescope at the strobe light in the sky and took a quick video with my phone through a 25mm eyepiece.  Once the footage was secured I then decided I needed a second opinion from a different space object-finding app, “Sky Safari.”  I was doubtful that it was actually an asteroid since those things are usually described as being “the size of a school bus.”  Because it looked so cool I didn’t really care what it was or what it was called.  I just HAD to know what I was observing.

That’s when things got Sirius.  No, Siriusly!  What I had in fact been observing was the bright star Sirius.  Dr. Stuart Clark, astronomy columnist at The Guardian has this to say about the bright flashing:

“….Another characteristic of Sirius is that it twinkles. This rapid flashing of colour and brightness is caused by the star’s light being refracted in the layers of Earth’s atmosphere. It is most pronounced when Sirius is low and so its light is travelling through more atmosphere to reach our eyes. As it rises higher into the sky, the twinkling diminishes. All stars twinkle, it is just more noticeable with Sirius because it is so bright.”

Notice that if you visualize a line running through the three stars of Orion’s belt, they point to Sirius.

Here’s a video slideshow I put together demonstrating the rapid flashing of colors visible when Sirius is low in the sky.  Interestingly, this slideshow is comprised of screenshots taken from my original video.  All the images were taken from frames in only 1 second of the video!

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