Statistical analysis of the determinations of the Sun's Galactocentric distance

TL;DR

This paper analyzes 53 measurements of the Sun's distance from the Galactic center over 20 years, assessing data consistency and trends, and finds that estimates are consistent with no significant recent trend, despite improved error estimates.

Contribution

It provides a comprehensive statistical analysis of recent Ro measurements, confirming their internal consistency and evaluating potential biases or trends.

Findings

Measurements are internally consistent.

No significant trend in Ro estimates over 20 years.

Formal errors have decreased over time.

Abstract

Based on several tens of Ro measurements made during the past decades, several studies have been performed to derive the best estimate of Ro. Some used just simple averaging to derive a result, whereas others provided comprehensive analyses of possible errors in published results. In either case, detailed statistical analyses of data used were not performed. However, a computation of the best estimates of the Galactic rotation constants is not only an astronomical but also a metrological task. Here we perform an analysis of 53 Ro measurements (published in the past 20 years) to assess the consistency of the data. Our analysis shows that they are internally consistent. It is also shown that any trend in the Ro estimates from the last 20 years is statistically negligible, which renders the presence of a bandwagon effect doubtful. On the other hand, the formal errors in the published Ro estimates improve significantly with time.