by Ann » Sun May 20, 2018 5:38 am
Today's APOD looks great in many ways. Fantastic many-colored swirls and storms of gas rage among torrents of reddish-yellow stars. The sheer power of this cosmic ferocity and fireworks is awe-inspiring!
The source of all this frenzy and fury is a small whitish-looking knot of stars at top center in today's APOD, where it is surrounded by a swarm of tiny pinkish-orange stars. The cluster is, of course, R136.
The link to more information on this cluster provided by the caption takes us to a picture where the cluster looks white to golden-orange. In order to look so orange, there sure must be a lot of red giants in R136!
The magnificent cluster R136.
Photo: NASA, ESA, & F. Paresce, R. O'Connell, & the HST WFC3 S.O.C.
Or not! Take a look at the picture at left of R136. It's nice and blue, isn't it?
But wait - isn't that another false-colored picture? Maybe there are bright stars of all colors in R136? Maybe the blue appearance of the stars in the NASA/ESA/Paresce/O'Connell picture is just caused by filters and processing that make all the bright stars in R136 look blue? Is that it?
No,it sure isn't! This is what Wikipedia says about R136:
Wikipedia wrote:
R136 is thought to be less than 2 million years old.[8][9] None of the member stars is significantly evolved and none is thought to have exploded as supernova. The brightest stars are WNh, O supergiants, and OIf/WN slash stars, all extremely massive fully convective stars. There are
no red supergiants, blue hypergiants, or luminous blue variables within the cluster.
Red supergiant in the outskirts of R136.
Photo: NASA, ESA, & F. Paresce, R. O'Connell, & the HST WFC3 S.O.C.
Actually, there is
one red supergiant in (or just outside) the "outer halo" of R136. Here it is:
R136 and red giant star.
Photo: P Crowther (University of Sheffield)/NASA/ESA/REUTERS
So where is the red giant in relation to R136, then? Well, in the picture at left the star and its position compared with R136 is very obvious, and it looks brighter than it usually does, too.
Ann
Today's APOD looks great in many ways. Fantastic many-colored swirls and storms of gas rage among torrents of reddish-yellow stars. The sheer power of this cosmic ferocity and fireworks is awe-inspiring!
The source of all this frenzy and fury is a small whitish-looking knot of stars at top center in today's APOD, where it is surrounded by a swarm of tiny pinkish-orange stars. The cluster is, of course, R136. [url=https://apod.nasa.gov/apod/ap070506.html]The link to more information on this cluster[/url] provided by the caption takes us to a picture where the cluster looks white to golden-orange. In order to look so orange, there sure must be a lot of red giants in R136!
[float=left][img2]http://scienceblogs.com/startswithabang/files/2013/12/thecore.jpg[/img2][c][size=85]The magnificent cluster R136.
Photo: NASA, ESA, & F. Paresce, R. O'Connell, & the HST WFC3 S.O.C.[/size][/c][/float]
Or not! Take a look at the picture at left of R136. It's nice and blue, isn't it?
But wait - isn't that another false-colored picture? Maybe there are bright stars of all colors in R136? Maybe the blue appearance of the stars in the NASA/ESA/Paresce/O'Connell picture is just caused by filters and processing that make all the bright stars in R136 look blue? Is that it?
No,it sure isn't! This is what Wikipedia says about R136:
[quote][url=https://en.wikipedia.org/wiki/R136#Properties]Wikipedia[/url] wrote:
R136 is thought to be less than 2 million years old.[8][9] None of the member stars is significantly evolved and none is thought to have exploded as supernova. The brightest stars are WNh, O supergiants, and OIf/WN slash stars, all extremely massive fully convective stars. There are [b][size=110][color=#FF0000]no red supergiants[/color][/size][/b], blue hypergiants, or luminous blue variables within the cluster.[/quote]
[float=right][img2]http://scienceblogs.com/startswithabang/files/2012/07/red-giant.jpg[/img2][c][size=85]Red supergiant in the outskirts of R136.
Photo: NASA, ESA, & F. Paresce, R. O'Connell, & the HST WFC3 S.O.C.[/size][/c][/float]
Actually, there is [b][i][size=120]one[/size][/i][/b] red supergiant in (or just outside) the "outer halo" of R136. Here it is: :arrow:
[float=left][img2]https://images.csmonitor.com/csm/2016/03/970946_1_0317-tarantula-nebula-stars_standard.jpg?alias=standard_600x400[/img2][c][size=85]R136 and red giant star.
Photo: P Crowther (University of Sheffield)/NASA/ESA/REUTERS[/size][/c][/float]
So where is the red giant in relation to R136, then? Well, in the picture at left the star and its position compared with R136 is very obvious, and it looks brighter than it usually does, too.
Ann