The cooling-down central star of the planetary nebula SwSt 1
- SwSt 1 (PN G001.5-06.7) is a bright and compact planetary nebula containing a late [WC]-type central star. Previous studies suggested that the nebular and stellar lines are slowly changing with time. We studied new and archival optical and ultraviolet spectra of the object. The [O III] 4959 and 5007 angstrom to H beta line flux ratios decreased between about 1976 and 1997/2015. The stellar spectrum also shows changes between these epochs. We modelled the stellar and nebular spectra observed at different epochs. The analyses indicate a drop of the stellar temperature from about 42 kK to 40.5 kK between 1976 and 1993. We do not detect significant changes between 1993 and 2015. The observations show that the star performed a loop in the H-R diagram. This is possible when a shell source is activated during its post-AGB evolution. We infer that a late thermal pulse (LTP) experienced by a massive post-AGB star can explain the evolution of the central star. Such a star does not expand significantly as the result of the LTP and does notSwSt 1 (PN G001.5-06.7) is a bright and compact planetary nebula containing a late [WC]-type central star. Previous studies suggested that the nebular and stellar lines are slowly changing with time. We studied new and archival optical and ultraviolet spectra of the object. The [O III] 4959 and 5007 angstrom to H beta line flux ratios decreased between about 1976 and 1997/2015. The stellar spectrum also shows changes between these epochs. We modelled the stellar and nebular spectra observed at different epochs. The analyses indicate a drop of the stellar temperature from about 42 kK to 40.5 kK between 1976 and 1993. We do not detect significant changes between 1993 and 2015. The observations show that the star performed a loop in the H-R diagram. This is possible when a shell source is activated during its post-AGB evolution. We infer that a late thermal pulse (LTP) experienced by a massive post-AGB star can explain the evolution of the central star. Such a star does not expand significantly as the result of the LTP and does not became a born-again red giant. However, the released energy can remove the tiny H envelope of the star.…
Author details: | Marcin HajdukORCiD, Helge Tobias TodtORCiD, Wolf-Rainer HamannORCiDGND, Karolina Borek, Peter A. M. van Hoof, Albert A. Zijlstra |
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DOI: | https://doi.org/10.1093/mnras/staa2274 |
ISSN: | 0035-8711 |
ISSN: | 1365-2966 |
Title of parent work (English): | Monthly notices of the Royal Astronomical Society |
Subtitle (English): | a late thermal pulse in a massive post-AGB star? |
Publisher: | Oxford Univ. Press |
Place of publishing: | Oxford |
Publication type: | Article |
Language: | English |
Date of first publication: | 2020/08/05 |
Publication year: | 2020 |
Release date: | 2024/01/10 |
Tag: | nebulae: general; planetary; planetary nebulae: individual: SwSt1; stars: AGB and post-AGB; stars: atmospheres; stars: evolution |
Volume: | 498 |
Issue: | 1 |
Number of pages: | 16 |
First page: | 1205 |
Last Page: | 1220 |
Funding institution: | Deutscher Akademischer Austauschdienst (DAAD)Deutscher Akademischer; Austausch Dienst (DAAD); Ministry of Science and Higher Education (MSHE); of the Republic of Poland; National Science Centre, PolandNational; Science Centre, Poland [2016/23/B/ST9/01653]; MSHE; [DIR/WK/2016/2017/05-1, 59/E383/SPUB/SP/2019.1]; European Southern; Observatory under ESO programmes [093.D-0182(A), 095.D-0953(A)]; Southern African Large Telescope (SALT) [2015-1-SCI-031]; [MSHE; DIR/WK/2016/07]; STFCUK Research & Innovation (UKRI)Science & Technology; Facilities Council (STFC) [ST/T000414/1] Funding Source: UKRI |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Physik und Astronomie |
DDC classification: | 5 Naturwissenschaften und Mathematik / 52 Astronomie / 520 Astronomie und zugeordnete Wissenschaften |
5 Naturwissenschaften und Mathematik / 53 Physik / 530 Physik | |
Peer review: | Referiert |