TY - JOUR
T1 - THE PUTATIVE OLD, NEARBY CLUSTER LODÉN 1 DOES NOT EXIST
AU - Han, Eunkyu
AU - Curtis, Jason L.
AU - Wright, Jason T.
N1 - Funding Information:
This work was supported by the National Science Foundation under grant No. AST-1211785, and the Center for Exoplanets and Habitable Worlds at Penn State. J.C. acknowledges support from the National Science Foundation Graduate Research Fellowship Program under NSF grant No. DGE1255832. This research made use of Montage, funded by NASAs Earth Science Technology Office, Computation Technologies Project, under Cooperative Agreement Number NCC5-626 between NASA and the California Institute of Technology. Montage is maintained by the NASA/IPAC Infrared Science Archive. This research was made possible through the use of the AAVSO Photometric All-Sky Survey (APASS), funded by the Robert Martin Ayers Sciences Fund.
Publisher Copyright:
© 2016. The American Astronomical Society. All rights reserved.
PY - 2016/7
Y1 - 2016/7
N2 - 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 Lodén 1 as a 2 Gyr cluster at a distance of 360 pc. If this is true, Lodén 1 could become a useful benchmark cluster. This work details our investigation of Lodén 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 at the Southern African Large Telescope. We observed no sign of a cluster main-sequence turnoff or red giant branch among all stars in the field brighter than < J 11. Considering the 29 stars identified by L.O. Lodén and listed on SIMBAD as the members of Lodén 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 Lodén 1 in the Galactic plane. We conclude that the old nearby cluster Lodén 1 is neither old, nor nearby, nor a cluster.
AB - 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 Lodén 1 as a 2 Gyr cluster at a distance of 360 pc. If this is true, Lodén 1 could become a useful benchmark cluster. This work details our investigation of Lodén 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 at the Southern African Large Telescope. We observed no sign of a cluster main-sequence turnoff or red giant branch among all stars in the field brighter than < J 11. Considering the 29 stars identified by L.O. Lodén and listed on SIMBAD as the members of Lodén 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 Lodén 1 in the Galactic plane. We conclude that the old nearby cluster Lodén 1 is neither old, nor nearby, nor a cluster.
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U2 - 10.3847/0004-6256/152/1/7
DO - 10.3847/0004-6256/152/1/7
M3 - Article
AN - SCOPUS:84978289813
SN - 0004-6256
VL - 152
JO - Astronomical Journal
JF - Astronomical Journal
IS - 1
M1 - 7
ER -