airmass coefficients
hst standard star spectra
Bohlin, Dickinson, & Calzetti 2001
HZ 4
G191B2B
BD+75deg325
Feige 34
HD 93521
HZ 21
Feige 66
Feige 67
HZ 44
GRW+70deg5824
BD+33deg2642
BD+28deg4211
BD+25deg4655
LTT 9491
Feige 110
GD 50
GD 108
NGC 7293