value unc_up unc_lo author ref method 6.54 0.810 0.810 Masiero 2012ApJ...759L...8M NEATM 6.57 0.062 0.062 Masiero 2011ApJ...741...68M NEATM 6.77 0.100 0.100 Masiero 2014ApJ...791..121M NEATM