Changes

P Cygni is situated 10192.60 [[light year]]s from [[Earth]].<ref name=universeguide/> The star has mass between 50-60 solar masses and an extremely hot surface, estimated to have a temperature in excess of 19,400 kelvin.<ref name=illinois/> This high temeprature means it radiates somewhere between 500,000 to 900,000 times more energy than the [[Sun]].<ref name=illinois/> This puts its [[absolute magnitude]] at around -8.9, making it one of the brightest stars in the [[Milky Way|galaxy]].<ref>{{cite web|url=http://spider.seds.org/spider/Vars/pCyg.html|title=P Cygni|accessdate=December 29, 2021|publisher=spider.seds.org</ref> However our view is slightly dimmed by an intervening cloud of gas and dust. THe star is thought to be losing mass in the form of an intense [[stellar wind]] travelling at 300&nbsp;km/s.<ref name=illinois/> It is estimated to loose three hundred thousandths of a [[solar mass]] per year which is three million times more mass than the Sun looses in its own [[Solar wind]]. This complicates the observation of the star as light must pass through this wind on its way to Earth and the particles in the wind interfer with the light.

P Cygni is situated 10192.60 [[light year]]s from [[Earth]].<ref name=universeguide/> The star has mass between 50-60 solar masses and an extremely hot surface, estimated to have a temperature in excess of 19,400 kelvin.<ref name=illinois/> This high temeprature means it radiates somewhere between 500,000 to 900,000 times more energy than the [[Sun]].<ref name=illinois/> This puts its [[absolute magnitude]] at around -8.9, making it one of the brightest stars in the [[Milky Way|galaxy]].<ref>{{cite web|url=http://spider.seds.org/spider/Vars/pCyg.html|title=P Cygni|accessdate=December 29, 2021|publisher=spider.seds.org</ref> However our view is slightly dimmed by an intervening cloud of gas and dust. THe star is thought to be losing mass in the form of an intense [[stellar wind]] travelling at 300&nbsp;km/s.<ref name=illinois/> It is estimated to loose three hundred thousandths of a [[solar mass]] per year which is three million times more mass than the Sun looses in its own [[Solar wind]]. This complicates the observation of the star as light must pass through this wind on its way to Earth and the particles in the wind interfer with the light.

The star's brightness continues to change, increasing by around 15% per century caused by a reduction of the star's temperature by 6% per century.<ref name=illinois/> Although this means the total energy radiated by the star is reduced, it means less is emitted in the [[ultraviolet]] and instead radiated in the [[visible light|visible]]. There are still small fluctiations up and down, though only at most by 0.2 magnitudes.<ref name=aavso/> These variations can generally occur with a period of 0.156&nbsp;days or 3.75&nbsp;hours, though they can be fairly irregular and are thought to be due to possibly pulsation or flares on the star's surface.<ref name=universeguide/> P Cygni's fluctuation history place it in a very exclusive group of variable stars known as S&nbsp;Doradus star. Other members include [[Eta Carinae]] and [[S Doradus]] in the [[Magellanic Cloud]].

The star's brightness continues to change, increasing by around 15% per century caused by a reduction of the star's temperature by 6% per century.<ref name=illinois/> Although this means the total energy radiated by the star is reduced, it means less is emitted in the [[ultraviolet]] and instead radiated in the [[visible light|visible]]. There are still small fluctiations up and down, though only at most by 0.2 magnitudes.<ref name=aavso/> These variations can generally occur with a period of 0.156&nbsp;days or 3.75&nbsp;hours, though they can be fairly irregular and are thought to be due to possibly pulsation or flares on the star's surface.<ref name=universeguide/> P Cygni's fluctuation history place it in a very exclusive group of variable stars known as S&nbsp;Doradus star. Other members include [[Eta Carinae]] and [[S Doradus]] in the [[Magellanic Clouds]].

==References==

==References==