by Ann » Mon Jun 27, 2022 5:25 am
The APOD looks fantastic, as if the sky was on soft reddish fire.
There are a number of great stars here, too.
Tau CMa is the luminary of beautiful cluster NGC 2362. Another O-type star, 29 CMa, is located close to it.
Delta CMA is a yellow-white supergiant, a huge star whose "surface temperature" is very similar to the temperature of the Sun. If this star was placed at the center of the solar system, it would swallow the Earth.
Eta CMa is a blue supergiant.
Epsilon CMA, Adhara, is the greatest source of ultraviolet light in the nearby universe. Adhara is a bright giant of spectral class B2II, and it is "only" some 400 light-years away, quite comparable to the Pleiades.
Sigma CMa is a bright red giant or a lesser red supergiant, and Pi Puppis is a lesser red supergiant.
NGC 2451 contains a bright red giant, HD 63032.
Zeta Puppis is a brilliant O-type star of spectral type O5Iaf. It radiates some 12,000 solar luminosities at optical wavelengths, but because it is such a hot O-type stars whose blackbody curve peaks far into the ultraviolet part of the spectrum, its total energy production is over 500,000 suns.
Gamma Velorum is an even more remarkable star than Zeta Puppis. It is a quadruple star whose main components are one O-type giant and one Wolf Rayet star. The Wolf Rayet component is going to explode as a Type Ib supernova.
It has been speculated that Zeta Puppis and Gamma Velorum could provide enough ultraviolet light to ionize the Gum Nebula. But today, a supernova remnant is considered an equally likely source of the nebula.
Interestingly, Zeta Puppis is a runaway star. It is also a single star, which is most unusual for very massive stars. It is quite possible that Zeta Puppis once had a companion that exploded as a supernova and sent Zeta Puppis flying.
Ann
[float=left][img3="The Gum Nebula over Snowy Mountains. Image Credit & Copyright: Wang Jin"]https://apod.nasa.gov/apod/image/2206/GumMountain_WangJin_1080.jpg[/img3][/float][float=right][attachment=0]APOD 27 June 2022 Gum Nebula annotated stars.png[/attachment][/float]
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The APOD looks fantastic, as if the sky was on soft reddish fire.
There are a number of great stars here, too.
[img3="Brilliant O-type star Tau Canis Majoris in cluster NGC 2362. O-type star 29 CMa is located close to it. Credit and copyright: Ray Caro."]https://cdn.astrobin.com/solutions/images/22547/2018/d7f9b43a-0068-43f6-a118-096734be9168-1582472186.jpg[/img3]
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Tau CMa is the luminary of beautiful cluster NGC 2362. Another O-type star, 29 CMa, is located close to it.
Delta CMA is a yellow-white supergiant, a huge star whose "surface temperature" is very similar to the temperature of the Sun. If this star was placed at the center of the solar system, it would swallow the Earth.
Eta CMa is a blue supergiant.
Epsilon CMA, Adhara, is the greatest source of ultraviolet light in the nearby universe. Adhara is a bright giant of spectral class B2II, and it is "only" some 400 light-years away, quite comparable to the Pleiades.
Sigma CMa is a bright red giant or a lesser red supergiant, and Pi Puppis is a lesser red supergiant.
[img3="NGC 2451 and its bright red luminary, HD 63032. Image: Donald Pelletier."]https://upload.wikimedia.org/wikipedia/commons/3/3b/NGC_2451_DSS.jpg?20180329072925[/img3]
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NGC 2451 contains a bright red giant, HD 63032.
[url=https://en.wikipedia.org/wiki/Zeta_Puppis]Zeta Puppis[/url] is a brilliant O-type star of spectral type O5Iaf. It radiates some 12,000 solar luminosities at optical wavelengths, but because it is such a hot O-type stars whose blackbody curve peaks far into the ultraviolet part of the spectrum, its total energy production is over 500,000 suns.
[url=https://en.wikipedia.org/wiki/Gamma_Velorum]Gamma Velorum[/url] is an even more remarkable star than Zeta Puppis. It is a quadruple star whose main components are one O-type giant and one Wolf Rayet star. The Wolf Rayet component is going to explode as a Type Ib supernova.
It has been speculated that Zeta Puppis and Gamma Velorum could provide enough ultraviolet light to ionize the Gum Nebula. But today, a supernova remnant is considered an equally likely source of the nebula.
Interestingly, Zeta Puppis is a runaway star. It is also a single star, which is most unusual for very massive stars. It is quite possible that Zeta Puppis once had a companion that exploded as a supernova and sent Zeta Puppis flying.
Ann