EDP Sciences
Free access
Issue
A&A
Volume 392, Number 3, September IV 2002
Page(s) 937 - 943
Section Formation, structure and evolution of stars
DOI http://dx.doi.org/10.1051/0004-6361:20021185


A&A 392, 937-943 (2002)
DOI: 10.1051/0004-6361:20021185

Diffraction-limited bispectrum speckle interferometry of the Herbig Be star R Mon

G. Weigelt1, Y. Y. Balega2, K.-H. Hofmann1 and T. Preibisch1

1  Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany
2  Special Astrophysical Observatory, Nizhnij Arkhyz, Zelenchuk region, Karachai-Cherkesia 357147, Russia

(Received 17 May 2002 / Accepted 21 June 2002)

Abstract
We explore the structures immediately surrounding the intermediate-mass young stellar object R Mon with bispectrum speckle interferometry, conventional near-infrared imaging and by analyzing optical HST archive data. Our near-infrared speckle images with unprecedented diffraction-limited resolution of 55 mas (~44 AU; H-band) and 76 mas (~61 AU; K-band) represent the highest resolution R Mon images obtained so far and exhibit previously unseen complex structures. While the binary companion R Mon B appears as an unresolved point source in our speckle images, the image of the primary R Mon A is marginally extended in the K-band and significantly extended in the H-band. The most prominent new feature is a bright arc-shaped structure, pointing away from R Mon in north-western direction. We interpret this feature as the surface of a dense structure near the thick circumstellar disk or torus around R Mon. Our images also reveal several twisted filaments of helical shape which are similar to the twisted filaments in the outer parts of the nebula. We identify structures which probably are responsible for casting pronounced shadows in the outer regions of the NGC 2261 reflection nebula. Finally, we discuss the relation of the observed features, in particular the arc-shaped speckle feature, to the wind and outflow activity (Herbig-Haro objects and jets) of R Mon.


Key words: techniques: interferometric -- stars: individual: R Mon -- stars: formation -- stars: winds, outflows

Offprint request: G. Weigelt, weigelt@mpifr-bonn.mpg.de

SIMBAD Objects in preparation



© ESO 2002