Re: comparison of Henden's sequence and USNO-based V mags (Re: [vsnet-chat 1376] comparison of GSPC and USNO-based V mags) I have drawn a PostScript figure showing V versus (V_Henden - V_exp) (V_exp expected from USNO A1.0). http://ftp.kusastro.kyoto-u.ac.jp/pub/vsnet/others/Henden/hendenoc.ps The linearlity of the USNO A1.0-based scale over the range V=10-20 looks pretty good; no sign of increased scatter toward the fainter end. However, there are a significant number of stars between V=16 and V=18 for which USNO A1.0 give more than 1 mag fainter than Henden's measurements. Readers who can use USNO A2.0 please check whether this peculiality still remains. Regards, Taichi Kato