Artist’s concept of astronomers’ new direct measurement, looking past the Milky Way’s center, to the far side of our galaxy. Image via Bill Saxton, NRAO/AUI/NSF; Robert Hurt, NASA.
We can look billions of light-years away in space, and estimate the distances to faraway galaxies via their redshifts, but direct measurements are harder. Astronomers are getting better at direct measurements, though, and today (October 12, 2017) they announced they’ve used the Very Long Baseline Array (VLBA) to obtain a direct measurement to a star-forming region on the opposite side of our Milky Way. It’s impressive, and these astronomers said their achievement nearly doubles the previous record for distance measurement within the galaxy. Alberto Sanna, of the Max-Planck Institute for Radio Astronomy (MPIfR) in Germany said in a statement:
This means that, using the VLBA, we now can accurately map the whole extent of our galaxy.
These astronomers measured a distance of more than 66,000 light-years to a star-forming region called G007.47+00.05 on the opposite side of the Milky Way from our sun. The region is well past the galaxy’s center, which is some 27,000 light-years distant. The previous record for a parallax measurement was about 36,000 light-years. Sanna said:
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