Starship Asterisk*

[quote=Roy post_id=340996 time=1724875106]
Quasar, IIRC, stands for quasi-stellar object, something very bright but whose light was anomalously red shifted. They were thought to be at the luminous limits of distance we could see at the time. Now we have a star which is a microquasar? So is M87 then a miniquasar in its core? The term seems to be applicable to whatever the person wants to talk about.
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A quasar is a very energetic object resulting from an accretion disk around a supermassive black hole. A microquasar depends on very similar physics, but is the product of an accretion disk around a stellar mass black hole. Two completely separate populations (as there is no overlap between stellar mass and supermassive black holes).

Quasar, IIRC, stands for quasi-stellar object, something very bright but whose light was anomalously red shifted. They were thought to be at the luminous limits of distance we could see at the time. Now we have a star which is a microquasar? So is M87 then a miniquasar in its core? The term seems to be applicable to whatever the person wants to talk about.

Exciting APOD and contributions by Ann and AVAO!
So, a blue supergiant star feeds a microquasar - how will this all end? The star goes supernova leaving behind two black holes eventually merging? The microquasar swallows the whole star? In any case, illustrations are just illustrations but here is the one from the Chandra site for Cygnus X-1, what a spectacular vision of intense energies!
[attachment=0]cygx1.jpg[/attachment]

[quote=AVAO post_id=340990 time=1724820040 user_id=144694]
[quote="APOD Robot" post_id=340989 time=1724817921 user_id=128559]
[url=https://apod.nasa.gov/apod/ap240828.html] [img]https://apod.nasa.gov/apod/calendar/S_240828.jpg[/img] [size=150]Tulip Nebula and Black Hole Cygnus X-1[/size][/url]

[...] [b]Blasted by powerful jets from a [url=https://exoplanets.nasa.gov/resources/2259/devoured-by-gravity-poster/?galaxy_horror]lurking black hole[/url][/b], its fainter bluish curved [url=https://en.wikipedia.org/wiki/Shock_wave]shock front[/url] is only faintly visible [url=https://apod.nasa.gov/apod/ap090608.html]beyond[/url] the cosmic Tulip's petals, near the right side of the frame.


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[imghover="https://live.staticflickr.com/65535/53951761137_cfb09951e8_b.jpg"]https://live.staticflickr.com/65535/53951760477_121456cc06_b.jpg[/imghover]

[size=65]The cross marks the location of the black hole Cygnus X-1 in this radio image. The bright region to the left (east) of the black hole is a dense cloud of gas existing in the space between the stars, the interstellar medium. (Image credit: Gallo et al., Westerbork radio telescope) [url]https://www.space.com/1441-black-hole-forges-invisible-bubble.html[/url] Background: NASA/ESA & more (DSS2color)[/size]
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Wonderful image as always, Jac! :D

Your image strongly suggests that the Tulip Nebula and Cygnus X-1 are close enough to be connected. I checked the Gaia parallaxes for HD 227018 (the ionizing star of the Tulip Nebula) and HD 226868 (the star orbiting the black hole of Cygnus X-1), and they are indeed very similar. Their parallaxes suggest that their distances are 7,200-7,300 light-years.


[float=left][attachment=0]HD 226868 and Tulip Nebula Peter Kohlmann.png[/attachment][c][size=85][color=#0040FF]HD 227018, ionizing star of the Tulip Nebula, and HD 226868,
in orbit of the black hole of Cygnus X-1. Credit: Peter Kohlmann[/color][/size][/c][/float]
[clear][/clear]


We may note that the yellow-looking HD 226868 is really a highly reddened blue supergiant star of spectral class B0. Another interesting aspect is the fact that the jet from Cygnus X-1 (and ensuing lobe and bow shock) appears to be one-sided. The blue OIII arc of Cygnus X-1 is located to the northwest (upper right) of the stellar/black hole system itself.

I am reminded of the mostly one-sided jet from the enormous black hole of giant elliptical galaxy M87.


[float=right][img3="A closeup of the jet. Credit: NASA and the Hubble Heritage Team (STScI/AURA)"]https://science.nasa.gov/wp-content/uploads/2023/04/m87-jet-jpg.webp?w=1536&format=webp[/img3][/float][img3="A mostly one-sided jet from the black hole of M87. Credit: NASA, ESA and the Hubble Heritage Team (STScI/AURA); Acknowledgment: P. Cote (Herzberg Institute of Astrophysics) and E. Baltz (Stanford University)"]https://science.nasa.gov/wp-content/uploads/2023/04/m87-full_jpg-jpg.webp?w=1536&format=webp[/img3]
[clear][/clear]


We can't see the jet of Cygnus X-1, but it must clearly be there.


