Predicting alpha Comae Berenices Time of Eclipse II: How 3 Faulty Measurements Out of 609 Caused A 26 Year Binary's Eclipse To Be Missed

TL;DR

This paper investigates how three erroneous historical measurements significantly impacted the prediction of an eclipse in a 26-year binary star system, leading to a missed eclipse event.

Contribution

It identifies the influence of faulty data on orbital modeling and emphasizes the importance of data accuracy in eclipse predictions.

Findings

Three incorrect measurements skewed the orbital model.

The actual eclipse likely occurred two months earlier than predicted.

Data errors caused the eclipse to be missed due to observational timing.

Abstract

The dwarf stars in the 26 year period binary alpha Com were predicted to eclipse each other in early 2015. That prediction was based on an orbit model made with over 600 astrometric observations using micrometers, speckle interferometry, and long baseline optical interferometry. Unfortunately, it has been realized recently that the position angle measurements for three of the observations from ~100 years ago were in error by 180 degrees, which skewed the orbital fit. The eclipse was likely 2 months earlier than predicted, at which point the system was low on the horizon at sunrise.