Beyond wrote:Is there a name for the round red bubble in the lower right?
I think you mean the red bubble called van den Bergh 70.
In this picture, you can see van den Bergh 70 at upper left.
Sidney van den Bergh cataloged
all
BD and CD stars north of -33 deg which are surrounded by reflection nebulosity visible on both the blue and red prints of the Palomar Sky Survey.
The van den Bergh catalog contains 159 reflection nebulae.
Reflection nebulae, unlike emission nebula, reflect the light of a star rather than emit their own light.
Reflection nebulae are typically blue, but a very few may be another color entirely: the most famous one is the
dusty yellow reflection nebula around Antares.
Reflection nebulae are typically found around young stars, often stars of spectral classes B and A. Sidney van den Bergh has cataloged several reflection nebulae in the NGC 2170 complex itself. There are several stars of spectral class B in and near NGC 2170.
The star inside van den Bergh 70 is of spectral class B1, according to my software. A star of that spectral class
is just hot enough to ionize a (relatively faint) red emission nebula. Dust in the vicinity of the star reflects the blue light of the star.
Let me say, finally, that today's APOD is glorious! That part of Barnard's Loop really does look like some kind of lumbering red space giant with a huge red nose and a small blue eye, contemplating those baby nebulae and baby stars that he has just discovered!
(Will he eat them?)
Ann
[quote="Beyond"]Is there a name for the round red bubble in the lower right?[/quote]
I think you mean the red bubble called van den Bergh 70. [url=http://www.tvdavisastropics.com/astroimages-1_00006c.htm]In this picture[/url], you can see van den Bergh 70 at upper left.
Sidney van den Bergh cataloged
[quote]all [url=http://en.wikipedia.org/wiki/Star_catalogue#BD.2FCD.2FCPD]BD and CD stars[/url] north of -33 deg which are surrounded by reflection nebulosity visible on both the blue and red prints of the Palomar Sky Survey.[/quote]
The van den Bergh catalog contains 159 reflection nebulae.
Reflection nebulae, unlike emission nebula, reflect the light of a star rather than emit their own light. [url=http://4.bp.blogspot.com/_srdqqh6m-7o/TNqHgYX-FII/AAAAAAAAArg/OhIoZ8VERIY/s1600/pleiades_andreo.jpg]Reflection nebulae are typically blue[/url], but a very few may be another color entirely: the most famous one is the [url=http://www.dl-digital.com/images/Astronomy/Mess-Clusters/Antares1-medCombine-cp3.jpg]dusty yellow reflection nebula around Antares[/url].
Reflection nebulae are typically found around young stars, often stars of spectral classes B and A. Sidney van den Bergh has cataloged several reflection nebulae in the NGC 2170 complex itself. There are several stars of spectral class B in and near NGC 2170.
The star inside van den Bergh 70 is of spectral class B1, according to my software. A star of that spectral class [url=http://www.uni.edu/morgans/astro/course/Notes/section2/spectraltemps.html]is just hot enough[/url] to ionize a (relatively faint) red emission nebula. Dust in the vicinity of the star reflects the blue light of the star.
Let me say, finally, that today's APOD is glorious! That part of Barnard's Loop really does look like some kind of lumbering red space giant with a huge red nose and a small blue eye, contemplating those baby nebulae and baby stars that he has just discovered! :D (Will he eat them?) :shock:
Ann