A&A 455, 1001-1008 (2006)
DOI: 10.1051/0004-6361:20054609

An outbursting protostar of the FU Orionis type in the Cygnus OB7 molecular cloud

T. A. Movsessian¹, T. Khanzadyan^{2, 3}, C. Aspin⁴, T. Yu. Magakian¹, T. Beck⁴, A. Moiseev⁵, M. D. Smith^{6, 7} and E. H. Nikogossian<sup>1

1</sup>  Byurakan Astrophysical Observatory, 378433 Aragatsotn reg., Armenia
    e-mail: tigmov@web.am;tigmag@sci.am;elena@bao.sci.am
²  Centro de Astrofísica da Universidade do Porto, Rua das Estrelas, 4150 - 762 Porto, Portugal
    e-mail: khtig@astro.up.pt
³  Max-Planck Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany
⁴  Gemini Observatory, 670 N. Aohoku Place, Hilo, HI 96720
    e-mail: caa@gemini.edu,tbeck@gemini.edu
⁵  Special Astrophysical Observatory, N.Arkhyz, Karachaevo-Cherkesia, 369167 Russia
    e-mail: moisav@sao.ru
⁶  Armagh Observatory, College Hill, Armagh BT61 9DG, Northern Ireland, UK
    e-mail: mds@arm.ac.uk
⁷  Centre for Astrophysics and Planetary Science, University of Kent, CT2 7NR, UK

(Received 30 November 2005 / Accepted 18 May 2006)

Abstract
Context.To follow the early evolution of stars we need to understand how young stars accrete and eject mass. It is generally assumed that the FU Orionis phenomenon is related to the variations in the disk accretion, but many questions remain still open, in particular because of the rarity of FU Ori type stars.
Aims.We explore here the characteristics of the outburst and of the environment of one new object, discovered recently in the active star formation region containing RNO 127, within the Cygnus OB7 dark cloud complex.
Methods.We present an extensive optical and near-infrared study of a new candidate of FU Orionis object, including its direct imaging, spectroscopy and scanning Fabry-Pérot interferometry.
Results.The source, associated with the variable reflection nebula, underwent prodigious outburst. The "Braid" nebula, which appeared in 2000, as is indicated by its name, consists of two intertwined features, illuminated by the outburst. Subsequent NIR observations revealed the bright source, which was not visible on 2MASS images, and its estimated brightening was more than 4 mag. Optical and infrared spectral data show features, which are necessary for the system to be referred to as a FUor object. The bipolar optical flow directed by the axis of nebula also was found. Various estimates give the November/December 1999 as the most probable date for the eruption.

Key words: ISM: jets and outflows -- ISM: clouds

© ESO 2006

The OpenURL standard is a protocol for transmission of metadata describing the resource that you wish to access. An OpenURL link contains article metadata and directs it to the OpenURL server of your choice. The OpenURL server can provide access to the resource and also offer complementary services (specific search engine, export of references...). The OpenURL link can be generated by different means.

• If your librarian has set up your subscription with an OpenURL resolver, OpenURL links appear automatically on the abstract pages.
• You can define your own OpenURL resolver with your EDPS Account. In this case your choice will be given priority over that of your library.
• You can use an add-on for your browser (Firefox or I.E.) to display OpenURL links on a page (see http://www.openly.com/openurlref/). You should disable this module if you wish to use the OpenURL server that you or your library have defined.