Saved in:
| Main Authors: | , , , , , , , , |
|---|---|
| Format: | Preprint |
| Published: |
2023
|
| Subjects: | |
| Online Access: | https://arxiv.org/abs/2312.17421 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866929195052957696 |
|---|---|
| author | Damineli, Augusto Richardson, Noel D. Navarete, Felipe Gull, Theodore. R. Fernández-Lajús, Eduardo Moffat, Anthony F. J. Hillier, Desmond J. Weigelt, Gerd Corcoran, Michael F. |
| author_facet | Damineli, Augusto Richardson, Noel D. Navarete, Felipe Gull, Theodore. R. Fernández-Lajús, Eduardo Moffat, Anthony F. J. Hillier, Desmond J. Weigelt, Gerd Corcoran, Michael F. |
| contents | Changes in the flux and spectrum of Eta Carinae since 1900 have been attributed to the evolution of the central binary by some. Others suggest evolution in the occulting ejecta. The brightness jump in the 1940s, which coincided with the appearance of narrow forbidden emission lines, may have been caused by the clearing and ionization of intervening circumstellar ejecta. The brightening changed at a slower pace up through forty years later. Here we continue earlier studies focused on the long-term showing that the forbidden line emission increased in the early 1990s with no noticeable increase in the brightness of the Homunculus. We interpret that the increase in narrow line emission is due to decreased extinction in the LOS from the central binary to the Weigelt clumps. In 2000, the central stellar core increased in brightness at a faster rate without associated changes in the Homunculus. By 2018, hundreds of narrow-line absorptions from singly-ionized metals in our LOS from Eta Carinae disappeared, thought to be caused by increased ionization of metals. These three events (1990, 2000, and 2018) are explained by the dissipation of circumstellar material within the Homunculus close to the binary. Combining these changes with the steadiness of the Homunculus and the primary winds over the past four decades indicates that circumstellar ejecta in our direction have been cleared. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2312_17421 |
| institution | arXiv |
| publishDate | 2023 |
| record_format | arxiv |
| spellingShingle | Long-term evolution in ionization of ejecta illuminated by Eta Carinae Damineli, Augusto Richardson, Noel D. Navarete, Felipe Gull, Theodore. R. Fernández-Lajús, Eduardo Moffat, Anthony F. J. Hillier, Desmond J. Weigelt, Gerd Corcoran, Michael F. Solar and Stellar Astrophysics Astrophysics of Galaxies Changes in the flux and spectrum of Eta Carinae since 1900 have been attributed to the evolution of the central binary by some. Others suggest evolution in the occulting ejecta. The brightness jump in the 1940s, which coincided with the appearance of narrow forbidden emission lines, may have been caused by the clearing and ionization of intervening circumstellar ejecta. The brightening changed at a slower pace up through forty years later. Here we continue earlier studies focused on the long-term showing that the forbidden line emission increased in the early 1990s with no noticeable increase in the brightness of the Homunculus. We interpret that the increase in narrow line emission is due to decreased extinction in the LOS from the central binary to the Weigelt clumps. In 2000, the central stellar core increased in brightness at a faster rate without associated changes in the Homunculus. By 2018, hundreds of narrow-line absorptions from singly-ionized metals in our LOS from Eta Carinae disappeared, thought to be caused by increased ionization of metals. These three events (1990, 2000, and 2018) are explained by the dissipation of circumstellar material within the Homunculus close to the binary. Combining these changes with the steadiness of the Homunculus and the primary winds over the past four decades indicates that circumstellar ejecta in our direction have been cleared. |
| title | Long-term evolution in ionization of ejecta illuminated by Eta Carinae |
| topic | Solar and Stellar Astrophysics Astrophysics of Galaxies |
| url | https://arxiv.org/abs/2312.17421 |