Astron. Astrophys. 346, 441-452 (1999)

The circumstellar environment of IRAS 05327+3404

E.A. Magnier ^1,2, L.B.F.M. Waters ^1,3, P.J. Groot ¹, M.E. van den Ancker ¹, Y.-J. Kuan ^4,5 and E.L. Martín <sup>6,7

1</sup> Astronomical Institute "Anton Pannekoek" and CHEAF, Kruislaan 403, 198 SJ Amsterdam, The Netherlands
² Astronomy Dept. 351580, University of Washington, Seattle, WA 98195, USA
³ SRON Laboratory for Space Research Groningen, P.O. Box 800, 9700 AV Groningen, The Netherlands
⁴ Department of Earth Sciences, National Taiwan Normal University, Taipei, Taiwan
⁵ Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 1-87, Nankang, Taipei, Taiwan
⁶ Instituto de Astrofísica de Canarias, E-38200 La Laguna, Tenerife, Spain
⁷ Astronomy Dept., 601 Campbell Hall, University of California at Berkeley, CA 94720, USA

Received 20 February 1998 / Accepted 21 August 1998

Abstract

We continue our study of the young stellar object associated with IRAS 05327+3404. We have determined the spectral type of the central star to be K2. We show that the star is most likely seen directly, not via a reflection, and that the extinction is only mag. The spectral energy distribution shows the presence of large amounts of circumstellar material. Near-IR and optical observations of the reflection nebula also demonstrate the presence of circumstellar material, and show the material to be arranged in a disk with a relatively wide central hole of 33^o opening angle. The central hole and a CO outflow are co-aligned, and are roughly aligned with the ionized outflow. Several surprising aspects remain: Although the system has a strong ionized outflow, there is little or no evidence of active accretion in the form of UV excess, veiling, or strong high-Balmer line emission. Also, the spectral energy distribution is very wide, and suggests that the original birth cloud had a large rotational velocity. We propose that the relative isolation of the system from other star formation activity may explain the relatively large circumstellar disk for a system with a well-exposed central star.

Key words: stars: circumstellar matter stars: evolution stars: formation stars: mass-loss stars: pre-main sequence

Send offprint requests to: Eugene A. Magnier

Correspondence to: gene@astro.uva.nl

SIMBAD Objects

Contents

• 1. Introduction
• 2. Observations
  • 2.1. JCMT observations
  • 2.2. UKIRT observations
  • 2.3. NOT observations
  • 2.4. INT observations
• 3. The central source
  • 3.1. Spectral type and veiling
  • 3.2. Spectral energy distribution
• 4. The reflection nebula
  • 4.1. Scattered light model
  • 4.2. Analysis of the images
  • 4.3. Direct image or reflection?
• 5. The molecular outflow
• 6. IRAS 05327+3404 (Holoea) in an evolutionary context
• 7. Conclusions
• Acknowledgements
• References

© European Southern Observatory (ESO) 1999

Online publication: May 21, 1999
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