ASTRO: Cass A at 22 hours: time to quit or only 1/4 finished?

maybe 100 hours is overly ambitious :-)

http://www.narrowbandimaging.com/3c4...2hao3_page.htm

i evened out the exposure time: 7.5 hours each in Ha and [SII] and 7 hours
in [OIII]

That came quite far... interesting to see how the Ha is in strong little
knots...

--
Regards, Doug W.
www.photonsfate.com
"Richard Crisp" wrote in message
. ..
maybe 100 hours is overly ambitious :-)

http://www.narrowbandimaging.com/3c4...2hao3_page.htm

i evened out the exposure time: 7.5 hours each in Ha and [SII] and 7 hours
in [OIII]

Richard,

I'd also think that there is little room for improvement here. You caught
some Halpha stuff a bit left of the main "ring" that didn't catch my eye in
other pictures I saw of this object.

Stefan

"Richard Crisp" schrieb im Newsbeitrag
. ..
maybe 100 hours is overly ambitious :-)

http://www.narrowbandimaging.com/3c4...2hao3_page.htm

i evened out the exposure time: 7.5 hours each in Ha and [SII] and 7 hours
in [OIII]

"Stefan Lilge" wrote in message
...
Richard,

I'd also think that there is little room for improvement here. You caught
some Halpha stuff a bit left of the main "ring" that didn't catch my eye
in other pictures I saw of this object.

Realistically when I think about the image as it stands and what happens
with additional exposure I conclude:

1) 4x the exposure will only increase the S/N 2x (23hours - 92 hours)
2) the S/N ratio improvement will help with the noisy background and
possibly make the halpha blob to the left of, and outside the main ring,
slightly more prominent.
3) I may bring out a bit more Ha in the middle part too.

All in all it may be practical to invest another night in the Halpha, but
probably not much more than that.

That would take it from 7.5 hours to maybe 12.5 hours of halpha

all in all I can't see investing 92 to 100 hours in it though: the seeing is
limiting me too much





Stefan

"Richard Crisp" schrieb im Newsbeitrag
. ..
maybe 100 hours is overly ambitious :-)

http://www.narrowbandimaging.com/3c4...2hao3_page.htm

i evened out the exposure time: 7.5 hours each in Ha and [SII] and 7
hours in [OIII]

"Getting better all the time...!" Although, I understand your concerns
about devoting 100 hours. It is a telling stellar remnant.

Richard Crisp wrote:
maybe 100 hours is overly ambitious :-)

http://www.narrowbandimaging.com/3c4...2hao3_page.htm

i evened out the exposure time: 7.5 hours each in Ha and [SII] and 7 hours
in [OIII]


Here's an interesting website showing how it looks at various wavelengths.

http://webusers.astro.umn.edu/~tdela...laborator.html

The Hubble image in SIII, SII+OII, OIII and other frequencies not
colorized is at:
http://webusers.astro.umn.edu/~tdela...e/CasA_clr.gif

Rick

--
Correct domain name is arvig and it is net not com. Prefix is correct.
Third character is a zero rather than a capital "Oh".

"Rick Johnson" wrote in message
...


Richard Crisp wrote:
maybe 100 hours is overly ambitious :-)

http://www.narrowbandimaging.com/3c4...2hao3_page.htm

i evened out the exposure time: 7.5 hours each in Ha and [SII] and 7
hours in [OIII]


Here's an interesting website showing how it looks at various wavelengths.

http://webusers.astro.umn.edu/~tdela...laborator.html

The Hubble image in SIII, SII+OII, OIII and other frequencies not
colorized is at:
http://webusers.astro.umn.edu/~tdela...e/CasA_clr.gif

yeah: they got a lot of interesting detail that the lousy seeing robs from
my image :-(

Richard Crisp wrote:
"Rick Johnson" wrote in message
...


Richard Crisp wrote:

maybe 100 hours is overly ambitious :-)

http://www.narrowbandimaging.com/3c4...2hao3_page.htm

i evened out the exposure time: 7.5 hours each in Ha and [SII] and 7
hours in [OIII]



Here's an interesting website showing how it looks at various wavelengths.

http://webusers.astro.umn.edu/~tdela...laborator.html

The Hubble image in SIII, SII+OII, OIII and other frequencies not
colorized is at:
http://webusers.astro.umn.edu/~tdela...e/CasA_clr.gif


yeah: they got a lot of interesting detail that the lousy seeing robs from
my image :-(

You could always get a taller pier -- much taller

Rick


--
Correct domain name is arvig and it is net not com. Prefix is correct.
Third character is a zero rather than a capital "Oh".

"Rick Johnson" wrote in message
...


Richard Crisp wrote:
"Rick Johnson" wrote in message
...


Richard Crisp wrote:

maybe 100 hours is overly ambitious :-)

http://www.narrowbandimaging.com/3c4...2hao3_page.htm

i evened out the exposure time: 7.5 hours each in Ha and [SII] and 7
hours in [OIII]



Here's an interesting website showing how it looks at various
wavelengths.

http://webusers.astro.umn.edu/~tdela...laborator.html

The Hubble image in SIII, SII+OII, OIII and other frequencies not
colorized is at:
http://webusers.astro.umn.edu/~tdela...e/CasA_clr.gif


yeah: they got a lot of interesting detail that the lousy seeing robs
from my image :-(

You could always get a taller pier -- much taller


needs to be wide too: flexure...

this is getting interesting -

Richard Crisp wrote:

maybe 100 hours is overly ambitious :-)

http://www.narrowbandimaging.com/3c4...2hao3_page.htm

i evened out the exposure time: 7.5 hours each in Ha and [SII] and 7 hours
in [OIII]

[Image]