2001A&A...365..465R


Query : 2001A&A...365..465R

2001A&A...365..465R - Astronomy and Astrophysics, volume 365, 465-475 (2001/1-3)

HD 172481: A super lithium-rich metal-deficient post-AGB binary with a red AGB companion.

REYNIERS M. and VAN WINCKEL H.

Abstract (from CDS):

We present in this paper a study on the peculiar supergiant HD 172481. Its spectral type (F2Ia), high galactic latitude (b=-10.37)° circumstellar dust, high radial velocity and moderate metal deficiency ([Fe/H]=-0.55) confirm the post-AGB character of this object. A detailed chemical analysis shows slight but real s-process overabundances, however no CNO-enhancement was detected. Furthermore, the spectral energy distribution and the TiO bands in the red part of the spectrum reveal a red luminous companion. The luminosity ratio of the hot F type component and this cool M type companion LF/LM is derived for a reddening of E(B-V)=0.44 (LF/LM ∼1.8) and indicates that the companion must also be strongly evolved and probably evolving along the AGB. Neither our photometric data-set, nor our radial velocity monitoring show evidence for orbital variability which may indicate that the period is too large for direct binary interaction. Most interestingly, a strong lithium resonance line is detected, which yields an abundance of logε(Li)=3.6. Several explanations for this large lithium content are explored.

Abstract Copyright:

Journal keyword(s): stars: abundances - binaries: spectroscopic - stars: chemically peculiar - stars: individual: HD 172481 - stars: AGB and post-AGB - stars: evolution

Simbad objects: 8

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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 - 2022
#notes
1 IRAS Z02229+6208 pA* 02 26 41.7882689568 +62 21 21.981286008   14.69 12.00 11.16 8.92 G8-K0_0-Ia: 53 0
2 * alf Lep V* 05 32 43.8161188 -17 49 20.241380 3.02 2.77 2.57 2.35 2.14 F0Ib 274 0
3 IRAS 05341+0852 pA* 05 36 55.0511076432 +08 54 08.656315452   15.37 13.45 12.95 11.43 F6I 109 0
4 HD 56126 pA* 07 16 10.2590823192 +09 59 47.954735376   9.20 8.32     F0/5Ia 310 0
5 IRAS 07430+1115 s*r 07 45 51.3968191368 +11 08 19.561606620   13.94 12.22 11.82 10.69 M2I 57 0
6 HD 302821 sg* 10 23 19.4847405144 -59 32 04.566918624   10.59 9.17     A7Ie 79 1
7 HD 172481 pA* 18 41 36.9595215744 -27 57 01.235714652   9.58 9.06     F2/3Ia 48 0
8 HD 235858 pA* 22 29 10.3748806056 +54 51 06.344572284   11.40 9.52 8.47 7.34 G5Ia 244 0

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2022.08.10-06:31:13

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