value unc_up unc_lo author ref method 6.23 0.380 0.380 Masiero 2014ApJ...791..121M NEATM 6.34 0.079 0.079 Masiero 2011ApJ...741...68M NEATM 6.49 0.230 0.230 Masiero 2012ApJ...759L...8M NEATM