SWhat changed
Marois and colleagues used high-contrast near-infrared imaging at Gemini and Keck to resolve three faint companions of HR 8799. Multi-epoch positions supported common motion with the star and apparent orbital motion, while their colors and luminosities, together with a young system age and evolutionary models, supported planetary-mass interpretations. A later five-author report added images and measured motion of a fourth, closer companion, HR 8799 e.
Scientific scope
Marois and colleagues used high-contrast near-infrared imaging at Gemini and Keck to resolve three faint companions of HR 8799. Multi-epoch positions supported common motion with the star and apparent orbital motion, while their colors and luminosities, together with a young system age and evolutionary models, supported planetary-mass interpretations. A later five-author report added images and measured motion of a fourth, closer companion, HR 8799 e. The original three reported separations and the fourth companion separation are projected distances, not directly measured orbital semimajor axes. Original orbital periods assumed circular, nearly face-on orbits. Stellar age, atmosphere models and initial conditions of evolutionary tracks affect inferred masses; the authors noted atmosphere models did not fit all photometry. The fourth companion had sparse wavelength coverage, so its luminosity and mass were inferred using assumptions informed by other companions. A preliminary stability search held the other orbits fixed and tested selected parameters; its few stable solutions do not establish a unique resonance or global stability. The images use starlight-subtraction processing and calibrated throughput; planetary surfaces are not resolved. The 2008 and 2010 reports have distinct bylines and observation sets.
Evidence
The linked original works support the scoped statement and contribution attribution. WRS has not independently replayed experiments or reconstructed a full mathematical proof. The original three reported separations and the fourth companion separation are projected distances, not directly measured orbital semimajor axes. Original orbital periods assumed circular, nearly face-on orbits. Stellar age, atmosphere models and initial conditions of evolutionary tracks affect inferred masses; the authors noted atmosphere models did not fit all photometry. The fourth companion had sparse wavelength coverage, so its luminosity and mass were inferred using assumptions informed by other companions. A preliminary stability search held the other orbits fixed and tested selected parameters; its few stable solutions do not establish a unique resonance or global stability. The images use starlight-subtraction processing and calibrated throughput; planetary surfaces are not resolved. The 2008 and 2010 reports have distinct bylines and observation sets.
Contributors
- The named authors in the research record · SCIENCE: These are the listed authors of the cited contribution sources. Paper authorship does not quantify individual effort. An incomplete list is explicitly marked; same names are not automatically merged.
- Direct Imaging of Multiple Planets Orbiting the Star HR 8799
- Images of a fourth planet orbiting HR 8799
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