Related topics: galaxies · stars · black holes · nasa · astronomers

Oldest planetary debris in our galaxy found in new study

Astronomers led by the University of Warwick have identified the oldest star in our galaxy that is accreting debris from orbiting planetesimals, making it one of the oldest rocky and icy planetary systems discovered in the ...

Study investigates a rare Type Icn supernova

An international team of astronomers has conducted optical and near-infrared observations of a rare Type Icn supernova known as SN 2022ann. The results of the study, published November 9 on the preprint server arXiv, shed ...

Astronomers detect new Jupiter-like exoplanet

Using radial velocity measurements, astronomers from Japan and China have detected a new exoplanet orbiting a G-type giant star. The newfound alien world is similar in mass to Jupiter but much hotter than the solar system's ...

An ultra-short-period exoplanet discovered with TESS

Using NASA's Transiting Exoplanet Survey Satellite (TESS), an international team of astronomers has detected a new ultra-short-period exoplanet. The newfound alien world, designated HD 20329 b, orbits its host star in slightly ...

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Light-year

A light-year or light year (symbol: ly) is a unit of length, equal to just under 1013 kilometres. As defined by the International Astronomical Union (IAU), a light-year is the distance that light travels in a vacuum in one Julian year.

The light-year is often used to measure distances to stars and other distances on a galactic scale, especially in non-specialist and popular science publications. The preferred unit in astrometry is the parsec, because it can be more easily derived from, and compared with, observational data. The parsec is defined as the distance at which an object will appear to move one arcsecond of parallax when the observer moves one astronomical unit perpendicular to the line of sight to the observer, and is equal to approximately 3.26 light-years.

The related unit of the light-month, roughly one-twelfth of a light-year, is also used occasionally for approximate measures.

This text uses material from Wikipedia, licensed under CC BY-SA