Vol. 595
In section 7. Stellar structure and evolution

Dissecting a supernova impostor's circumstellar medium: MUSEing about the SHAPE of eta Carinae's outer ejecta

by A. Mehner, W. Steffen, J.H. Groh, et al. A&A 595, A120

The authors have carried out the first large-scale integral field unit observations of η Car in the optical, using the Multi Unit Spectroscopic Explorer (MUSE) at the Very Large Telescope (VLT). They then performed morpho-kinematic modeling of these ejecta with the code SHAPE. They find that the largest coherent structure in η Car’s outer ejecta can be described as a bent cylinder with roughly the same symmetry axis as the Homunculus nebula. This large outer shell is interacting with the surrounding medium, creating soft X-ray emission. The authors establish the shape and extent of the ghost shell in front of the southern Homunculus lobe, which suggests a sequence of eruptions within the time frame of the Great Eruption from 1837–1858, and confirm that the NN condensation can best be modeled as a bowshock in the orbital/equatorial plane.