Best spectrophotometric standards:
epoch mu a cosd mu d Class V Mag
LTT377 00 41 02.9 -33 44 06 1985 f 11.2
Feige 24 02 32 30.9 +03 30 51 1950 +0.083 +0.010 DAwke 12.42
EG21 03 10 22.1 -68 39 28 1985 DA 11.4
G191B2B=EG247 05 01 31.5 +52 45 52 1950 +0.10 -0.0873 DAwk 11.78
GD71 05 49 34.79 +15 52 37 1950 + -0.1898 DA1 13.03
LTT2415 05 56 24.2 -27 51 26 1985 12.2
EG54 07 40 19.52 -17 24 41 2000 +1.136"/y -0.52" DF 12.98
LTT3218 08 41 33.6 -32 56 55 1985 DA 11.8
EG63 08 47 29.6 -18 59 50 2000 -0.12"/y -0.05"/y DB 15.55
LTT3864 10 31 33.1 -35 33 03 1985 f 12.1
Feige 34=EG71 10 36 41.1 +43 21 50 1950 sdO 11.24
GD153 12 54 35.21 +22 18 09 1950 -0.1898 DA1 13.35
HZ 43 =EG98 13 14 00.7 +29 21 49 1950 -0.149 -0.0813 DAwk 12.91
HZ 44 13 21 19.1 +36 23 38 1950 -0.062 +0.031 sdO 11.67
EG274 16 23 33.7 -39 13 48 2000 DA 11.0
LTT7379 18 36 26.2 -44 18 37 1985 G0 10.2
HD 192281 20 10 46.8 +40 07 01 1950 O5f 7.54
BD+284211=J256 21 48 57.1 +28 37 48 1950 sdOp 10.56
LTT9239 22 52 40.88 -20 35 26 2000 f 12.0
Feige110=EG158 23 17 23.5 -05 26 22 1950 +0.003 -0.003 sdO 11.88
OK standards:
Feige 25 02 36 00.0 +05 15 16 1950 B6V 12.01
Hiltner 600 06 42 37.2 +02 11 25 1950 B1V 10.42
Feige 56 12 04 13.8 +11 56 55 1950 B5p 11.11
Feige 92 14 09 41.3 +50 21 07 1950 Bp 11.62
BD+33 2642 15 50 02.9 +33 05 49 1950 B2 IVp 10.88
BD+40 4032 20 06 40.0 +41 06 15 1950 B2 III 10.45
The first set contains O stars without much Balmer absorption plus
faint southern standards from the list of Stone & Baldwin 1983, MN 204, 347.
The second set is mostly B stars that have a bit of Balmer absorption
and are usually OK.