Quantitative Stellar Spectral Classification. IV. Application to the Open Cluster IC 2391

TL;DR

This study tests a stellar spectral classification method on early type stars in open cluster IC 2391, successfully estimating stellar properties and cluster distance with reasonable accuracy, and discusses its strengths and limitations.

Contribution

It is the first application of the Stock & Stock (1999) classification method to early type stars, demonstrating its effectiveness and identifying areas for improvement.

Findings

Estimated cluster distance of 156±24 pc aligns with previous measurements.

Recovered absolute magnitudes and intrinsic colors within expected uncertainties.

Identified strengths and limitations of the spectral classification method.

Abstract

In this work we perform the first test of a stellar spectral classification method (Stock & Stock 1999) by applying it to early type stars. The sample of stars are the members of the open cluster IC 2391 that have high-resolution spectra available in the UVES Project of Paranal Observatory. We show that, in general, absolute magnitudes $M_V$ and intrinsic colors $(B-V)_0$ can be recovered within the uncertainties stated in the original calibration ($\sim 0.4$ for the magnitudes and $\sim 0.03$ for the colors). This accuracy allows us to estimate distances and to infer membership of individual stars to obtain an average distance to the cluster of $156\pm 24$ pc, which is in good agreement with previous reported determinations. Finally, we identify and discuss the real strengths and limitations of this method and we suggest how it can be improved for future studies.