เปรียบเทียบวิธี

	Strong Gravitational Lensing	Astrometry (Parallax)
สาขาวิชา	ดาราศาสตร์	ดาราศาสตร์
ตระกูล	Process / pipeline	Process / pipeline
ปีกำเนิด	1964	1838
ผู้ริเริ่ม	Sjur Refsdal	Friedrich Wilhelm Bessel
ประเภท	Observational measurement method	Astrometric distance measurement
แหล่งต้นตำรับ	Refsdal, S. (1964). On the possibility of determining Hubble's parameter and the masses of galaxies from the gravitational lens effect. Monthly Notices of the Royal Astronomical Society, 128(4), 307-311.	ESA (1997). The Hipparcos and Tycho Catalogues. Astrometric and photometric star catalogue. European Space Agency Technical Reports, SP-1200.
ชื่อเรียกอื่น	Strong Lensing, Gravitational Lens, Einstein Ring	Stellar Parallax, Trigonometric Parallax, Parallax Distance Method
ที่เกี่ยวข้อง	3	3
สรุป	Strong gravitational lensing occurs when massive objects (clusters, galaxies) bend light so strongly that multiple images of distant sources appear, or complete rings (Einstein rings) form. Proposed by Sjur Refsdal in 1964 and first observed in 0957+561 in 1979, strong lensing provides direct measurements of lens masses and cosmic distances independent of the distance ladder.	Astrometric parallax is the foundational geometric method for measuring distances to nearby stars, based on observing the apparent shift in a star's position as Earth orbits the Sun. First successfully demonstrated by Friedrich Wilhelm Bessel in 1838 for the star 61 Cygni, parallax remains the most direct and reliable distance measurement in astronomy, anchoring the entire cosmic distance ladder.