Phase retrieval applied to stellar occultation for asteroid silhouette characterization

Area of Science:

• Astronomy
• Astrophysics
• Planetary Science

Background:

• Stellar occultation is a key method for determining asteroid and moon sizes.
• Traditional methods provide nominal radius but fail to capture the complex shape due to diffraction effects.

Purpose of the Study:

• To develop an improved method for characterizing asteroid shapes using stellar occultation data.
• To address the limitations of traditional methods in low Fresnel number scenarios.

Main Methods:

• Inverting a Fresnel diffraction equation through a phase retrieval process.
• Utilizing data collected similarly to traditional occultation methods.
• Analyzing the impact of measurement noise on the reconstruction.

Main Results:

• A complete silhouette reconstruction of the occluding asteroid is achievable.
• The new method overcomes the limitations of traditional techniques for small near-Earth asteroids with low Fresnel numbers.
• Demonstrated practical application to asteroid 25143 Itokawa.

Conclusions:

• The developed phase retrieval method offers a comprehensive approach to asteroid shape characterization.
• This technique enhances the scientific value of stellar occultation events for small bodies research.