The distances to star-clusters hosting Red Supergiants: $\chi$ Per, NGC 7419, and Westerlund 1

Abstract

Galactic, young massive star clusters are approximately coeval aggregates of stars, close enough to resolve the individual stars, massive enough to have produced large numbers of massive stars, and young enough for these stars to be in a pre-supernova state. As such these objects represent powerful natural laboratories in which to study the evolution of massive stars. To be used in this way, it is crucial that accurate and precise distances are known, since this affects both the inferred luminosities of the cluster members and the age estimate for the cluster itself. Here we present distance estimates for three star clusters rich in Red Supergiants ($\chi$ Per, NGC 7419 and Westerlund 1) based on their average astrometric parallaxes $\bar{\pi }$ in Gaia Data Release 2, where the measurement of $\bar{\pi }$ is obtained from a proper-motion screened sample of spectroscopically-confirmed cluster members. We determine distances of $d=2.25_{-0.14}^{+0.16}$kpc, $d=3.00_{-0.29}^{+0.35}$kpc, and $d=3.87_{-0.64}^{+0.95}$kpc for the three clusters respectively. We find that the dominant source of error is that in Gaia's zero-point parallax offset ${\pi }_{\mathrm{ZP}}$, and we argue that more precise distances cannot be determined without an improved characterization of this quantity.

arXiv comment5 pages, 9 figures, to appear in MNRAS

References in corpus (27)

• Gaia Data Release 2. Summary of the contents and survey properties
• The Gaia mission
• Gaia Data Release 2: The astrometric solution
• New Parallaxes of Galactic Cepheids from Spatially Scanning the Hubble Space Telescope: Implications for the Hubble Constant
• Physical Parameters and Wind Properties of Galactic Early B Supergiants
• Evidence for a systematic offset of -80 micro-arcseconds in the Gaia DR2 parallaxes
• On the massive stellar population of the Super Star Cluster Westerlund 1
• The most massive stars in the Arches cluster
• The Progenitor Masses of Wolf-Rayet Stars and Luminous Blue Variables Determined from Cluster Turn-offs. II. Results from 12 Galactic Clusters and OB Associations
• Fitting the young main-sequence; distances, ages and age spreads
• The Star Formation History and Mass Function of the Double Cluster h and Chi Persei
• Intermediate to low-mass stellar content of Westerlund 1
• The cool supergiant population of the massive young star cluster RSGC1
• Radiative hydrodynamics simulations of red supergiant stars. III. Spectro-photocentric variability, photometric variability, and consequences on Gaia measurements
• The Stellar Population of h and chi Persei: Cluster Properties, Membership, and the Intrinsic Colors and Temperatures of Stars
• The progenitor mass of the magnetar SGR1900+14
• The distance and neutral environment of the massive stellar cluster Westerlund 1
• The G305 star-forming complex: the central star clusters Danks 1 and Danks 2
• The evolution of Red Supergiants to supernova in the LMC cluster NGC 2100
• Distance and Proper Motion Measurement of the Red Supergiant, S Persei, with VLBI H2O Maser Astrometry
• Testing systematics of Gaia DR2 parallaxes with empirical surface brightness -- color relations applied to eclipsing binaries
• Discrepancies in the ages of young star clusters; evidence for mergers?
• NGC 7419 as a template for red supergiant clusters
• SiO maser emission from red supergiants across the Galaxy: I. Targets in massive star clusters
• NGC 7419: A young open cluster with a number of very young intermediate mass pre-MS stars
• Multi-wavelength study of a young open cluster NGC 7419
• A VLT/FLAMES survey for massive binaries in Westerlund 1 V. the X-ray selected blue stragglers Wd1-27 and -30a

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• A new mass-loss rate prescription for red supergiants
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• A deep spectromorphological study of the $\gamma$-ray emission surrounding the young massive stellar cluster Westerlund 1
• The Age of Westerlund 1 Revisited
• Exploring the Mass Loss Histories of the Red Supergiants
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• Understanding the TeV $\gamma$-ray emission surrounding the young massive star cluster Westerlund 1
• The impact of realistic red supergiant mass-loss on stellar evolution
• Westerlund 1 under the light of Gaia EDR3: Distance, isolation, extent, and a hidden population
• Distances to Galactic OB-stars: Photometry vs. Parallax
• Probing Red Supergiant dynamics through photo-center displacements measured by Gaia
• High-resolution spectroscopic study of massive blue and red supergiants in Per OB1
• Distance and age of the massive stellar cluster Westerlund 1. I. Parallax method using Gaia-EDR3
• Distance and age of the massive stellar cluster Westerlund 1. II. The eclipsing binary W36
• On the hadronic origin of the very high energy $\gamma$-ray emission surrounding the young massive stellar cluster Westerlund 1
• Quantifying Systematic Age Discrepancies in Very Young Star Clusters