Hostname: page-component-8448b6f56d-mp689 Total loading time: 0 Render date: 2024-04-20T00:13:53.905Z Has data issue: false hasContentIssue false
  • English
  • Français

Fringe Interferometry in Space: The Fine Structure of R136A with the Astrometer Fine Guidance Sensor Aboard HST

Published online by Cambridge University Press:  07 August 2017

M.G. Lattanzi ,
R. Burg ,
J.L. Hershey ,
L.G. Taff ,
S.T. Holfeltz  and
B. Bucciarelli
M.G. Lattanzi
Affiliation:
Space Telescope Science Institute, Affiliated with the Astrophysics Division, SSD, ESA; on leave from Oss. Astr. di Torino
R. Burg
Affiliation:
Johns Hopkins University
J.L. Hershey
Affiliation:
Space Telescope Science Institute
L.G. Taff
Affiliation:
Space Telescope Science Institute
S.T. Holfeltz
Affiliation:
Space Telescope Science Institute
B. Bucciarelli
Affiliation:
Osservatorio Astronomico di Torino

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 report on the highest angular resolution observation to date of the bright core, R136a, of the massive star cluster R136 within the 30 Doradus complex in the LMC. This visual observation was obtained with the interferometric fringe mode of operation of Fine Guidance Sensor No. 3 (FGS3) on board HST. Crowding and strong diffuse background from nebular emission make this a challenging observation.

The giant HII region 30 Dor has provided some of the best candidates for the most massive stars, like R136al. We provide evidence for a new component, R136a1B, within the previously known R136a1-a2 system with a separation of 80 mas (or ≈ 4000 au from a1 at the distance of the LMC), and δV = 1.1 mag fainter than the brightest component a1. Estimates from current evolutionary models of massive stars based on the new FGS photometry predict, after subtraction of a1B, that the present mass of R136a1 is 30 M⊙ with a main sequence progenitor of 60 M⊙. To date, this is the lowest direct estimate of the mass of R136a1.

The success of this difficult observation adds a new, unique feature to FGS3 and gives a much expanded, astrophysically very rewarding, role to the interferometer.

Type
1. Current Advances in Astrometry
Information
Symposium - International Astronomical Union , Volume 166: Astronomical and Astrophysical Objectives of Sub-Milliarcsecond Optical Astrometry , 1995 , pp. 95 - 100
Copyright
Copyright © Kluwer 1995 

References

Bernacca, P.L., et al. 1993, A&A, 278, L47.Google Scholar
Bernacca, P.L., et al. 1994, A&A, in press.Google Scholar
Bradley, A. 1994, private communication.CrossRefGoogle Scholar
Burg, et al. 1994, STScI Newsletter, 11, No. 1, p.7).Google Scholar
Hershey, J.L. 1992, PASP, 104, 592.CrossRefGoogle Scholar
Lattanzi, M.G., et al. 1994, ApJ, 427, L21.CrossRefGoogle Scholar
Maeder, A. 1990, A&AS, 84, 139.Google Scholar
Weigelt, G., and Baier, G. 1985, A&A, 150, L18.Google Scholar
Weigelt, G. et al. 1991, ApJ, 378, L22.CrossRefGoogle Scholar