value unc_up unc_lo author ref method 6.25 0.120 0.120 Masiero 2014ApJ...791..121M NEATM 6.29 0.100 0.100 Masiero 2011ApJ...741...68M NEATM 6.68 0.270 0.270 Masiero 2012ApJ...759L...8M NEATM