Publications

Exploring the directly imaged HD 1160 system through spectroscopic characterization and high-cadence variability monitoring

The time variability and spectra of directly imaged companions provide insight into their physical properties and atmospheric dynamics. We find an effective temperature Teff = 2794+115−133 K on the first night, consistent with the literature, but a cooler Teff = 2279+79−157 K on the next. We estimate the mass of HD 1160 B to be 16-81 MJup, depending on its age. We also present R = 50 000 high-resolution optical spectroscopy of host star HD 1160 A obtained simultaneously with the PEPSI spectrograph. We reclassify its spectral type to A1 IV-V and measure its projected rotational velocity vsini = 96+6−4 km s-1. We thus highlight that gvAPP-enabled differential spectrophotometry can achieve repeatable few per cent level precision and does not yet reach a systematic noise floor, suggesting greater precision is achievable with additional data or advanced detrending techniques.

The left panel shows the PEPSI spectrum of the host star HD 1160 A in blue, overplotted with the best-fitting model from BT-Nextgen in orange. The fitting process was carried out for the region of the spectrum covering 392–429 nm. The contour plot in the right panel shows the χ2 distribution for several temperatures and vsini at fixed log(g) of 3.5.

Read more: Sutlieff et al. 2024, MNRAS, 531, 2168