Multiple interpretations of oumuamua (private)

Could 1I/'Oumuamua be an icy fractal aggregate ejected from a protoplanetary disk? A fluffy radiation-pressure-driven scenario
https://arxiv.org/abs/1902.04100
*** interesting points  ***

One object but multiple & conflicting observations & interpretations


Status - asteroid
Status - comet 
Status - alien spacecraft

Brightness variation - by a factor of 10 (Karen Meech et al)
Brightness variation - by a factor of 6   (David Jewitt et al)

Magnitude differential in lightcurve - 2.5 (Karen Meech et al)
Magnitude differential in lightcurve - 2.0 (David Jewitt et al)
Magnitude differential in lightcurve - 1.2 (Knight et al)

Shape - cigar
Shape - pancake
Shape - lightsail
Shape - contact / prolate binary - (Michele Bannister et al)
 
Width to length ratio - 1:10    (Meech et al)
Width to length ratio - 1:8.4   (Eric Gaidos, 4.2-8.4)
Width to length ratio - 1:7      (Bolin et al, 4-7, paper v2)
Width to length ratio - 1:6      (Jewitt et al)
Width to length ratio - 1:5.3   (Bannister et al)
Width to length ratio - 1:5      (Fraser et al. Avi Loeb believes it too)
Width to length ratio - 1:4.63 (Drahus et al)
Width to length ratio - 1:4      (Bolin et al, 4-7, paper v2 )
Width to length ratio - 1:3      (Knight et al)

Rotation period - 54.48 hours, 13.15, 8.67, 6.58 hrs (Belton et al)
Rotation period - 8.26 hours (David Jewitt et al)
Rotation period - 8.1 hours (Michele Bannister et al)
Rotation period - 7.54 hours (Michal Drahus et al)
Rotation period - 7.3 hours   (Karen Meech et al)
Rotation period - 6.9 - 8.3 hours (Wesley Fraser et al) 
Rotation period - 3 - 5 hours (Knight et al)

Spin - single-axis rotation
Spin - dual-axis rotation/ tumbling

Length - 800 meters (Karen Meech et al)
Length - 440 meters (Nasa Spitzer team)
Length - 230 meters (David Jewitt et al)

Length - 200 meters (Michele Bannister et al)
Length - 160 meters (Michal Drahus et al)
Length - 140 meters (Nasa Spitzer team)
Length - 100 meters (Nasa Spitzer team)

Surface reflectance variation (albeido) - negligible
Surface reflectance variation (albeido) - very high (Avi Loeb)

Surface color variation - 
Surface color variation - 

Density - 0.01 kg m-3                  (Amaya Moro-Martin)
Density - 1,034 kg m-3                (Michal Drahus et al)
Density - 1,500 to 2,800 kg m-3  (Andrew McNeill et al)
Density - 5,900 kg/m-3                (Michele Bannister et al)

Color - reddish
Color - grey
Color - blackish

http://iopscience.iop.org/journal/2041-8205/page/Focus_on_Oumuamua

Bolin et al., Jewitt et al. and Bannister et al. (2017) all detected an 8-hour spin period for `Oumuamua, and found that `Oumuamua appears to be very elongated, with an approximate 5:1 aspect ratio.

Belton et al. (2018) showed that allowable shapes for `Oumuamua include not only the iconic "cigar", but also a "pancake" seen edge-on.

McNeill et al. (2018) used the rotational motion of `Oumuamua to put limits on its density and material properties.