dc.contributor.author | Kraus, Stefan | |
dc.contributor.author | Calvet, Nuria | |
dc.contributor.author | Hartmann, Lee | |
dc.contributor.author | Hofmann, Karl-Heinz | |
dc.contributor.author | Kreplin, Alexander | |
dc.contributor.author | Monnier, John D. | |
dc.contributor.author | Weigelt, Gerd | |
dc.date.accessioned | 2015-01-08T14:05:23Z | |
dc.date.issued | 2012-01-18 | |
dc.description.abstract | Belonging to the group of B[e] stars, V921 Scorpii is associated with a strong infrared excess and permitted and forbidden line emission, indicating the presence of low- and high-density circumstellar gas and dust. Many aspects of V921 Sco and other B[e] stars still remain mysterious, including their evolutionary state and the physical conditions resulting in the class-defining characteristics. In this Letter, we employ Very Large Telescope Interferometer/AMBER spectro-interferometry in order to reconstruct high-resolution (λ/2B = 0."0013) model-independent interferometric images for three wavelength bands around 1.65, 2.0, and 2.3 μm. In our images, we discover a close (25.0 ± 0.8 mas, corresponding to ~29 ± 0.9 AU at 1.15 kpc) companion around V921 Sco. Between two epochs in 2008 and 2009, we measure orbital motion of ~7°, implying an orbital period of ~35 years (for a circular orbit). Around the primary star, we detect a disk-like structure with indications for a radial temperature gradient. The polar axis of this AU-scale disk is aligned with the arcminute-scale bipolar nebula in which V921 Sco is embedded. Using Magellan/IMACS imaging, we detect multi-layered arc-shaped substructure in the nebula, suggesting episodic outflow activity from the system with a period of ~25 years, roughly matching the estimated orbital period of the companion. Our study supports the hypothesis that the B[e] phenomenon is related to dynamical interaction in a close binary system. | en_GB |
dc.description.sponsorship | NASA through the Sagan Fellowship Program | en_GB |
dc.identifier.citation | Vol. 746, article L2 | en_GB |
dc.identifier.doi | 10.1088/2041-8205/746/1/L2 | |
dc.identifier.uri | http://hdl.handle.net/10871/16130 | |
dc.language.iso | en | en_GB |
dc.publisher | IOP Publishing for American Astronomical Society | en_GB |
dc.subject | accretion, accretion disks | en_GB |
dc.subject | binaries: close | en_GB |
dc.subject | protoplanetary disks | en_GB |
dc.subject | stars: individual (V921 Scorpii) | en_GB |
dc.subject | stars: pre-main sequence | en_GB |
dc.subject | techniques: interferometric | en_GB |
dc.title | On the Nature of the Herbig B[e] Star Binary System V921 Scorpii: Discovery of a Close Companion and Relation to the Large-scale Bipolar Nebula | en_GB |
dc.type | Article | en_GB |
dc.date.available | 2015-01-08T14:05:23Z | |
dc.identifier.issn | 2041-8205 | |
dc.description | Copyright © 2012 IOP Publishing / American Astronomical Society | en_GB |
dc.identifier.eissn | 2041-8213 | |
dc.identifier.journal | Astrophysical Journal Letters | en_GB |