by Ann » Sun Mar 08, 2020 11:18 am
WR 104 is a worthy subject for an APOD. My own "favorite" Wolf Rayet star is another one, however, the WR component of a triple star system named after a deity in Egyptian mythology, Apep:
Wikipedia wrote:
Apep (/ˈæpɛp/ or /ˈɑːpɛp/; also spelled Apepi or Aapep) or Apophis (/ˈæpəfɪs/; Ancient Greek: Ἄποφις) was the ancient Egyptian deity who embodied chaos (ı͗zft in Egyptian) and was thus the opponent of light and Ma'at (order/truth). He appears in art as a giant serpent.
Apep (the star system) has been named as a possible gamma ray burst progenitor. The fact that we see the "spiral arms" sort of face on suggests that we might be seeing at least one of the Wolf Rayet stars pole on, which again suggests that, if this WR star was to eject a tremendous jet, it might aim it in more or less our direction.
But hey, wait a minute!
I may have been too hasty here, when I suggested that Apep might be the only WR star that is surrounded by a more of less face-on spiral, and which might be capable of firing a gamma ray jet in our direction.
It turns out that the star of today's APOD, WR 104,
might do the same thing!!!
Matt Ransford of Popular Science wrote:
Friends of the Dark Side, your time may soon be at hand. It seems we have a literal death star aiming in our general direction. The culprit is part of a binary star system—two stars which orbit each other—by the name of WR 104. Both are massive and very, very hot. One will eventually explode into a harmless supernova, providing us with a lovely astronomical light show. The other, however, might be deadly.
The evil stellar mass in question is a Wolf Rayet star. When these stars die and the right conditions are met (they must be 30 times more massive than the sun and fast-rotating), they run the risk of collapsing into a spinning black hole, around the axis of which would be powerful jets of high-energy gamma radiation. Turns out, the star meets the criteria. And guess what? Earth is right in its line of fire.
Well, chances are that any "death ray" that WR 104 might release won't be aimed straight at us. To say that space is vast is a mindbogglingly ridiculous understatement, so the chances that any gamma ray burst emitted by WR 104 would miss the Earth seem excellent indeed.
Ann
Edit: Uh, no. The star of today's APOD is WR
124. The star that might spit a gamma ray burst in our faces if WR
104.
Sorry.
![Embarassed :oops:](./images/smilies/icon_redface.gif)
[float=left][img3="The VISIR instrument on ESO’s VLT captured this stunning image of a newly-discovered massive binary star system. Nicknamed Apep after an ancient Egyptian deity, it could be the first gamma-ray burst progenitor to be found in our galaxy. Apep’s stellar winds have created the dust cloud surrounding the system, which consists of a binary star with a fainter companion. With 2 Wolf-Rayet stars orbiting each other in the binary, the serpentine swirls surrounding Apep are formed by the collision of two sets of powerful stellar winds, which create the spectacular dust plumes seen in the image. The reddish pinwheel in this image is data from the VISIR instrument on ESO’s Very Large Telescope (VLT), and shows the spectacular plumes of dust surrounding Apep. The blue sources at the centre of the image are a triple star system — which consists of a binary star system and a companion single star bound together by gravity. Though only two star-like objects are visible in the image, the lower source is in fact an unresolved binary Wolf-Rayet star. The triple star system was captured by the NACO adaptive optics instrument on the VLT. Photo: ESO/Callingham et al."]https://upload.wikimedia.org/wikipedia/commons/thumb/5/5b/The_triple_star_system_2XMM_J160050.7%E2%80%93514245_%28Apep%29.jpg/1024px-The_triple_star_system_2XMM_J160050.7%E2%80%93514245_%28Apep%29.jpg[/img3][/float] [float=right][img3="Ancient Egyptian art depicting Apep being warded off by a deity."]https://upload.wikimedia.org/wikipedia/commons/a/a7/Apep_1.jpg[/img3][/float]
WR 104 is a worthy subject for an APOD. My own "favorite" Wolf Rayet star is another one, however, the WR component of a triple star system named after a deity in Egyptian mythology, Apep:
[quote][url=https://en.wikipedia.org/wiki/Apep]Wikipedia[/url] wrote:
Apep (/ˈæpɛp/ or /ˈɑːpɛp/; also spelled Apepi or Aapep) or Apophis (/ˈæpəfɪs/; Ancient Greek: Ἄποφις) was the ancient Egyptian deity who embodied chaos (ı͗zft in Egyptian) and was thus the opponent of light and Ma'at (order/truth). He appears in art as a giant serpent. [/quote]
Apep (the star system) has been named as a possible gamma ray burst progenitor. The fact that we see the "spiral arms" sort of face on suggests that we might be seeing at least one of the Wolf Rayet stars pole on, which again suggests that, if this WR star was to eject a tremendous jet, it might aim it in more or less our direction.
[b][size=120][color=#0080FF]But hey, wait a minute![/color][/size][/b]
I may have been too hasty here, when I suggested that Apep might be the only WR star that is surrounded by a more of less face-on spiral, and which might be capable of firing a gamma ray jet in our direction. [b][color=#0080FF]It turns out that the star of today's APOD, WR 104[/color][/b], [b][i][size=110][color=#FF0000]might do the same thing!!![/color][/size][/i][/b] :shock:
[quote][url=https://www.popsci.com/military-aviation-space/article/2008-03/real-life-death-star/]Matt Ransford of Popular Science[/url] wrote:
Friends of the Dark Side, your time may soon be at hand. It seems we have a literal death star aiming in our general direction. The culprit is part of a binary star system—two stars which orbit each other—by the name of WR 104. Both are massive and very, very hot. One will eventually explode into a harmless supernova, providing us with a lovely astronomical light show. The other, however, might be deadly.
The evil stellar mass in question is a Wolf Rayet star. When these stars die and the right conditions are met (they must be 30 times more massive than the sun and fast-rotating), they run the risk of collapsing into a spinning black hole, around the axis of which would be powerful jets of high-energy gamma radiation. Turns out, the star meets the criteria. And guess what? Earth is right in its line of fire.[/quote][float=right][img3="WR 104. U.C. Berkeley Space Sciences Laboratory."]https://www.popsci.com/resizer/uom2J_lSdmWUrWQffHdJ1QjoY9k=/533x426/arc-anglerfish-arc2-prod-bonnier.s3.amazonaws.com/public/LLVO2CN32OX2WNTHEHH4CK5JDQ.jpg[/img3][/float]
Well, chances are that any "death ray" that WR 104 might release won't be aimed straight at us. To say that space is vast is a mindbogglingly ridiculous understatement, so the chances that any gamma ray burst emitted by WR 104 would miss the Earth seem excellent indeed.
Ann
Edit: Uh, no. The star of today's APOD is WR [b][color=#0040FF]124[/color][/b]. The star that might spit a gamma ray burst in our faces if WR [b][color=#FF0000]104[/color][/b].
Sorry. :oops: