So, here's where we are with the UP transmission from Pleiades Sector KC-U B3-1 8 (target planet) as far as I can tell. The following has been converted to decimal numbers and assumes that the dolphin chirp sound is a division operator. Pauses are transcribed as commas. My comments are in parentheses.
BEGIN TRANSMISSION
WAIL, .979 (don't know what this is)
WAIL, 1, .612 (this is the ratio of target planet surface temp to Merope 5C surface temp)
WAIL, 2, 4.705 (ratio of target planet surface gravity to Merope 5C surface gravity)
WAIL, 3, 5.765 (ratio of target planet radius to Merope 5C radius)
WAIL, 4, 135, 5883.71 EDIT: 588.371 (thanks to CMDR Kloopy for pointing out this mistake), 82, 50.312, 136, .227 (don't know what this is either)
END TRANSMISSION
I think the last block of numbers must be some way of describing the direction and distance from Merope 5C to the target planet or system, but I haven't figured out how yet.