by APOD Robot » Fri Mar 18, 2016 4:15 am
The W in Cassiopeia
Explanation: A familiar, zigzag, W pattern in northern
constellation Cassiopeia is traced by five bright stars in this colorful and broad mosaic. Stretching about 15 degrees across rich starfields, the celestial scene
includes dark clouds,
bright nebulae, and
star clusters along the Milky Way. In yellow-orange hues Cassiopeia's
alpha star Shedar is a standout though. The yellowish giant star is cooler than the Sun, over 40 times the solar diameter, and so luminous it shines brightly in Earth's night from 230 light-years away. A massive, rapidly rotating star at the center of the W, bright
Gamma Cas is about 550 light-years distant. Bluish Gamma Cas is much hotter than the Sun. Its intense, invisible ultraviolet radiation ionizes hydrogen atoms in
nearby interstellar clouds to produce visible red H-alpha emission as the atoms recombine with electrons.
Of course, night skygazers in the Alpha Centauri star system would also see the recognizable outline traced by Cassiopeia's bright stars. But
from their perspective a mere 4.3 light-years away they would see our Sun as a sixth bright star in Cassiopeia, extending the zigzag pattern just beyond the left edge of this frame.
[/b]
[url=http://apod.nasa.gov/apod/ap160318.html][img]http://apod.nasa.gov/apod/calendar/S_160318.jpg[/img] [size=150]The W in Cassiopeia[/size][/url]
[b] Explanation: [/b] A familiar, zigzag, W pattern in northern [url=https://en.wikipedia.org/wiki/Cassiopeia_%28constellation%29]constellation Cassiopeia[/url] is traced by five bright stars in this colorful and broad mosaic. Stretching about 15 degrees across rich starfields, the celestial scene [url=http://www.nasa.gov/mission_pages/chandra/multimedia/exploring-cassiopeiaA.html]includes[/url] dark clouds, [url=http://apod.nasa.gov/apod/ap141128.html]bright nebulae[/url], and [url=http://apod.nasa.gov/apod/ap010207.html]star clusters[/url] along the Milky Way. In yellow-orange hues Cassiopeia's [url=http://stars.astro.illinois.edu/sow/shedar.html]alpha star Shedar[/url] is a standout though. The yellowish giant star is cooler than the Sun, over 40 times the solar diameter, and so luminous it shines brightly in Earth's night from 230 light-years away. A massive, rapidly rotating star at the center of the W, bright [url=http://stars.astro.illinois.edu/sow/gammacas.html]Gamma Cas is[/url] about 550 light-years distant. Bluish Gamma Cas is much hotter than the Sun. Its intense, invisible ultraviolet radiation ionizes hydrogen atoms in [url=http://apod.nasa.gov/apod/ap091224.html]nearby interstellar[/url] clouds to produce visible red H-alpha emission as the atoms recombine with electrons. [url=http://apod.nasa.gov/apod/ap121018.html]Of course, night skygazers[/url] in the Alpha Centauri star system would also see the recognizable outline traced by Cassiopeia's bright stars. But [url=http://telescopium.org/Alpha_C.html]from their perspective[/url] a mere 4.3 light-years away they would see our Sun as a sixth bright star in Cassiopeia, extending the zigzag pattern just beyond the left edge of this frame.
[b][table][tr][td=left][url=http://asterisk.apod.com/discuss_apod.php?date=160317]<< Previous APOD[/url][/td] [td=center][url=http://asterisk.apod.com/view_retro.php?date=0318]This Day in APOD[/url][/td] [td=right][url=http://asterisk.apod.com/discuss_apod.php?date=160319]Next APOD >>[/url][/td][/tr][/table][/b]