Changes

Adhara's name comes from the [[Arabic]] "aðāra" or "Al Adhara" where it translates as "maidens".<ref name=constellation-guide>{{cite web|url=https://www.constellation-guide.com/constellation-list/canis-major-constellation/|title=Canis Major Constellation|accessdate=June 27, 2020|publisher=constellation-guide.com}}</ref>  

Adhara's name comes from the [[Arabic]] "aðāra" or "Al Adhara" where it translates as "maidens".<ref name=constellation-guide>{{cite web|url=https://www.constellation-guide.com/constellation-list/canis-major-constellation/|title=Canis Major Constellation|accessdate=June 27, 2020|publisher=constellation-guide.com}}</ref>  

It is not known who first called the star by this name, though the [[Egypt|Egyptian]] astronomer Al Achsasi al Mouakket refered to it as "Aoul al Adzari".<ref name=star-facts>{{cite web|url=https://www.star-facts.com/adhara/|title=ADHARA|accessdate=June 27, 2020|publisher=star-facts.com|date=September 25, 2019}}</ref> Sometimes the star is spelled slightly differently, various spellings include: Udra, Udara, Adard and Adara. The star is also known in [[Chinese]] as 弧矢七 (Hú Shǐ qī, Seventh Star of Bow and Arrow), where is is part of a Chinese [[asterism]] called the "Bow and Arrow". It is one of the 23 stars on the national flag of [[Brazil]], where it represents the Brazzilian state of Tocantins.

It is not known who first called the star by this name, though the [[Egypt]]ian astronomer Al Achsasi al Mouakket referred to it as "Aoul al Adzari".<ref name=star-facts>{{cite web|url=https://www.star-facts.com/adhara/|title=ADHARA|accessdate=June 27, 2020|publisher=star-facts.com|date=September 25, 2019}}</ref> Sometimes the star is spelled slightly differently, various spellings include: Udra, Udara, Adard and Adara. The star is also known in [[Chinese]] as 弧矢七 (Hú Shǐ qī, Seventh Star of Bow and Arrow), where it is part of a Chinese [[asterism]] called the "Bow and Arrow". It is one of the 23 stars on the national flag of [[Brazil]], where it represents the Brazzilian state of Tocantins.

==Properties and structure==

==Properties and structure==

The Epsilon Canis Majoris system can be found 405.17 [[light year]]s from [[Earth]].<ref name=star-facts/> The larger Epsilon Canis Majoris A is thought to have a [[mass]] of 12.6&nbsp;[[solar mass]]es and radius 13.9 times larger than the [[Sun]]'s. It possesses an apparent magnitude of +1.50 and a [[spectral class]] of B2. The star is though to rotate with an equatorial speed of 38&nbsp;km/s.<ref name=illinois/> With a surface temperature of 21,900&nbsp;kelvin, the star appears blue-white and is extremely luminous; it emits roughly 20,000 times more energy per second than the Sun.<ref name=space.com>{{cite web|url=https://www.space.com/22980-adhara.html|title=Adhara: Brightest Star in Ultraviolet Light|accessdate=June 27, 2020|publisher=space.com|author=Elizabeth Howell|date=Septermber 27, 2013}}</ref><ref name=astropixels>{{cite web|url=http://astropixels.com/stars/Adhara-01.html|title=Adhara|accessdate=June 27, 2020|publisher=astropixels.comdate=January 31, 2012}}</ref> The high temperature leads to large amounts of radiation emitted in the [[ultraviolet]] portion of the star's [[spectrum]]; it is 38.700 times brighter than the Sun here.<ref name=nineplanets>{{cite web|url=https://nineplanets.org/adhara-%CE%B5-canis-majoris/|title=Adhara (ε Canis Majoris) Facts|accessdate=June 27, 2020|publisher=nineplanets.org|date=January 30, 2020}}</ref> In fact is is known as an extreme ultraviolet source and was discovered by the Extreme Ultraviolet Explorer (EUVE) all-sky survey to be brighter than any other star in UV light, but as UV can't be seen by humans, it drops down to the 22^nd brightest star in the night sky. The UV light is able [[ionization|ionize]] [[hydrogen]] [[atom]]s and [[molecule]]s close to the star.<ref>{{cite web|url=https://ntrs.nasa.gov/search.jsp?R=19950064064|title=NASA Technical Reports Server (NTRS) - Epsilon Canis Majoris and the ionization of the local cloud|accessdate=June 27, 2020|publisher=ntrs.nasa.gov|work=Epsilon Canis Majoris and the ionization of the local cloud|date=May 10, 1995}}</ref> The star is used to determine the ionization state of the Local Interstellar Cloud as it is the strongest UV source near us.<ref name=nineplanets/> The cloud is 30&nbsp;ly across and our own [[Solar System]] is contained within it.

