Gravitational Starlight Deflection Measurements during the 21 August 2017 Total Solar Eclipse

Abstract

Precise starlight positions near the sun were measured during the 21 August 2017 total solar eclipse in order to measure their gravitational deflections. The equipment, procedures, and analysis are described in detail. A portable refractor, a CCD camera, and a computerized mount were set up in Wyoming. Detailed calibrations were necessary to improve accuracy and precision. Nighttime measurements taken just before the eclipse provided cubic optical distortion corrections. Calibrations based on star field images 7.4 deg on both sides of the sun taken during totality gave linear and quadratic plate constants. A total of 45 images of the sky surrounding the Sun were acquired during the middle part of totality, with an integrated exposure of 22 seconds. The deflection analysis depended on accurate star positions from the USNO's UCAC5 star catalog. The final result was a deflection coefficient L = 1.752 arcsec, compared to the theoretical value of L = 1.751 arcsec, with an uncertainty of only 3%.

arXiv comment21 pages, 11 figures, 6 tables. Submitted to Classical and Quantum Gravity

References in corpus (4)

• Gaia Data Release 1: Astrometry - one billion positions, two million proper motions and parallaxes
• UCAC5: New Proper Motions using Gaia DR1
• Gaia Data Release 1: The reference frame and the optical properties of ICRF sources
• Measuring the Atmospheric Influence on Differential Astrometry: a Simple Method Applied to Wide Field CCD Frames

Cited by in corpus (4)

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• Strong-field gravitational lensing by black holes
• A Century of Light-Bending Measurements: Bringing Solar Eclipses into the Classroom
• On planetary orbits, ungravity and entropic gravity