Numerical simulations of the great eruption of η Carinae from the 1840s. I. Revisiting the explosion scenario
Abstract
In this work, we present new 2D hydrodynamical simulations of the major eruption of η Car in the 1840s, which resulted in the formation of a bipolar nebula that is commonly known as the large Homunculus. In our numerical models, we have included the high-speed component of 10 000 km s−1, which was detected in recent observations, providing direct evidence of an explosive event. Here, we investigate whether such a violent explosion is able to explain both the shape and the dynamical evolution of η Car's nebula. As in our previous work, we have assumed a two-stage scenario for η Car's eruption: a slow outflow phase for a few decades before the eruption, followed by the explosive event. From the collision of these outflow phases, the large Homunculus is produced. Our numerical simulations show that such a scenario does not resemble some of the observed physical features and the expansion of the nebula. Notwithstanding, we also explore other injection parameters (mass-loss rate and ejection velocity) for these outflow phases. In particular, we find that an explosion with an intermediate speed of 1000 km s−1 is able to reproduce the morphology and the kinematical age of the large Homunculus.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- March 2022
- DOI:
- 10.1051/0004-6361/202142020
- arXiv:
- arXiv:2112.03474
- Bibcode:
- 2022A&A...659A.168G
- Keywords:
-
- stars: individual: η Carinae;
- stars: winds;
- outflows;
- hydrodynamics;
- shock waves;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- Accepted to A&