ASTRO: vdB 148

In his catalog van den Berg lists the surface brightness as very bright,
bright, moderate, faint and very faint. #148 is listed as faint. It is
listed as type II which means the illuminating star is outside the
nebula. His color scale ranges from very blue to blue to moderately
blue, to intermediate to moderately red then red and finally very red.
vdB 148 rates the blue designation. Next he rates the absorption around
the nebula based on star density. That ranges from strong to moderate
to weak to absent. He rates vdB 148 as moderate. In Tom Davis' images
there's an obvious color change surrounding vdB 148 in his image that
would indicate absorption. It clearly shows what van den Berg
considered moderate absorption I did see a faint reddening of my
background I was going to balance out until I looked at Tom's image. I
left it in. It's so weak I doubt you'll notice it however. Tom's image
is on his website at:
http://tvdavisastropics.com/astroimages-1_000102.htm . I recommend you
take a look as it shows the setting for this nebula. His is oriented
east at the top while mine has north at the top.

The PDF of the van den Berg paper announcing his list of 158 is at
http://cdsbib.u-strasbg.fr/cgi-bin/c...J.....71..990V . Click
on the link to ADS services then the link to the PDF file.

14" LX200R @ f/10, L=4x10' RGB=2x10', STL-11000XM, Paramount ME

Rick
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I missed copying the first few lines. Here's the text again.
Rick
_____________

VdB 148 is a reflection nebula around the 8.5 magnitude F2 star HD
239856 which The Sky puts at 338,139,600au or a bit less than 5400
light-years from us. It is located in southern Cepheus.

In his catalog van den Berg lists the surface brightness as very bright,
bright, moderate, faint and very faint. #148 is listed as faint. It is
listed as type II which means the illuminating star is outside the
nebula. His color scale ranges from very blue to blue to moderately
blue, to intermediate to moderately red then red and finally very red.
vdB 148 rates the blue designation. Next he rates the absorption around
the nebula based on star density. That ranges from strong to moderate
to weak to absent. He rates vdB 148 as moderate. In Tom Davis' images
there's an obvious color change surrounding vdB 148 in his image that
would indicate absorption. It clearly shows what van den Berg
considered moderate absorption I did see a faint reddening of my
background I was going to balance out until I looked at Tom's image. I
left it in. It's so weak I doubt you'll notice it however. Tom's image
is on his website at:
http://tvdavisastropics.com/astroimages-1_000102.htm . I recommend you
take a look as it shows the setting for this nebula. His is oriented
east at the top while mine has north at the top.

The PDF of the van den Berg paper announcing his list of 158 is at
http://cdsbib.u-strasbg.fr/cgi-bin/c...J.....71..990V . Click
on the link to ADS services then the link to the PDF file.

14" LX200R @ f/10, L=4x10' RGB=2x10', STL-11000XM, Paramount ME

Rick
--
Prefix is correct. Domain is arvig dot net


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Prefix is correct. Domain is arvig dot net

Beautiful image Rick. This seems to be in the "very faint" category for me.

Stefan

"Rick Johnson" schrieb im Newsbeitrag
...

In his catalog van den Berg lists the surface brightness as very bright,
bright, moderate, faint and very faint. #148 is listed as faint. It is
listed as type II which means the illuminating star is outside the
nebula. His color scale ranges from very blue to blue to moderately
blue, to intermediate to moderately red then red and finally very red.
vdB 148 rates the blue designation. Next he rates the absorption around
the nebula based on star density. That ranges from strong to moderate
to weak to absent. He rates vdB 148 as moderate. In Tom Davis' images
there's an obvious color change surrounding vdB 148 in his image that
would indicate absorption. It clearly shows what van den Berg
considered moderate absorption I did see a faint reddening of my
background I was going to balance out until I looked at Tom's image. I
left it in. It's so weak I doubt you'll notice it however. Tom's image
is on his website at:
http://tvdavisastropics.com/astroimages-1_000102.htm . I recommend you
take a look as it shows the setting for this nebula. His is oriented
east at the top while mine has north at the top.

The PDF of the van den Berg paper announcing his list of 158 is at
http://cdsbib.u-strasbg.fr/cgi-bin/c...J.....71..990V . Click
on the link to ADS services then the link to the PDF file.

14" LX200R @ f/10, L=4x10' RGB=2x10', STL-11000XM, Paramount ME

Rick
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Prefix is correct. Domain is arvig dot net

Yes, you need very dark skies for this one or one heck of a lot of time.
This wasn't the best of nights but limiting magnitude was below 6 but
not the 6.75 of a good night. That's for my old eyes. Younger eyes
have reached 7.25 on really good nights but mine now stop at 6.75 even
after cataract surgery. Only went to 4.5 before surgery. Nice to see
the stars again!

Rick

On 4/24/2013 4:16 PM, Stefan Lilge wrote:
Beautiful image Rick. This seems to be in the "very faint" category for me.

Stefan

"Rick Johnson" schrieb im Newsbeitrag
...

In his catalog van den Berg lists the surface brightness as very bright,
bright, moderate, faint and very faint. #148 is listed as faint. It is
listed as type II which means the illuminating star is outside the
nebula. His color scale ranges from very blue to blue to moderately
blue, to intermediate to moderately red then red and finally very red.
vdB 148 rates the blue designation. Next he rates the absorption around
the nebula based on star density. That ranges from strong to moderate
to weak to absent. He rates vdB 148 as moderate. In Tom Davis' images
there's an obvious color change surrounding vdB 148 in his image that
would indicate absorption. It clearly shows what van den Berg
considered moderate absorption I did see a faint reddening of my
background I was going to balance out until I looked at Tom's image. I
left it in. It's so weak I doubt you'll notice it however. Tom's image
is on his website at:
http://tvdavisastropics.com/astroimages-1_000102.htm . I recommend you
take a look as it shows the setting for this nebula. His is oriented
east at the top while mine has north at the top.

The PDF of the van den Berg paper announcing his list of 158 is at
http://cdsbib.u-strasbg.fr/cgi-bin/c...J.....71..990V . Click
on the link to ADS services then the link to the PDF file.

14" LX200R @ f/10, L=4x10' RGB=2x10', STL-11000XM, Paramount ME

Rick


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Prefix is correct. Domain is arvig dot net