Table · dataset · 2025
WASP-121b radial velocities from JWST NIRSpec
Listed in IVOA Registry (Virtual Observatory)
We have conducted a planetary radial velocity measurement of the ultrahot Jupiter WASP-121b using JWST NIRSpec phase curve data.
Description
Our analysis reveals the Doppler shift of the planetary spectral lines across the full orbit, which shifts considerably across the detector (~10 pixels). Using cross-correlation techniques, we have determined an overall planetary velocity amplitude of K_p_=215.7+/-1.1km/s, which is in good agreement with the expected value.
We have also calculated the dynamical mass for both components of the system by treating it as an eclipsing double-line spectroscopic binary, with WASP-121A having a mass of M_s_=1.330+/-0.019M_{sun}_, while WASP-121b has a mass of M_p_=1.170+/-0.043M_J_. These dynamical measurements are ~3x more precise than previous estimates and do not rely on any stellar modeling assumptions that have a ~5% systematic floor mass uncertainty.
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Additionally, we used stellar evolution modeling constrained with a stellar density and parallax measurement to determine a precise age for the system, found to be 1.11+/-0.14Gyr. Finally, we observed potential velocity differences between the two NIRSpec detectors, with NRS1 lower by 5.5+/-2.2km/s. We suggest that differences can arise from day/night asymmetries in the thermal emission, which can lead to a sensitivity bias favoring the illuminated side of the planet, with planetary rotation and winds both acting to lower a measured K_p_.
The planet's rotation can account for 1km/s of the observed velocity difference, with 4.5+/-2.2km/s potentially attributable to vertical differences in wind speeds.
Links
Where it is published
- Reference page cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/168/231 ↗
landing page · from IVOA Registry
Documentation and papers
- ADS 2024AJ....168..231S ui.adsabs.harvard.edu/abs/2024AJ....168..231S ↗
publication · from IVOA Registry
Catalogue records · 2
- VOResource record dc.g-vo.org/oai.xml?verb=GetRecord&metadataPrefix=ivo_vor&identifier=ivo%3… ↗
metadata API · from IVOA Registry
- Registry record (GAVO) dc.g-vo.org/I/cds.vizier/j/aj/168/231 ↗
catalogue entry · from IVOA Registry
Topics
- Stated by source
- Infrared
- From keywords
- Astronomy & Astrophysics
- Inferred from text
- Stellar astronomy and planetary systems 76%
Provenance · 1 source records, 9 field assertions
| Source | Key | Last seen | Raw |
|---|---|---|---|
| IVOA Registry (Virtual Observatory) | ivo://cds.vizier/j/aj/168/231 | 12 d ago | JSON v1 |
| Field | Assertion | Extractor | Evidence |
|---|---|---|---|
| access_level | source · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| concepts[field].anzsrc:field:510109 | enrichment · IVOA Registry | taxonomy-embedding@1.1.0 | title+keywords+description (76%) |
| concepts[field].local:field:astronomy | mapping · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| concepts[modality].ivoa_waveband:infrared | source · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| description | source · IVOA Registry | connector:ivoa_registry@1.0.0 | rr.resource.res_description |
| license_text | source · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| publication_date | source · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| title | source · IVOA Registry | connector:ivoa_registry@1.0.0 | rr.resource.res_title |
| updated_date | source · IVOA Registry | connector:ivoa_registry@1.0.0 |