2020A&A...638A..93R


Query : 2020A&A...638A..93R

2020A&A...638A..93R - Astronomy and Astrophysics, volume 638A, 93-93 (2020/6-1)

An in-depth reanalysis of the alleged type Ia supernova progenitor Henize 2-428.

REINDL N., SCHAFFENROTH V., MILLER BERTOLAMI M.M., GEIER S., FINCH N.L., BARSTOW M.A., CASEWELL S.L. and TAUBENBERGER S.

Abstract (from CDS):


Context. The nucleus of the planetary nebula Hen 2-428 is a short orbital-period (4.2 h), double-lined spectroscopic binary, whose status as a potential supernova type Ia progenitor has raised some controversy in the literature.
Aims. With the aim of resolving this debate, we carried out an in-depth reanalysis of the system.
Methods. Our approach combines a refined wavelength calibration, thorough line-identifications, improved radial-velocity measurements, non-LTE spectral modeling, as well as multi-band light-curve fitting. Our results are then discussed in view of state-of-the-art stellar evolutionary models.
Results. Besides systematic zero-point shifts in the wavelength calibration of the OSIRIS spectra which were also used in the previous analysis of the system, we found that the spectra are contaminated with diffuse interstellar bands. Our Voigt-profile radial velocity fitting method, which considers the additional absorption of these diffuse interstellar bands, reveals significantly lower masses (M1=0.66±0.11M and M2=0.42±0.07M) than previously reported and a mass ratio that is clearly below unity. Our spectral and light curve analyses lead to consistent results, however, we find higher effective temperatures and smaller radii than previously reported. Moreover, we find that the red-excess that was reported before to prove to be a mere artifact of an outdated reddening law that was applied.
Conclusions. Our work shows that blends of HeII λ 5412Å with diffuse interstellar bands have led to an overestimation of the previously reported dynamical masses of Hen 2-428. The merging event of Hen 2-428 will not be recognised as a supernova type Ia, but most likely leads to the formation of a H-deficient star. We suggest that the system was formed via a first stable mass transfer episode, followed by common envelope evolution, and it is now composed of a post-early asymptotic giant branch star and a reheated He-core white dwarf.

Abstract Copyright: © ESO 2020

Journal keyword(s): stars: individual: Hen 2-428 - binaries: spectroscopic - binaries: close - ISM: lines and bands

Simbad objects: 11

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Number of rows : 11
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2021
#notes
1 HD 21389 sg* 03 29 54.7426451518 +58 52 43.510657630 4.99 5.10 4.54 4.03 3.53 A0Ia 288 0
2 1ES 0439-68.2 CV* 04 39 49.64 -68 09 01.4   21.5 21.7     Ss 60 0
3 * alf Cam s*b 04 54 03.0103983 +66 20 33.636467 3.47 4.34 4.29 4.18 4.18 O9Ia 642 1
4 OGLE BRIGHT-LMC-ECL-9 SB* 05 38 28.4557395709 -69 11 19.134790412   14.28 14.485   14.385 O4.5V(n)((fc)):z:+O5.5V(n)((fc)):z: 23 0
5 PG 1501+664 WD* 15 02 09.6296551839 +66 12 19.146114550   16.07 16.37     DZQ1 151 0
6 CD-59 6479 Be* 17 16 21.08 -59 29 23.3 10.03 10.73 10.75     B3e 120 0
7 HD 170965 * 18 35 14.1777170405 -55 08 45.822674264   10.42 9.38     G8/K1 5 0
8 PN M 4-12 PN 19 13 05.239 +15 46 39.80           ~ 81 0
9 HD 183143 s*b 19 27 26.5636908636 +18 17 45.191198361 8.25 8.08 6.86 5.74 4.79 B6Ia 416 0
10 HD 190603 s*b 20 04 36.1744053423 +32 13 06.952102252 5.73 6.19 5.65 5.13 4.71 B1.5Ia 327 0
11 HD 204827 SB* 21 28 57.7601719555 +58 44 23.223287944 8.63 8.74 7.94 7.25 6.76 O9.5IV 316 0

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2021.07.30-00:56:16

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