Related papers: A new study of $^{25}$Mg($\alpha$,n)$^{28}$Si angu…
Gamma-ray line observations provide a versatile tool for studies of nucleosynthesis processes and supernova physics. In particular, the observation of radioactive species in the interstellar medium probes recent nucleosynthesis activity on…
Massive stars are one of the most important and investigated astrophysical production sites of $^{26}$Al, a short-lived radioisotope with $\sim$ 1 Myr half-life. Its short lifetime prevents us from observing its complete chemical history,…
The $\mathrm{^{25}Al(p,\gamma)^{26}Si}$ reaction is part of a reaction network with impact on the observed galactic $^{26}$Al abundance. A new determination of the proton strength of the lowest $\ell=0$ proton-resonance in $^{26}$Si is…
Massive stars are a major source of chemical elements in the cosmos, ejecting freshly produced nuclei through winds and core-collapse supernova explosions into the interstellar medium. Among the material ejected, long lived radioisotopes,…
The $^{22}$Mg($\alpha$,$p$)$^{25}$Al reaction rate has been identified as a major source of uncertainty for understanding the nucleosynthesis flow in Type-I x-ray bursts (XRBs). We report a direct measurement of the energy- and…
Hans Bethe contributed in many ways to our understanding of the supernovae that happen in massive stars, but, to this day, a first principles model of how the explosion is energized is lacking. Nevertheless, a quantitative theory of…
The stars in globular clusters are known to differ in their surface chemistry: the spectroscopic investigations in the last decades outlined the presence of star-to-star differences in the abundances of the light elements, up to aluminium…
26Al is a short-lived radioactive isotope thought to be injected into the interstellar medium (ISM) by massive stellar winds and supernovae. However, all-sky maps of 26Al emission show a distribution with a much larger scale height and…
Stardust is a class of presolar grains each of which presents an ideally uncontaminated stellar sample. Mainstream silicon carbide (SiC) stardust formed in the extended envelopes of carbon-rich asymptotic giant branch (AGB) stars and…
Diffuse gamma-ray emission from the decay of radioactive $^{26}$Al is a messenger from the nucleosynthesis activity in our current-day galaxy. Because this material is attributed to ejections from massive stars and their supernovae, the…
The cosmic evolution of the chemical elements from the Big Bang to the present time is driven by nuclear fusion reactions inside stars and stellar explosions. A cycle of matter recurrently re-processes metal-enriched stellar ejecta into the…
Decades ago, $\gamma$-ray observatories identified diffuse Galactic emission at 1.809 MeV originating from $\beta^+$ decays of an isotope of aluminium, $^{26}$Al, that has a mean-life time of 1.04 Myr. Objects responsible for the production…
The astrophysical $s$-process is one of the two main processes forming elements heavier than iron. A key outstanding uncertainty surrounding $s$-process nucleosynthesis is the neutron flux generated by the ${}^{22}\mathrm{Ne}(\alpha,…
The current status of the reaction rate of $^{22}$Ne($\alpha$,n)$^{25}$Mg is summarized. Among the latest new results, probably the most relevant is the conclusion that the E$_x$=11.15 MeV state in $^{26}$Mg has a non-natural parity, so it…
The isotopes $^{60}$Fe and $^{26}$Al originate from massive stars and their supernovae, reflecting ongoing nucleosynthesis in the Galaxy. We studied the gamma-ray emission from these isotopes at characteristic energies 1173, 1332, and 1809…
Over the last three years, the rates of all the main nuclear reactions involving the destruction and production of $^{26}$Al in stars ($^{26}$Al(n, p)$^{26}$Mg, $^{26}$Al(n, $\alpha$)$^{23}$Na, $^{26}$Al(p, $\gamma$)$^{27}$Si and…
Using recently calculated yields for Type II supernovae, along with models for chemical evolution and the distribution of mass in the interstellar medium, the current abundances and spatial distributions of two key gamma-ray…
Context. The diffuse gamma-ray emission of $^{26}{\rm Al}$ at 1.8 MeV reflects ongoing nucleosynthesis in the Milky Way, and traces massive-star feedback in the interstellar medium due to its 1 Myr radioactive lifetime. Interstellar-medium…
We study the effect of uncertainties in the proton-capture reaction rates of the NeNa and MgAl chains on nucleosynthesis due to the operation of hot bottom burning (HBB) in intermediate-mass asymptotic giant branch (AGB) stars. HBB…
The competing $^{22}$Ne($\alpha,\gamma$)$^{26}$Mg and $^{22}$Ne($\alpha,n$)$^{25}$Mg reactions control the production of neutrons for the weak $s$-process in massive and AGB stars. In both systems, the ratio between the corresponding…