Hostname: page-component-cd9895bd7-jn8rn Total loading time: 0 Render date: 2024-12-22T05:23:30.555Z Has data issue: false hasContentIssue false

Distance and Size of the Red Hypergiant NML Cyg

Published online by Cambridge University Press:  24 July 2012

B. Zhang
Affiliation:
Max-Plank-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany email: bzhang@mpifr.de Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai 200030, China
M. J. Reid
Affiliation:
Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA
K. M. Menten
Affiliation:
Max-Plank-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany email: bzhang@mpifr.de
X. W. Zheng
Affiliation:
Department of Astronomy, Nanjing University, 22 Hankou Road, Nanjing 210093, China
A. Brunthaler
Affiliation:
Max-Plank-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany email: bzhang@mpifr.de
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

We present astrometric results of phase-referencing VLBI observations of 22 GHz H2O maser and 43 GHz SiO maser emission towards the red hypergiant NML Cyg using VLBA. We obtained an annual parallax of 0.62 ± 0.04 mas, corresponding to a distance of 1.61+0.13−0.11 kpc. With a VLA observation in its largest (A) configuration at 43 GHz, we barely resolve the radio photosphere of NML Cyg, and find a uniform-disk diameter of 44 ± 16 mas.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2012

References

Blöcker, T., Balega, Y., Hofmann, K.-H., & Weigelt, G. 2001, A&A, 369, 142Google Scholar
Massey, P. & Thompson, A. B. 1991, AJ, 101, 1408CrossRefGoogle Scholar
Morris, M. & Jura, M. 1983, ApJ, 267, 179CrossRefGoogle Scholar
Reid, M. J. & Menten, K. M. 2007, ApJ, 671, 2068CrossRefGoogle Scholar
Schuster, M. T., Humphreys, R. M., & Marengo, M. 2006, AJ, 131, 603CrossRefGoogle Scholar
Schuster, M. T., et al. 2009, ApJ, 699, 1423CrossRefGoogle Scholar
Zhang, B., Reid, M. J., Menten, K. M., & Zheng, X. W. 2012, ApJ, 744, 23CrossRefGoogle Scholar