If single main sequence band early A stars such as 109 Vir are low amplitude photometric variables (Taylor 1982, 1984), then our understanding of these stars needs to be revised. In an attempt to confirm or to set limits on such claims I use differential Strömgren uvby photometry obtained with 0.75-m Four College Automated Photoelectric Telescope (FCAPT) on Mt. Hopkins, AZ. Its first year of operation was Sept. 1990 - July 1991. The telescope measured the dark count and then in each filter the sky-ch-c-v-c-v-c-v-c-ch-sky where sky is a reading of the sky, ch that of the check star, c that of the comparison star, and v that of the variable star. From measuring two non-variable stars for each potentially variable star, one can derive an estimate of the accuracy of the photometry. Table 1 (click here) contains the yearly and total means and standard deviations while Tables 2 and 3 contain this information and the observations. No corrections have been made for neutral density filter differences among each group of variable, comparison, and check stars.
| u | v | b | y | |||||
| v-c | ch-c | v-c | ch-c | v-c | ch-c | v-c | ch-c | |
 Vir | ||||||||
| year 2 | ||||||||
| average | 0.315 | 0.587 | 0.177 | 0.268 | 0.221 | 0.518 | 0.238 | 0.750 |
| std. dev. | 0.006 | 0.006 | 0.009 | 0.007 | 0.011 | 0.008 | 0.012 | 0.009 |
| year 3 | ||||||||
| average | 0.322 | 0.586 | 0.178 | 0.273 | 0.217 | 0.521 | 0.239 | 0.751 |
| std. dev. | 0.009 | 0.005 | 0.008 | 0.005 | 0.009 | 0.006 | 0.011 | 0.006 |
| year 4 | ||||||||
| average | 0.325 | 0.582 | 0.180 | 0.271 | 0.210 | 0.524 | 0.237 | 0.755 |
| std. dev. | 0.009 | 0.007 | 0.005 | 0.004 | 0.005 | 0.004 | 0.005 | 0.004 |
| year 5 | ||||||||
| average | 0.322 | 0.586 | 0.181 | 0.273 | 0.208 | 0.526 | 0.234 | 0.755 |
| std. dev. | 0.009 | 0.007 | 0.005 | 0.005 | 0.005 | 0.004 | 0.005 | 0.005 |
| years 2-5 | ||||||||
| average | 0.322 | 0.584 | 0.180 | 0.272 | 0.211 | 0.524 | 0.236 | 0.754 |
| std. dev. | 0.009 | 0.007 | 0.006 | 0.005 | 0.007 | 0.005 | 0.007 | 0.006 |
| 109 Vir | ||||||||
| year 2 | ||||||||
| average | -1.851 | 0.830 | -1.925 | 0.739 | -1.942 | 1.005 | -1.947 | 1.191 |
| std. dev. | 0.004 | 0.004 | 0.006 | 0.006 | 0.006 | 0.005 | 0.005 | 0.006 |
| year 3 | ||||||||
| average | -1.849 | 0.840 | -1.923 | 0.755 | -1.940 | 1.017 | -1.945 | 1.203 |
| std. dev. | 0.004 | 0.007 | 0.003 | 0.006 | 0.003 | 0.005 | 0.004 | 0.006 |
| year 4 | ||||||||
| average | -1.849 | 0.838 | -1.933 | 0.759 | -1.955 | 1.025 | -1.960 | 1.212 |
| std. dev | 0.004 | 0.008 | 0.003 | 0.005 | 0.003 | 0.004 | 0.003 | 0.005 |
| year 5 | ||||||||
| average | -1.848 | 0.839 | -1.932 | 0.762 | -1.955 | 1.029 | -1.961 | 1.214 |
| std. dev. | 0.004 | 0.005 | 0.003 | 0.004 | 0.003 | 0.004 | 0.004 | 0.004 |
| years 2-5 | ||||||||
| average | -1.849 | 0.838 | -1.931 | 0.758 | -1.952 | 1.024 | -1.958 | 1.211 |
| std. dev. | 0.004 | 0.007 | 0.005 | 0.007 | 0.006 | 0.008 | 0.007 | 0.008 |