The new carbon symbiotic star IPHAS J205836.43+503307.2
Autor: | Ulisse Munari, Romano L. M. Corradi, Robert Greimel, A. Englaro, G. Cetrulo, R. Angeloni, Antonio Mampaso, Laurence Sabin |
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Rok vydání: | 2011 |
Předmět: |
Physics
FOS: Physical sciences Astronomy and Astrophysics Astrophysics Galactic plane Galaxy Carbon star Photometry (optics) Stars Astrophysics - Solar and Stellar Astrophysics Space and Planetary Science Symbiotic star Circumstellar dust Emission spectrum Solar and Stellar Astrophysics (astro-ph.SR) |
Zdroj: | Astronomy & Astrophysics Artículos CONICYT CONICYT Chile instacron:CONICYT ASTRONOMY & ASTROPHYSICS |
ISSN: | 1432-0746 0004-6361 |
DOI: | 10.1051/0004-6361/201016406 |
Popis: | We are performing a search for symbiotic stars using IPHAS, the INT Halpha survey of the northern Galactic plane, and follow-up observations. Candidate symbiotic stars are selected on the basis of their IPHAS and near-IR colours, and spectroscopy and photometry are obtained to determine their nature. We present here observations of the symbiotic star candidate IPHAS J205836.43+503307.2. The optical spectrum shows the combination of a number of emission lines, among which are the high-excitation species of [OIII], HeII, [Ca V], and [Fe VII], and a red continuum with the features of a star at the cool end of the carbon star sequence. The nebular component is spatially resolved: the analysis of the spatial profile of the [NII]6583 line in the spectrum indicates a linear size of ~2.5 arcsec along the east-west direction. Its velocity structure suggests an aspherical morphology. The near-infrared excess of the source, which was especially strong in 1999, indicated that a thick circumstellar dust shell was also present in the system. The carbon star has brightened in the last decade by two to four magnitudes at red and near-infrared wavelengths. Photometric monitoring during a period of 60 days from November 2010 to January 2011 reveals a slow luminosity decrease of 0.2 magnitudes. From the observed spectrophotometric properties and variability, we conclude that the source is a new Galactic symbiotic star of the D-type, of the rare kind that contains a carbon star, likely a carbon Mira. Only two other systems of this type are known in the Galaxy. 6 pages, 4 figures |
Databáze: | OpenAIRE |
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