A&A Supplement Series, Vol. 125, November I 1997, 497-499
Received December 17, 1996; accepted February 6, 1997
Saul J. AdelmanDepartment of Physics, The Citadel, 171 Moultrie Street, Charleston, SC 29409, U.S.A.
Differential Strömgren uvby photometric observations from the Four College Automated Photoelectric Telescope are used to examine the possible variability of the spectrophotometric standards Vir and 109 Vir. No evidence is found for variability within a season of observation. Small year to year differences are most likely due to unaccounted for extinction changes.
keywords: stars: individual: Vir -- stars: individual: 109 Vir -- stars: variables: other