[img3="Artist's impression of the jet and bow show of Cygnus X-1."]https://jila.colorado.edu/~ajsh/courses/astr2030_19/xraybin/cyg.png[/img3]


Ann

[quote="APOD Robot" post_id=340989 time=1724817921 user_id=128559]
[url=https://apod.nasa.gov/apod/ap240828.html] [img]https://apod.nasa.gov/apod/calendar/S_240828.jpg[/img] [size=150]Tulip Nebula and Black Hole Cygnus X-1[/size][/url]

[...] [b]Blasted by powerful jets from a [url=https://exoplanets.nasa.gov/resources/2259/devoured-by-gravity-poster/?galaxy_horror]lurking black hole[/url][/b], its fainter bluish curved [url=https://en.wikipedia.org/wiki/Shock_wave]shock front[/url] is only faintly visible [url=https://apod.nasa.gov/apod/ap090608.html]beyond[/url] the cosmic Tulip's petals, near the right side of the frame.


[table][tr][td=left][url=https://asterisk.apod.com/discuss_apod.php?date=240827][b]<< Previous APOD[/b][/url][/td] [td=center][url=https://asterisk.apod.com/view_retro.php?date=0828][b]This Day in APOD[/b][/url][/td] [td=right][url=https://asterisk.apod.com/discuss_apod.php?date=240829][b]Next APOD >>[/b][/url][/td][/tr][/table]
[/quote]

[imghover="https://live.staticflickr.com/65535/53951761137_cfb09951e8_b.jpg"]https://live.staticflickr.com/65535/53951760477_121456cc06_b.jpg[/imghover]

[size=65]The cross marks the location of the black hole Cygnus X-1 in this radio image. The bright region to the left (east) of the black hole is a dense cloud of gas existing in the space between the stars, the interstellar medium. (Image credit: Gallo et al., Westerbork radio telescope) [url]https://www.space.com/1441-black-hole-forges-invisible-bubble.html[/url] Background: NASA/ESA & more (DSS2color)[/size]

[url=https://apod.nasa.gov/apod/ap240828.html] [img]https://apod.nasa.gov/apod/calendar/S_240828.jpg[/img] [size=150]Tulip Nebula and Black Hole Cygnus X-1[/size][/url]

[b] Explanation: [/b] When can you see a black hole, a tulip, and a swan all at once? At night -- if the timing is right, and if your telescope is pointed in the [url=https://skywiseunlimited.com/wp-content/uploads/2015/02/scoper_05.jpg]right direction[/url]. The complex and beautiful [url=https://en.wikipedia.org/wiki/Sh_2-101]Tulip Nebula[/url] blossoms about 8,000 [url=https://spaceplace.nasa.gov/light-year/]light-years[/url] away toward the [url=https://en.wikipedia.org/wiki/Cygnus_(constellation)]constellation of Cygnus[/url] the Swan. [url=https://science.nasa.gov/ems/10_ultravioletwaves/]Ultraviolet radiation[/url] from young energetic stars at the edge of the Cygnus [url=https://en.wikipedia.org/wiki/Stellar_kinematics#OB_associations]OB3 association[/url], including [url=https://apod.nasa.gov/apod/ap070726.html]O star[/url] HDE 227018, ionizes the atoms and powers the emission from the Tulip Nebula. [url=https://en.wikipedia.org/wiki/Stewart_Sharpless]Stewart Sharpless[/url] cataloged this nearly 70 light-years across reddish glowing cloud of interstellar gas and dust in [url=https://ui.adsabs.harvard.edu/abs/1959ApJS....4..257S/abstract]1959[/url], as [url=http://galaxymap.org/cat/list/sharpless/101]Sh2-101[/url]. Also in the [url=https://www.astrobin.com/3y9228/]featured field[/url] of view is the black hole [url=http://chandra.harvard.edu/photo/2011/cygx1/]Cygnus X-1[/url], which to be a [url=https://en.wikipedia.org/wiki/Microquasar]microquasar[/url] because it is one of strongest [url=https://science.nasa.gov/ems/11_xrays/]X-ray[/url] sources in planet Earth's sky. Blasted by powerful jets from a [url=https://exoplanets.nasa.gov/resources/2259/devoured-by-gravity-poster/?galaxy_horror]lurking black hole[/url], its fainter bluish curved [url=https://en.wikipedia.org/wiki/Shock_wave]shock front[/url] is only faintly visible [url=https://apod.nasa.gov/apod/ap090608.html]beyond[/url] the cosmic Tulip's petals, near the right side of the frame.


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