Volume 509, January 2010
|Number of page(s)||9|
|Section||Stellar structure and evolution|
|Published online||12 January 2010|
High- and low-resolution spectroscopic observations of the peculiar planetary-nebula HD 149427 (=PC 11) *,**
Observatório Nacional-MCT, Rua José Cristino, 77. CEP 20921-400 São Cristóvão, Rio de Janeiro-RJ, Brazil e-mail: [claudio;baella;daflon]@on.br
2 Instituto de Astrofísica de Andalucía, CSIC, Apdo. 3004, 18080 Granada, Spain e-mail: email@example.com
Accepted: 5 August 2009
Aims. We discuss the status of the A-type component of the binary central star in the peculiar planetary nebula HD 149427.
Methods. We acquired low and high spectral resolution optical spectroscopy for the range 4500-9000 Å.
Results. The analysis of the high resolution spectrum shows that the A-type star has an effective temperature of = 8700 ± 150 K and a surface gravity of log g = 2.3 ± 0.4, corresponding to a spectral type A3-A4 II. These parameters infer a luminosity estimate of = 3.69 ± 0.32, implying a distance of 10 ± 0.6 kpc. The A-type star is slightly metal-poor; barium and strontium, two key elements for monitoring the s-process nucleosynthesis, are not enriched; nitrogen is enriched relative to Sun; while carbon and oxygen are underabundant. The photospheric abundance of the A-type giant star in HD 149427 is compared with the abundance in other types of stars at different evolutionary stages.
Key words: planetary nebulae: individual: HD 149427 / stars: abundances / stars: fundamental parameters
© ESO, 2010
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.