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Astronomers explore globular cluster NGC 2419

Using the Indian Astronomical Observatory (IAO) and ESA's Gaia satellite, astronomers have explored a galactic globular cluster known as NGC 2419. Results of the study, published April 29 on the preprint server arXiv, shed ...

New accreting millisecond X-ray pulsar discovered

Astronomers report the discovery of a new pulsar using the Spektr-RG space observatory. The newfound object, designated SRGA J144459.2−604207 (or SRGA J1444 for short), turns out to be a bursting accreting millisecond X-ray ...

Astronomers inspect open cluster Berkeley 50

Using the Lowell Discovery Telescope (LDT), astronomers from the Lowell Observatory in Flagstaff, Arizona, have observed a young Galactic open cluster known as Berkeley 50. Results of the observational campaign, presented ...

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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.

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