A wavy, twisty jet

Science Nugget: February 25, 2000

In this week's science nugget we examine an X-ray jet which appeared on the east limb of the Sun early last week. We have discussed X-ray jets in previous nuggets [1], [2], [3], [4]; I invite you to look at them. The jet I discuss in this nugget is quite different, though, because it has a really unusual shape and motion.

In the image below I've tried to demonstrate the location of this X-ray jet. The grid pattern shows the eastern limb (or edge) of the Sun, and the arrows are placed along the length of the jet to draw your eye to it. The contrast has been enhanced, and the colors are reversed, but it's still a rather faint structure, definitely not the brightest example we've seen.

Note how long and slender this feature is. A movie is linked below -- this movie shows how the X-ray jet changed and moved during the interval 19:02-21:19 UT on 14-Feb-2000.

You'll notice a few things that are shown by this movie:

In this difference image, the white features are objects that were bright at 21:10:42 UT and the black features are objects that were bright at 21:02:10 UT. The maximum displacement of the slender "trunk" of the X-ray jet is measured between the superimposed bars, and is approximately 23,600 kilometers. Since the time difference between these two images is 512 seconds, we can infer a speed of deformation on the order of 46 km/sec. Also, since the shape of the deformed X-ray jet is somewhat wave-like, we can estimate a corresponding wavelength -- it's on the order of 167 thousand kilometers (give or take a few thousand!).

It would be fair to say that we do not completely understand this motion yet. Count this as a "Gee whiz" Nugget. But it is a beautiful example of the graceful and mystifying motions that are sometimes displayed by magnetized plasmas in the solar atmosphere.

February 25, 2000 D. McKenzie (mckenzie@isass0.solar.isas.ac.jp)