# Isotope shift and search for metastable superheavy elements in astrophysical data

## TL;DR

This paper investigates the spectral lines of heavy radioactive elements in astrophysical data, proposing they originate from decay of superheavy nuclei near the island of stability, and calculates isotope shifts to identify these isotopes.

## Contribution

It introduces calculations of isotope shifts for superheavy elements to aid in identifying metastable nuclei in astrophysical spectra, linking laboratory data with cosmic observations.

## Key findings

- Calculated isotope shifts for No, Lr, Nh, Fl, and Z=120.
- Identification of spectral lines potentially from N=184 isotopes.
- Support for the existence of metastable superheavy nuclei in space.

## Abstract

Spectral lines belonging to the short-lifetime heavy radioactive elements up to Es ($Z$=99) have been found in the spectra of the Przybylski's star. We suggest that these unstable elements may be decay products of a "magic" metastable nucleus belonging to the the island of stability where the nuclei have a magic number of neutrons $N=184$. The laboratory-produced nuclei have a significantly smaller number of neutrons. To identify spectra of the $N=184$ isotopes of these nuclei and their neutron-reach superheavy decay products in astrophysical data we calculate the isotope shift which should be added to the laboratory - measured wavelenghs. The results for the isotopic shifts in the strongest optical electromagnetic transitions in No, Lr, Nh, Fl,and $Z$=120 elements are presented.