Scientists have fixed on the territory of the Small Magellanic Cloud a new metallic white post-symbiotic branch. The object was designated as J005252.87-722842.9 and is considered to have experienced an unusual evolutionary process.
For the first time, J005252.87-722842.9 was noticed in 2014 and noted a brightness of 8,000 solar. He was assigned to the post-AGB group. Such objects are at the stage of transition to a planetary nebula, because they evolved from an asymptotic giant branch due to rapid mass loss. But the phase after AGB is considered one of the least understood. Therefore, researchers are looking for similar objects for a detailed review. The new analysis shows that J005252 is an unusual representative in its development. It is believed that the third period failed. At this moment, the stellar photosphere is enriched with the products of internal nucleosynthesis (carbon, oxygen, nitrogen and heavy elements). But in this object did not notice such traces.
The UVES spectrograph at the Paranal Observatory helped examine the chemical composition that did not confirm carbon enhancement or enrichment with the listed elements. There is a thought that there is an unknown mechanism leading to AGB without dredging events. Further observations will help to solve the secret.