THE "BORE HOLE" IN ETA CARINAE AROUND THE 2025.7 PERIASTRON

• Grant number: 24/16086-6
• Support Opportunities: Regular Research Grants
• Start date: April 01, 2025
• End date: March 31, 2028
• Field of knowledge: Physical Sciences and Mathematics - Astronomy - Stellar Astrophysics
• Principal Investigator: Augusto Damineli Neto
• Grantee: Augusto Damineli Neto
• Host Institution: Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

We plan to carry out photometric monitoring of eta Carinae in the period 2025-27 to characterize the "bore hole" phenomenon, which should reach its highest amplitude in the historical series in 2025.7. This is a new phenomenon in Astrophysics that has not yet been adequately characterized either observationally or theoretically. We present a summarized view of the scientific justification and parameters regarding observational procedures. Paschen series lines will be used to accurately model the Keplerian motion of the primary star. Several spectral lines will be used in comparison with previous periastrons to characterize long-term changes and predict when the occultator will finish dissipating. In collaboration with other researchers, we will use this data to better characterize the geometric parameters of wind collision in 3D. This data will be used to revisit the work we have published since 1997, now with better precision. We present the observational campaign based on 4 telescopes for spectroscopy and 4 for photometry. (AU)