English

The putative old, nearby cluster Lod\'{e}n 1 does not exist

Solar and Stellar Astrophysics 2017-05-16 v1 Astrophysics of Galaxies

Abstract

Astronomers have access to precious few nearby, middle-aged benchmark star clusters. Within 500 pc, there are only NGC 752 and Ruprecht 147 (R147), at 1.5 and 3 Gyr respectively. The Database for Galactic Open Clusters (WEBDA) also lists Lod\'{e}n 1 as a 2 Gyr cluster at a distance of 360 pc. If this is true, Lod\'{e}n 1 could become a useful benchmark cluster. This work details our investigation of Lod\'{e}n 1. We assembled archival astrometry (PPMXL) and photometry (2MASS, Tycho-2, APASS), and acquired medium resolution spectra for radial velocity measurements with the Robert Stobie Spectrograph (RSS) at the Southern African Large Telescope. We observed no sign of a cluster main-sequence turnoff or red giant branch amongst all stars in the field brighter than J<11J < 11. Considering the 29 stars identified by L.O. Lod\'{e}n and listed on SIMBAD as the members of Lod\'{e}n 1, we found no compelling evidence of kinematic clustering in proper motion or radial velocity. Most of these candidates are A stars and red giants, and their observed properties are consistent with distant field stars in the direction of Lod\'{e}n 1 in the Galactic plane. We conclude that the old nearby cluster Lod\'{e}n 1 is neither old, nor nearby, nor a cluster.

Keywords

Cite

@article{arxiv.1605.05330,
  title  = {The putative old, nearby cluster Lod\'{e}n 1 does not exist},
  author = {Eunkyu Han and Jason L. Curtis and Jason T. Wright},
  journal= {arXiv preprint arXiv:1605.05330},
  year   = {2017}
}

Comments

Accepted to AJ

R2 v1 2026-06-22T14:03:09.657Z