[Steely Tom]

That the frequency-vs-time relationship is a curve would seem to indicate that the phenomenon is due to physics, not an attempt to communicate information from a distant civilization.

If the f/t relationship had been dead linear, a perfect straight line, I'd be much more inclined to give a big "Hmm!"

[TXnMA]

Same here. Something about that curve says, "Doppler" to me.

Been trying to envision a signal emitted from the bottom of a deep shaft -- on a spherical object that is (very) rapidly "tumbling" on multiple axes. On most passes, (except perfectly on-axis) it seems to me that even a linear signal would have some circular doppler distortion in frequency...

But, that would seem to be more "natural" than "designed".

What blows my mind is the sheer power of the beast! Even with inverse square attenuation over millions of light years of distance, that is a "bright" signal... (That, of course, assumes that the astrofolks got their source correctly identified...)

[Tucker39]

Thanks.

[pfflier]

Agree. At that distance, any entity would not travel fast enough to generate a curve. That is assuming that no entity can travel faster that the speed of light.