The Last Gasps of a Dying Star: ALMA Observations of the Pre-Planetary Nebula IRAS 06530-0213
Year: 2026
Type: preprint
Abstract: We present high angular-resolution ($\sim 0.{''}1 - 0.{''}5$) ALMA observations of millimeter-wave line and continuum emission (at $\sim0.44$ and $0.88$ mm) in the pre-planetary nebula IRAS 06530--0213 (IRAS 06530). These data show the presence of an extended circular ring -- first evidence of the last thermal-pulse preceding the post-AGB phase in a carbon star -- and a central bipolar nebula (CBN) and torus. The mass-loss rate of IRAS 06530's AGB progenitor decreased immediately after the thermal pulse, then rose again just before the post-AGB phase as evidenced by the presence of filamentary arc structures around the CBN. The arc stuctures are likely part of a 3-D Archimidean spiral structure generally attributed to the presence of a binary companion. But we do not find a compact continuum source at the location of IRAS 06530's central star, such as that associated with the compact dusty disks typically found in disk-prominent post-AGB objects known to have binary companions. The expansion ages derived for the torus and CBN imply that IRAS 06530's progenitor transitioned to a post-AGB star $\lesssim700$ yr ago. The molecular mass of the ejecta in IRAS 06530 is dominated by the filamentary arc region with a mass $M_{H_2}=(0.12-0.25) M_{\odot}$. Compared with solar values, the torus of IRAS 06530 appears to be significantly (modestly) enriched in $^{13}$C and $^{17}$O ($^{15}$N) as well -- a pattern of rare-isotope enrichment inconsistent with standard nucleosynthesis models. From the luminosity of IRAS 06530 and the age of its detached shell, while it was still on the AGB, we infer that the mass of IRAS 06530's progenitor was $(1.6-3.4) M_{\odot}$.
Source: arXiv (Cornell University)
Authors: Sahai, Raghvendra, Vlemmings, Wouter, Quintana-Lacaci, Guillermo, Kim, Hyosun, Alcolea, Javier, Balick, Bruce, Blackman, Eric G., Castro-Carrizo, Arancha, de Marco, Orsola, Kastner, Joel H., Lagadec, Eric, Lee, Chin-Fei, Santander-García, Miguel, Contreras, Carmen Sánchez, Ueta, Toshiya, Zijlstra, Albert A., Bujarrabal, Valentin, Sabin, Laurence, Tafoya, Daniel
Institutions: California Institute of Technology, Jet Propulsion Laboratory, Chalmers University of Technology, Consejo Superior de Investigaciones Científicas, Instituto de Física Fundamental, Korea Astronomy and Space Science Institute, Spanish National Observatory, University of Washington, University of Rochester, Institut de Radioastronomie Millimétrique, Macquarie University, Rochester Institute of Technology, Centre National de la Recherche Scientifique, Université Côte d'Azur, Lagrange Laboratory, Observatoire de la Côte d’Azur, Institute of Astronomy and Astrophysics, Academia Sinica, Academia Sinica, Centro de Astrobiología, University of Denver, University of Manchester, Universidad Nacional Autónoma de México
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funders: National Science Foundation, National Aeronautics and Space Administration, California Institute of Technology, Space Telescope Science Institute, National Radio Astronomy Observatory, Korea Astronomy and Space Science Institute, National Research Foundation of Korea, National Astronomical Observatory of Japan, Ministry of Science and ICT, South Korea, National Science and Technology Council, Jet Propulsion Laboratory, National Institutes of Natural Sciences, European Regional Development Fund, Agencia Estatal de Investigación
OpenAlex ID: W7214005251