HD 209458
HD 209458 · HIP 108859 · 47.0 pc · G0V · 1 confirmed planet
Section 01
General Information
HD 209458 b (Osiris) is a landmark object: the first exoplanet detected by the transit method (Henry et al. 2000; Charbonneau et al. 2000), and the first exoplanet with a detected atmosphere (Charbonneau et al. 2002 — Na detection from HST/STIS). Its host star is a near-solar twin, making it an excellent Codex target for chemical context to atmospheric observations.
Stellar Parameters
| Parameter | Symbol | Value | Source |
|---|---|---|---|
| Effective temperature | Teff | ~6117 K | Literature |
| Surface gravity | log g | ~4.36 | Literature |
| Metallicity | [Fe/H] | ~0.00 dex | Literature |
| Spectral type | — | G0V | Literature |
| Distance | d | 47.0 pc (153 ly) | Gaia DR3 |
Known Planets
| Planet | Mass | Type | Semi-major axis | Hab zone |
|---|---|---|---|---|
| Osiris (b) | 0.69 MJ | Hot Jupiter | 0.0471 AU | No — tidally locked |
Section 02
NASA Interactive Visualization
Section 04
Our Findings
Section 05
References & Credits
Key Literature
Henry et al. (2000), ApJ 529, L41 — transit discovery
Charbonneau et al. (2002), ApJ 568, 377 — first atmosphere
Vidal-Madjar et al. (2003) — hydrogen evaporation
Data Sources
NASA/IPAC Exoplanet Archive
SIMBAD / CDS — stellar parameters
Hipparcos / Gaia — parallax & distance
Image Credits
Credit: NASA/ESA — Artist concept of HD 209458 b (Osiris)
Interactive sky: CDS Aladin Lite v3 / DSS2
NASA Eyes: NASA/JPL-Caltech
Pipeline
HARPS S1D — ESO Science Archive
Analysis: The Exoplanet Codex