National Radio Astronomy Observatory | VLBA | 2017 Oct 12
[img3="Astronomers directly measured the distance to a region on the far side of our Milky Way Galaxy, past the Galaxy's center. Credit: Bill Saxton, NRAO/AUI/NSF; Robert Hurt, NASA"]https://public.nrao.edu/wp-content/uplo ... 70x600.jpg[/img3][hr][/hr]Astronomers using the National Science Foundation’s Very Long Baseline Array (VLBA) have directly measured the distance to a star-forming region on the opposite side of our Milky Way Galaxy from the Sun. Their achievement nearly doubles the previous record for distance measurement within our Galaxy. ...
Distance measurements are crucial for understanding the structure of the Milky Way. Most of our Galaxy’s material, consisting principally of stars, gas, and dust, lies within a flattened disk, in which our Solar System is embedded. Because we can’t see our Galaxy face-on, its structure, including the shape of its spiral arms, can only be mapped by measuring distances to objects elsewhere in the Galaxy.
The astronomers used a technique called trigonometric parallax, first used in 1838 to measure the distance to a star. This technique measures the apparent shift in the sky position of a celestial object as seen from opposite sides of the Earth’s orbit around the Sun. This effect can be demonstrated by holding a finger in front of one’s nose and alternately closing each eye — the finger appears to jump from side to side. ...
The Far Side of the Milky Way
Max Planck Institute for Radio Astronomy | 2017 Oct 12
Mapping spiral structure on the far side of the Milky Way - Alberto Sanna et al
- Science 358(6360):227 (13 Oct 2017) DOI: 10.1126/science.aan5452
arXiv.org > astro-ph > arXiv:1710.06489 > 17 Oct 2017