2019A&A...624A...1L


C.D.S. - SIMBAD4 rel 1.7 - 2019.11.14CET11:12:48

2019A&A...624A...1L - Astronomy and Astrophysics, volume 624A, 1-1 (2019/4-1)

Spectral analysis of the barium central star of the planetary nebula Hen 2-39.

LOBLING L., BOFFIN H.M.J. and JONES D.

Abstract (from CDS):


Context. Barium stars are peculiar red giants characterized by an overabundance of the elements synthesized in the slow neutron-capture nucleosynthesis (s-process elements) along with an enrichment in carbon. These stars are discovered in binaries with white dwarf companions. The more recently formed of these stars are still surrounded by a planetary nebula.
Aims. Precise abundance determinations of the various s-process elements, of further key elements that act as indicators for effectiveness of nucleosynthesis on the asymptotic giant branch and, especially, of the lightest, short-lived radionuclide technetium will establish constraints for the formation of s-process elements in asymptotic giant branch stars as well as mass transfer through, for example, stellar wind, Roche-lobe overflow, and common-envelope evolution.
Methods. We performed a detailed spectral analysis of the K-type subgiant central star of the planetary nebula Hen 2-39 based on high-resolution optical spectra obtained with the Ultraviolet and Visual Echelle Spectrograph at the Very Large Telescope using local thermodynamic equilibrium model atmospheres.
Results. We confirm the effective temperature of Teff=(4350±150)K for the central star of the planetary nebula Hen 2-39. It has a photospheric carbon enrichment of [C/H]=0.36±0.08 and a barium overabundance of [Ba/Fe]=1.8±0.5. We find a deficiency for most of the iron-group elements (calcium to iron) and establish an upper abundance limit for technetium (log eTc<2.5).
Conclusions. The quality of the available optical spectra is not sufficient to measure abundances of all s-process elements accurately. Despite large uncertainties on the abundances as well as on the model yields, the derived abundances are most consistent with a progenitor mass in the range 1.75-3.00M and a metallicity of [Fe/H]=-0.3±1.0. This result leads to the conclusion that the formation of such systems requires a relatively large mass transfer that is most easily obtained via wind-Roche lobe overflow.

Abstract Copyright: © ESO 2019

Journal keyword(s): planetary nebulae: individual: Hen 2-39 - stars: abundances - stars: evolution - stars: AGB and post-AGB - stars: chemically peculiar - binaries: general

Simbad objects: 8

goto Full paper

goto View the reference in ADS

Number of rows : 8

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2020
#notes
1 ACO 70 ClG 00 37 20 -07 25.5           ~ 8 0
2 WeBo 1 PN 02 40 14.3687650451 +61 09 16.782287585   16.25 14.45     K0III:pBa5CaIIem 31 1
3 HD 51959 SB* 06 59 10.0956577371 -07 06 32.024342810   10.05 8.92     K1IIIBa1 33 0
4 WRAY 16-64 PN 10 03 49.2045279660 -60 43 48.270869522     13.70     ~ 44 0
5 HD 88035 Pe* 10 08 41.9746196062 -20 18 49.637432236   10.24 9.14     G8pBa 23 0
6 PN LoTr 5 PN 12 55 33.7461986779 +25 53 30.561300806   9.72 8.88     G5III-IV 189 0
7 HD 121447 Pe* 13 55 46.9649688947 -18 14 56.480134690 11.50 9.61 7.80     C2,1_CH4:_Ba4 115 0
8 IRAS 19417+1701 PN 19 43 59.5110389170 +17 09 00.957899325   11.2   10.6   ~ 41 0

    Equat.    Gal    SGal    Ecl

To bookmark this query, right click on this link: simbad:objects in 2019A&A...624A...1L and select 'bookmark this link' or equivalent in the popup menu


2019.11.14-11:12:48

© Université de Strasbourg/CNRS

    • Contact