Analysis of determinations of the distance between the sun and the galactic center

The paper investigates the question of whether or not determinations of the distance between the Sun and the Galactic center R ₀ are affected by the so-called “bandwagon effect”, leading to selection effects in published data that tend to be close to expected values, as was suggested by some authors. It is difficult to estimate numerically a systematic uncertainty in R ₀ due to the bandwagon effect; however, it is highly probable that, even if widely accepted values differ appreciably from the true value, the published results should eventually approach the true value despite the bandwagon effect. This should be manifest as a trend in the published R ₀ data: if this trend is statistically significant, the presence of the bandwagon effect can be suspected in the data. Fifty two determinations of R ₀ published over the last 20 years were analyzed. These data reveal no statistically significant trend, suggesting they are unlikely to involve any systematic uncertainty due to the bandwagon effect. At the same time, the published data show a gradual and statistically significant decrease in the uncertainties in the R ₀ determinations with time.