Starship Asterisk*

[quote=JohnD post_id=342255 time=1731422478 user_id=100329]
Way outside the Nebula, and happening to be in line of sight between us? 4700lys gives a lot of room for other things!
John
[/quote]

Bok globules like that are associated with star forming regions. I think it's likely part of the nebula. You don't find them floating around in empty space.

Where is the Earth 250000years ago

Probably an "evaporating Gaseous Globule" on the line of sight between us and the nebula. See the October 22nd APOD.

Way outside the Nebula, and happening to be in line of sight between us? 4700lys gives a lot of room for other things!
John

[quote=JohnD post_id=342250 time=1731408300 user_id=100329]
Me too! It looks to cast a shadow of the main star on the structures nearer us. A dust cloud would surely have been long ago blown away?
[/quote]

Looks like just an unusually opaque glob of dust to me. I google but didn't find anything that pointed it out.


[attachment=0]crescent nebula and dark glob.jpg[/attachment]

Me too! It looks to cast a shadow of the main star on the structures nearer us. A dust cloud would surely have been long ago blown away?

I'm wondering what is the hole-like structure just to the left of WR 136.

Alex

[url=https://apod.nasa.gov/apod/ap241112.html] [img]https://apod.nasa.gov/apod/calendar/S_241112.jpg[/img] [size=150]NGC 6888: The Crescent Nebula[/size][/url]

[b] Explanation: [/b] How was the Crescent Nebula created? Looking like an emerging space [url=https://apod.nasa.gov/apod/ap231224.html]cocoon[/url], the Crescent Nebula, visible in the center of the [url=https://astroaro.fr/en/en_ngc-6888/]featured image[/url], was created by the brightest star in its center. A leading progenitor hypothesis has the [url=https://apod.nasa.gov/apod/ap230904.html]Crescent Nebula[/url] beginning to form about 250,000 years ago. At that time, the massive central star had evolved to become a [url=https://apod.nasa.gov/apod/ap200308.html]Wolf-Rayet star[/url] (WR 136), shedding its outer envelope in a strong [url=https://en.wikipedia.org/wiki/Stellar_wind]stellar wind[/url], ejecting the equivalent of our Sun's mass every 10,000 years. This wind impacted surrounding gas left over from a [url=http://hyperphysics.phy-astr.gsu.edu/hbase/astro/redsup.html]previous phase[/url], compacting it into a series of [url=https://apod.nasa.gov/apod/ap240107.html]complex shells[/url], and [url=https://delavanlakesvet.com/wp-content/uploads/sites/195/2022/03/smiling-cat-for-web.jpg]lighting it up[/url]. The [url=https://ui.adsabs.harvard.edu/abs/2000AJ....119.2991M/abstract]Crescent Nebula[/url], also known as NGC 6888, lies about 4,700 [url=https://science.nasa.gov/exoplanets/what-is-a-light-year/]light-year[/url]s away in the [url=https://spaceplace.nasa.gov/constellations/en/]constellation[/url] of [url=https://en.wikipedia.org/wiki/Cygnus_(constellation)]Cygnus[/url]. Star [url=https://astronomy.swin.edu.au/cosmos/w/wolf-rayet+star]WR[/url] 136 will probably undergo a [url=https://youtu.be/wymMn-SmALY]supernova[/url] explosion sometime in the next million years.


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