Doppler shifted transient sodium detection by KECK/HIRES
(2025) In Monthly Notices of the Royal Astronomical Society: Letters 540(1). p.48-53- Abstract
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 m s−1. . This is an improvement in RV stability of roughly 240 m s−1 with respect to the instrument standard. We report an average sodium flux residual of (Formula presented) per cent t (8.0σ) comparable to previous studies. Interestingly, an average Doppler shift of −6.2 ± 0.5 km s−1 (12.4 σ) is identified offset from the exoplanet rest frame. The velocity residuals in time trace a blueshift (Formula presented) to redshift (Formula presented) suggesting the origin of the observed sodium is unlikely from the atmosphere... (More)
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 m s−1. . This is an improvement in RV stability of roughly 240 m s−1 with respect to the instrument standard. We report an average sodium flux residual of (Formula presented) per cent t (8.0σ) comparable to previous studies. Interestingly, an average Doppler shift of −6.2 ± 0.5 km s−1 (12.4 σ) is identified offset from the exoplanet rest frame. The velocity residuals in time trace a blueshift (Formula presented) to redshift (Formula presented) suggesting the origin of the observed sodium is unlikely from the atmosphere of the planet. The average Na light curves indicate a depth of (Formula presented) per cent(11.7 σ) enduring ≲90 min with a half-max duration of $/sim$ 40.1 min. 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.
(Less)
- author
- organization
- publishing date
- 2025-06
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- exoplanets, planets and satellites: atmospheres, planets and satellites: composition, planets and satellites: gaseous planets, techniques: spectroscopic
- in
- Monthly Notices of the Royal Astronomical Society: Letters
- volume
- 540
- issue
- 1
- pages
- 48 - 53
- publisher
- Oxford University Press
- external identifiers
-
- scopus:105003840245
- ISSN
- 1745-3933
- DOI
- 10.1093/mnrasl/slaf031
- language
- English
- LU publication?
- yes
- id
- 78301b9c-f562-4da9-bbc8-9427576deefc
- date added to LUP
- 2025-07-29 09:20:52
- date last changed
- 2025-07-29 09:21:12
@article{78301b9c-f562-4da9-bbc8-9427576deefc, abstract = {{<p>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 m s<sup>−1</sup>. . This is an improvement in RV stability of roughly 240 m s<sup>−1</sup> with respect to the instrument standard. We report an average sodium flux residual of (Formula presented) per cent t (8.0σ) comparable to previous studies. Interestingly, an average Doppler shift of −6.2 ± 0.5 km s<sup>−1</sup> (12.4 σ) is identified offset from the exoplanet rest frame. The velocity residuals in time trace a blueshift (Formula presented) to redshift (Formula presented) suggesting the origin of the observed sodium is unlikely from the atmosphere of the planet. The average Na light curves indicate a depth of (Formula presented) per cent(11.7 σ) enduring ≲90 min with a half-max duration of $/sim$ 40.1 min. 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.</p>}}, author = {{Unni, Athira and Oza, Apurva V. and Hoeijmakers, H. Jens and Seidel, Julia V. and Sivarani, Thirupathi and Schmidt, Carl A. and Kesseli, Aurora Y. and de Kleer, Katherine and Baker, Ashley D. and Gebek, Andrea and Westram, Moritz Meyer zu and Fisher, Chloe and Sallum, Steph and Bestha, Manjunath and Bello-Arufe, Aaron}}, issn = {{1745-3933}}, keywords = {{exoplanets; planets and satellites: atmospheres; planets and satellites: composition; planets and satellites: gaseous planets; techniques: spectroscopic}}, language = {{eng}}, number = {{1}}, pages = {{48--53}}, publisher = {{Oxford University Press}}, series = {{Monthly Notices of the Royal Astronomical Society: Letters}}, title = {{Doppler shifted transient sodium detection by KECK/HIRES}}, url = {{http://dx.doi.org/10.1093/mnrasl/slaf031}}, doi = {{10.1093/mnrasl/slaf031}}, volume = {{540}}, year = {{2025}}, }