A&A 452, 503-510 (2006)
DOI: 10.1051/0004-6361:20054190
The effect of dust obscuration in RR Telescopii on optical and IR long-term photometry and Fe II emission lines
D. Kotnik-Karuza1, M. Friedjung2, P. A. Whitelock3, F. Marang3, K. Exter4, F. P. Keenan5 and D. L. Pollacco51 Physics Department, Faculty of Arts and Sciences, Omladinska 14, 51000 Rijeka, Croatia
e-mail: dubravka.karuza-kotnik@ri.htnet.hr
2 Institut d'Astrophysique de Paris UMR7075 CNRS, Université Pierre & Marie Curie, 98 bis Boulevard Arago, 75014 Paris, France
e-mail: friedjung@iap.fr
3 South African Astronomical Observatory, Observatory, South Africa and national Astrophysics and Space Science Programme, University of Cape Town, 7701 Rondebosch, South Africa
e-mail: paw@saao.ac.za
4 Instituto de Astrofisica de Canarias, La Laguna (Tenerife), Spain
e-mail: katrina@iac.es
5 Dept. of pure and applied physics, Queens University, Belfast, Northern Ireland
e-mail: F.Keenan@qub.ac.uk
(Received 12 September 2005 / Accepted 19 January 2006)
Abstract
Aims.Infrared and optical photometric and spectroscopic observations of the
symbiotic nova RR Tel are used to study the effects and properties of dust in
symbiotic binaries containing a cool Mira component, as well as showing "obscuration events"
of increased absorption, which are typical for such Miras.
Methods.A set of photometric observations of the symbiotic nova
RR Tel
in different wavelength bands - visual from 1949 to 2002 and
near-infrared (
) from 1975 to 2002 - are presented. The
variability due to the normal Mira pulsation was removed from the
JHKL data, which were then compared with the American Association
of Variable Star Observers' (
) visual light curve. The
changes of the Fe II emission line fluxes during the 1996-2000
obscuration episode were studied in the optical spectra taken with
the Anglo-Australian telescope.
Results.We discuss the three periods during which the Mira component was
heavily obscured by dust as observed in the different wavelength
bands. A change in the correlations of J with other infrared
magnitudes was observed with the colour becoming redder after
JD 2 446 600. Generally, J-K was comparable, while K-L was larger
than typical values for single Miras. A distance estimate of 2.5 kpc, based on the IR data, is given. A larger flux decrease for
the permitted than for the forbidden Fe II lines, during the
obscuration episode studied, has been found. There is no evidence
for other correlations with line properties, in particular with
wavelength, which suggests obscuration due to separate optically
thick clouds in the outer layers.
Key words: stars: binaries: symbiotic -- stars: individual: RR Tel -- stars: circumstellar matter
SIMBAD Objects
Tables at the CDS
© ESO 2006

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