The Epsilon Canis Majoris system can be found 405.17 [[light year]]s from [[Earth]].<ref name=star-facts/> The larger Epsilon Canis Majoris A is thought to have a [[mass]] of 12.6&nbsp;[[solar mass]]es and radius 13.9 times larger than the [[Sun]]'s. It possesses an apparent magnitude of +1.50 and a [[spectral class]] of B2. The star is though to rotate with an equatorial speed of 38&nbsp;km/s.<ref name=illinois/> With a surface temperature of 21,900&nbsp;kelvin, the star appears blue-white and is extremely luminous; it emits roughly 20,000 times more energy per second than the Sun.<ref name=space.com>{{cite web|url=https://www.space.com/22980-adhara.html|title=Adhara: Brightest Star in Ultraviolet Light|accessdate=June 27, 2020|publisher=space.com|author=Elizabeth Howell|date=Septermber 27, 2013}}</ref><ref name=astropixels>{{cite web|url=http://astropixels.com/stars/Adhara-01.html|title=Adhara|accessdate=June 27, 2020|publisher=astropixels.comdate=January 31, 2012}}</ref> The high temperature leads to large amounts of radiation emitted in the [[ultraviolet]] portion of the star's [[spectrum]]; it is 38.700 times brighter than the Sun here.<ref name=nineplanets>{{cite web|url=https://nineplanets.org/adhara-%CE%B5-canis-majoris/|title=Adhara (ε Canis Majoris) Facts|accessdate=June 27, 2020|publisher=nineplanets.org|date=January 30, 2020}}</ref> In fact is known as an extreme ultraviolet source and was discovered by the Extreme Ultraviolet Explorer (EUVE) all-sky survey to be brighter than any other star in UV light, but as UV can't be seen by humans, it drops down to the 22^nd brightest star in the night sky. The UV light is able [[ionization|ionize]] [[hydrogen]] [[atom]]s and [[molecule]]s close to the star.<ref>{{cite web|url=https://ntrs.nasa.gov/search.jsp?R=19950064064|title=NASA Technical Reports Server (NTRS) - Epsilon Canis Majoris and the ionization of the local cloud|accessdate=June 27, 2020|publisher=ntrs.nasa.gov|work=Epsilon Canis Majoris and the ionization of the local cloud|date=May 10, 1995}}</ref> The star is used to determine the ionization state of the Local Interstellar Cloud as it is the strongest UV source near us.<ref name=nineplanets/> The cloud is 30&nbsp;ly across and our own [[Solar System]] is contained within it.

Less is known about the companion Epsilon Canis Majoris B. It is perhaps 250 times fainter than Epsilon Canis Majoris at a magnitude of +7.50, though some sources place it fainter still at +8 or even +9.<ref name=space.com/><ref name=illinois/> It is thought to have an [[absolute magnitude]] of +1.9.<ref name=star-facts/> Epsilon Canis Majoris B is hard to observe except with a large [[telescope]] as it is located only around 900 [[Astronomical unit]] or 7.5 [[arcsecond]]s away from Epsilon Canis Majoris A and Epsilon Canis Majoris A is so much brighter.<ref>{{cite web|url=https://www.daviddarling.info/encyclopedia/A/Adhara.html|title=Adhara (Epsilon Canis Majoris)|accessdate=June 27, 2020|publisher=daviddarling.info}}</ref>

Less is known about the companion Epsilon Canis Majoris B. It is perhaps 250 times fainter than Epsilon Canis Majoris at a magnitude of +7.50, though some sources place it fainter still at +8 or even +9.<ref name=illinois/><ref name=space.com/> It is thought to have an [[absolute magnitude]] of +1.9.<ref name=star-facts/> Epsilon Canis Majoris B is hard to observe except with a large [[telescope]] as it is located only around 900 [[Astronomical unit]] or 7.5 [[arcsecond]]s away from Epsilon Canis Majoris A and Epsilon Canis Majoris A is so much brighter.<ref>{{cite web|url=https://www.daviddarling.info/encyclopedia/A/Adhara.html|title=Adhara (Epsilon Canis Majoris)|accessdate=June 27, 2020|publisher=daviddarling.info}}</ref>

==References==

==References==