Thanks for your observations! I have now entered most/all of them into my mid-november model, with an axis at RA 16:15, declination +79.7. It seemed accurate at the time, but had a surprisingly low precession, 0.02 h/y, vs. 1-6 h/y for other flashers I have analyzed. The cone angle was about 86 degrees, which was noted also in nov. 2003, though other observations clustered around 89 degrees, both of which are very normal for comsats. A polar chart showing position of my axis, and of reflecting surfaces at the time of each "first" and "last" bright flash I have noted 2001-2005, is available at http://www.algonet.se/~b_gimle/gif/FlashNormal_T401.htm (Because of the lack of a proper polar chart in Excel, I had to compute and show a X-Y scatter chart, so declinations are 90-abs(value shown)) Starting backwards with some December obs, it looked like a discontinuity in cone angle, jumping back to 89 degrees. Signs of this is also seen in the polar chart above. A similar but smaller effect is seen comparing nov.2003 to dec.2003. Looking at the angles in columns U+V (thought to be different surfaces) there is a jump of 1.5 degrees nov.27-29, but looking at the angle values there is a regular drift before (85-87) and after (89-90). This can be seen in a rectangular plot: http://www.algonet.se/~b_gimle/gif/FlashNormal_T401_Nov-Dec.htm Some pairs of observations (one observer, one day) is indicated by arrows. This cone segment is neither long, nor accurate, enough to calculate its radius. If I assume around 90 degrees angle, I will find a new pole, and will have to find a larger precession rate, to avoid disrupting the near-circle I found. However, there ARE slight indications in the other segments that the axis is/was not where I've put it. The data for nov-dec and some calculations are shown in http://www.algonet.se/~b_gimle/gif/FlashNormal_T401_data.htm /Björn PS1. I will start using a new mail address soon, to try to avoid the amount of spam, without changing ISP. Please be observant. PS2. Question for Rob and other analysts: Is it likely that spin axis precession is around an axis normal to the orbital plane, instead of the equator plane I have assumed so far? COSPAR 5918 +018.1045E ,+59.2985N,22m COSPAR 5919 +018.6172E ,+59.2576N,33m ------------------------------------------------------------------------- Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive: http://www.satobs.org/seesat/seesatindex.html
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