A critical analysis of three near-infrared photometric methods of estimating distances to cataclysmic variables

TL;DR

This paper critically compares three near-infrared photometric methods for estimating distances to cataclysmic variables, finding that Ak et al.'s method is most accurate overall, while others tend to over- or underestimate distances.

Contribution

It provides a comparative analysis of three existing methods against precise trigonometric parallax measurements, highlighting the most reliable approach.

Findings

Ak et al.'s method predicts distances within 4% of parallax measurements.

Beuermann's method overestimates distances by 52%.

Knigge's method underestimates distances by 26%.

Abstract

A critical analysis of three methods of estimating distances to cataclysmic variables (CVs) is performed. These methods, by Ak et al., Beuermann, and Knigge, all use near-infrared (JHK or Ks) magnitudes and the Barnes-Evans relation. We compare all three methods to distances measured by trigonometric parallax by Thorstensen, with Hubble Space Telescope, and with the HIPPARCOS spacecraft. We find that the method of Ak et al. works best overall for all CVs, predicting distances on the average 4% less than those measured by trigonometric parallaxes. The method of Beuermann overestimates distances by 52%. The method of Knigge underestimates distances by 26%, although this was only ever meant as a lower limit, since it assumes all light comes from the secondary star.