IC 1805 a bright nebula in Cassiopeia

Big Images from Small Telescopes (2)

IC 1805 a bright nebula in Cassiopeia

IC1805 is unusual in that even the usually mega reliable SkyMap Pro
doesn't really give a good impression of what the nebula will look
like though a telescope. Indeed the first time I imaged IC 1805 I had
to double check that I had not mis-identified the object. IC1805 was
both larger and more complex than I had imagined.

The image was created by median combining 6 x 300 second images taken
with a Takahashi Sky 90 with SBIG ST-10MXE and a Hydrogen Alpha
filter.

http://www.martin-nicholson.info/ic1805/ic1805.htm

Martin Nicholson, Daventry, England.

My website is at http://www.martin-nicholson.info/1/1a.htm
My informal Astronomical Blog is at http://ukastronomy.livejournal.com/

ukastronomy wrote:
Big Images from Small Telescopes (2)

IC 1805 a bright nebula in Cassiopeia

IC1805 is unusual in that even the usually mega reliable SkyMap Pro
doesn't really give a good impression of what the nebula will look
like though a telescope. Indeed the first time I imaged IC 1805 I had
to double check that I had not mis-identified the object. IC1805 was
both larger and more complex than I had imagined.

The image was created by median combining 6 x 300 second images taken
with a Takahashi Sky 90 with SBIG ST-10MXE and a Hydrogen Alpha
filter.



Martin,

I don't know of anyone imaging in Ha at only 300s exposures. And even
more so from a real dark location. The evidence of these short exposures
is seen in the noisy background. I would strongly urge you to go at
least 30 minute sub exposures.

Also in your image you have stretched it too far and have "blown out"
some of the brighter detail.

Bill

On 24 Jul, 19:20, "William R. Mattil" wrote:
..

Martin,

I don't know of anyone imaging in Ha at only 300s exposures. And even
more so from a real dark location. The evidence of these short exposures
is seen in the noisy background. I would strongly urge you to go at
least 30 minute sub exposures.

Also in your image you have stretched it too far and have "blown out"
some of the brighter detail.

Bill

OK - I will give it a go and post the results later.

Martin Nicholson
Daventry, UK

On Jul 24, 2:11*pm, ukastronomy
wrote:
On 24 Jul, 19:20, "William R. Mattil" wrote:
.



Martin,

I don't know of anyone imaging in Ha at only 300s exposures. And even
more so from a real dark location. The evidence of these short exposures
is seen in the noisy background. I would strongly urge you to go at
least 30 minute sub exposures.

Also in your image you have stretched it too far and have "blown out"
some of the brighter detail.

Bill

OK - I will give it a go and post the results later.

Martin Nicholson
Daventry, UK

Here is what it looks like with a series of 30 minute exposures
stacked:

http://geogdata.csun.edu/~voltaire/roland/ic1805.html

Closeup: http://geogdata.csun.edu/~voltaire/roland/ic1805fs.html

Rolando

ukastronomy:

http://www.martin-nicholson.info/ic1805/ic1805.htm

Nice. But you have GOT to lose the flashing yellow text because A) it
ruins the appearance of your photo and B) Such a graphic _may_ trigger
seizures in certain persons.

NY Times, December 20, 1997:

"After an incident this week that made thousands of television viewers
ill, Japan's broadcasters agreed today to draw up voluntary guidelines
for programs to help shield children from flash attacks that could
cause seizures or unconsciousness.

The broadcasters are expected to pledge not to use animation techniques
that have been linked to reports of illness among as many as 12,000
people, most of them children. They were affected by watching a
television program featuring popular cartoon figures called Pokemon, or
Pocket Monsters.

More than 700 viewers were hospitalized after they had convulsions,
vomited blood, had seizures or fell unconscious, apparently because of
the flickering TV. No one has died.

Japan's public and commercial broadcasters agreed to set up an
organization to discuss guidelines for television programs..."

The culprit was the rhythmic flashing of bright colors on the TV screen.

Why not try a mouseover like M45 on this page
http://www.primordial-light.com/deepsky.html? A look at the source
code will tell you how it is done.

Davoud

--
Don't re-elect the past. Vote for the futu Obama in 2008!

usenet *at* davidillig dawt com

"Davoud" wrote:

http://www.martin-nicholson.info/ic1805/ic1805.htm

Nice. But you have GOT to lose the flashing yellow text because A) it
ruins the appearance of your photo and B) Such a graphic _may_ trigger
seizures in certain persons.

Definitely agree with A, but B is very unlikely (minimum flash alternation to
trigger seizures is 3 per second -- quite a bit faster than Martin's text, and
covers a very small area. The Pokemon issue was caused by 12 flash
alternations per second, using alternating red/blue colors over a large
area -- the worst combination).