The weather report from IRC+10216: Evolving irregular clouds envelop carbon star

TL;DR

This study presents high-resolution near-infrared images of the carbon star IRC+10216 over eight years, revealing dynamic changes in its circumstellar environment and clarifying the star's obscured nature.

Contribution

It provides the first long-term high-resolution imaging of IRC+10216, showing substantial evolution and clarifying that the star is hidden beneath dust, not visible as bright spots.

Findings

Significant evolution of circumstellar features over 8 years

Previously identified bright spots do not contain the star

The star remains buried in dust and is not directly visible

Abstract

High angular resolution images of IRC+10216 are presented in several near infrared wavelengths spanning more than 8 years. These maps have been reconstructed from interferometric observations obtained at both Keck and the VLT, and also from stellar occultations by the rings of Saturn observed with the Cassini spacecraft. The dynamic inner regions of the circumstellar environment are monitored over eight epochs ranging between January 2000 and July 2008. The system is shown to experience substantial evolution within this period including the fading of many previously reported persistent features, some of which had been identified as the stellar photosphere. These changes are discussed in context of existing models for the nature of the underlying star and the circumstellar environment. With access to these new images, we are able to report that none of the previously identified bright spots in fact contain the star, which is buried in its own dust and not directly visible in the near infrared.