The Kinematic Distance to NGC 6309

TL;DR

This paper refines the distance to the planetary nebula NGC 6309 using two kinematic methods, providing an updated estimate and comparing it with previous measurements to assess accuracy.

Contribution

It applies and compares two kinematic distance methods to determine the distance to NGC 6309, demonstrating their moderate accuracy in Galactic measurements.

Findings

Distance to NGC 6309 is 4.1 kpc with uncertainties.

The methods yield results within 20-30% of previous measurements.

Both methods show moderate accuracy for Galactic object distances.

Abstract

We report an updated value for the distance to the planetary nebula NGC 6309 (the Box Nebula). The distance is found through two Kinematic Distance Methods (KDMs): the system of two equations reported in Zhu et al. 2013 and the Monte Carlo method reported by Wenger et al. 2018. We find the kinematic distance to NGC 6309 to be 4.1 kpc with an upper uncertainty of +0.29 kpc and a lower uncertainty of -0.38 kpc. We also calculate the distance to Cassiopeia A with the two KDMs and compare to the value reported by Reed et al 1995. The Zhu et al. method and Wenger et al. method yield a value within thirty percent and twenty percent of the Reed et al. method, respectively. The value reported by Reed et al 1995 was contained within the error bounds produced by the Wenger et al. method. The distance measurement to Cassiopeia A suggests that both KDMs, while imperfect, are moderately accurate methods for determining the distance to NGC objects in the plane of the Milky Way.