University of Cambridge | 2015 Sep 04
A new method of measuring the distances between stars enables astronomers to climb the ‘cosmic ladder’ and understand the processes at work in the outer reaches of the galaxy.
[img3="Two ‘twin’ stars with identical spectra observed by the La Silla Telescope. Since it is known that one star is 40 parsecs away, the difference in their apparent brightnesses allows calculation of the second star’s distance. (Credit: Carolina Jofré)"]https://www.cam.ac.uk/sites/www.cam.ac. ... -web_0.png[/img3][hr][/hr]Astronomers from the University of Cambridge have developed a new, highly accurate method of measuring the distances between stars, which could be used to measure the size of the galaxy, enabling greater understanding of how it evolved.
Using a technique which searches out stellar ‘twins’, the researchers have been able to measure distances between stars with far greater precision than is possible using typical model-dependent methods. The technique could be a valuable complement to the Gaia satellite – which is creating a three-dimensional map of the sky over five years – and could aid in the understanding of fundamental astrophysical processes at work in the furthest reaches of our galaxy. Details of the new technique are published in the Monthly Notices of the Royal Astronomical Society.
“Determining distances is a key problem in astronomy, because unless we know how far away a star or group of stars is, it is impossible to know the size of the galaxy or understand how it formed and evolved,” said Dr Paula Jofre Pfeil of Cambridge’s Institute of Astronomy, the paper’s lead author. “Every time we make an accurate distance measurement, we take another step on the cosmic distance ladder.” ...
Climbing the cosmic ladder with stellar twins - P. Jofre et al
- Monthly Notices of the RAS 453(2):1428 (2015 Oct 21) DOI: 10.1093/mnras/stv1724
arXiv.org > astro-ph > arXiv:1505.07806 > 28 May 2015 (v1), 03 Sep 2015 (v2)