Doppler Shifted Transient Sodium Detection by KECK/HIRES
Fuente:
arXiv
Saved in:
| Main Authors: | , , , , , , , , , , , , , , |
|---|---|
| Format: | Preprint |
| Published: |
2025
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866917982360305664 |
|---|---|
| author | Unni, Athira Oza, Apurva V. Hoeijmakers, H. Jens Seidel, Julia V. Sivarani, Thirupathi Schmidt, Carl A. Kesseli, Aurora Y. de Kleer, Katherine Baker, Ashley D. Gebek, Andrea Westram, Moritz Meyer zu Fisher, Chloe Sallum, Steph Bestha, Manjunath Bello-Arufe, Aaron |
| author_facet | Unni, Athira Oza, Apurva V. Hoeijmakers, H. Jens Seidel, Julia V. Sivarani, Thirupathi Schmidt, Carl A. Kesseli, Aurora Y. de Kleer, Katherine Baker, Ashley D. Gebek, Andrea Westram, Moritz Meyer zu Fisher, Chloe Sallum, Steph Bestha, Manjunath Bello-Arufe, Aaron |
| contents | We carried out the first high-resolution transit observations of the exoplanet WASP-49 Ab with Keck/HIRES. Upon custom wavelength calibration we achieve a Doppler RV precision of $<$ 60 ${\rm m\,s}^{-1}$. This is an improvement in RV stability of roughly 240 ${\rm m\,s}^{-1}$ with respect to the instrument standard. We report an average sodium flux residual of $Δ\mathcal{F}_{NaD}/ \mathcal{F}_{\star} (λ) \sim$ 3.2 $\pm$ 0.4 $\%$ (8.0 $σ$) comparable to previous studies. Interestingly, an average Doppler shift of -6.2 $\pm$ 0.5 ${\rm km\,s}^{-1}$ (12.4 $σ$) is identified offset from the exoplanet rest frame. The velocity residuals \textit{in time} trace a blueshift (v$_{Γ, ingress} \sim$ -10.3 $\pm$ 1.9 ${\rm km\,s}^{-1}$) to redshift (v$_{Γ, egress} \sim$ +4.1 $\pm$ 1.5 ${\rm km\,s}^{-1}$) suggesting the origin of the observed sodium is unlikely from the atmosphere of the planet. The average Na light curves indicate a depth of $Δ\mathcal{F}_{NaD} /\mathcal{F}_{\star} (t) \sim$ 0.47 $\pm$ 0.04 % (11.7 $σ$) enduring $\lesssim$ 90 minutes with a half-max duration of $\sim$ 40.1 minutes. Frequent high-resolution spectroscopic observations will be able to characterize the periodicity of the observed Doppler shifts. Considering the origin of the transient sodium gas is of unknown geometry, a co-orbiting natural satellite may be a likely source. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2504_03974 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Doppler Shifted Transient Sodium Detection by KECK/HIRES Unni, Athira Oza, Apurva V. Hoeijmakers, H. Jens Seidel, Julia V. Sivarani, Thirupathi Schmidt, Carl A. Kesseli, Aurora Y. de Kleer, Katherine Baker, Ashley D. Gebek, Andrea Westram, Moritz Meyer zu Fisher, Chloe Sallum, Steph Bestha, Manjunath Bello-Arufe, Aaron Earth and Planetary Astrophysics Instrumentation and Methods for Astrophysics Solar and Stellar Astrophysics We carried out the first high-resolution transit observations of the exoplanet WASP-49 Ab with Keck/HIRES. Upon custom wavelength calibration we achieve a Doppler RV precision of $<$ 60 ${\rm m\,s}^{-1}$. This is an improvement in RV stability of roughly 240 ${\rm m\,s}^{-1}$ with respect to the instrument standard. We report an average sodium flux residual of $Δ\mathcal{F}_{NaD}/ \mathcal{F}_{\star} (λ) \sim$ 3.2 $\pm$ 0.4 $\%$ (8.0 $σ$) comparable to previous studies. Interestingly, an average Doppler shift of -6.2 $\pm$ 0.5 ${\rm km\,s}^{-1}$ (12.4 $σ$) is identified offset from the exoplanet rest frame. The velocity residuals \textit{in time} trace a blueshift (v$_{Γ, ingress} \sim$ -10.3 $\pm$ 1.9 ${\rm km\,s}^{-1}$) to redshift (v$_{Γ, egress} \sim$ +4.1 $\pm$ 1.5 ${\rm km\,s}^{-1}$) suggesting the origin of the observed sodium is unlikely from the atmosphere of the planet. The average Na light curves indicate a depth of $Δ\mathcal{F}_{NaD} /\mathcal{F}_{\star} (t) \sim$ 0.47 $\pm$ 0.04 % (11.7 $σ$) enduring $\lesssim$ 90 minutes with a half-max duration of $\sim$ 40.1 minutes. Frequent high-resolution spectroscopic observations will be able to characterize the periodicity of the observed Doppler shifts. Considering the origin of the transient sodium gas is of unknown geometry, a co-orbiting natural satellite may be a likely source. |
| title | Doppler Shifted Transient Sodium Detection by KECK/HIRES |
| topic | Earth and Planetary Astrophysics Instrumentation and Methods for Astrophysics Solar and Stellar Astrophysics |
| url | https://arxiv.org/abs/2504.03974 |