Filter -for- red
From: idont1@hotmail.com (Idon't)
Subject: Filter "for" red??
Date: 11 Apr 2002 17:25:06 -0700
Xref: sn-us sci.astro:368943

There is something I would like to understand more fully. Nancy Leider
advised using a certain filter when attempting to image PX. This
filter was said to be *FOR* red. Help me out here. A filter "for" red
would simply cut out all other portions of the light spectrum, yes? If
PX(or any object) was mainly putting out light in this "red" part of
the spectrum, what purpose would be served by filtering out light
which was not present anyway? How could filtering "for" red serve any
usefull purpose in attempting to image such an object?

Thanks, I
Subject: Re: Filter "for" red??
From: Lawrence Quimby <lsquimby@mac.com>
Date: Fri, 12 Apr 2002 03:34:28 GMT
Xref: sn-us sci.astro:368955

Not that I believe Nancy means this...
Not that I believe we'll ever see PX in 2003...

Filtering for red could suppress the light from other objects, making a
red one stand out better. One trick I have used with filters, is to
hold them in front of the eyepiece and move them back and forth so that
I first view the field without a filter, then with a filter, and then
without, etc.

Suppose I am searching for a small planetary nebula. After locating the
proper field, if I don't see the nebula, I would select a nebula
filter. Normal stars will fade out with a filter in place, but a nebula
may not. The differences allow me to locate nebula more quickly and
easily.

--
LS Quimby
From: Bob Officer <bobofficers@earthlink.net>
Subject: Re: Filter "for" red??
Date: Fri, 12 Apr 2002 10:43:59 -0700

On 11 Apr 2002 17:25:06 -0700, in sci.astro, idont1@hotmail.com

(Idon't) wrote:

>There is something I would like to understand more fully. Nancy Leider
>advised using a certain filter when attempting to image PX. This
>filter was said to be *FOR* red. Help me out here. A filter "for" red
>would simply cut out all other portions of the light spectrum, yes? If
>PX(or any object) was mainly putting out light in this "red" part of
>the spectrum, what purpose would be served by filtering out light
>which was not present anyway? How could filtering "for" red serve any
>usefull purpose in attempting to image such an object?
>
>Thanks, I

I suspect it would decrease the brightness blue and yellow objects
which tend to dominate most views from a telescope...


--
Ujosdi
From: John & Tarja Shakespeare
Subject: Re: Filter "for" red??
Date: Fri, 12 Apr 2002 21:19:38 +0300

Hi Idon't

Idon't wrote:

> There is something I would like to understand more fully. Nancy Leider
> advised using a certain filter when attempting to image PX. This
> filter was said to be *FOR* red. Help me out here. A filter "for" red
> would simply cut out all other portions of the light spectrum, yes? If
> PX(or any object) was mainly putting out light in this "red" part of
> the spectrum, what purpose would be served by filtering out light
> which was not present anyway? How could filtering "for" red serve any
> usefull purpose in attempting to image such an object?

It would probably not help at all.

Stars have more-or-less continuous spectra, but their photosphere
temperatures differ, and hence their spectra peak in different wavelength
ranges. As a result, they appear to have different colours, which helps us
to distinguish them. Using a low to moderate density red filter would make
all stars appear reddish, and probably very red. Those stars which are
normally seen as blueish would be reduced in apparent brightness more than
those which are yellowish, which in turn would be reduced in brightness
more than those which are reddish.

So, using a red filter:
- blueish stars would appear red, but a lot less bright
- yellowish stars would appear red, but somewhat less bright
- reddish stars would appear red, but slightly less bright

In other words, using a red filter merely rmoves one means of
distinguishing between objects: they all appear red. It does not help so
much in eliminating blueish stars either, since these tend to be brighter
than the yellowish ones, which tend to be brighter than most reddish ones
(there are exceptions, such as Betelgeuse, of course, which are both
reddish and bright). All stars would appear to be red and dimmer, and the
number of objects which would look like each other would increase.

Best Regards,
John.


--
Remove the DÖTS from shäkëspëärë to get a valid email address.
From: idont1@hotmail.com (Idon't)
Subject: Re: Filter "for" red??
Date: 12 Apr 2002 17:20:14 -0700
Xref: sn-us sci.astro:369079

John & Tarja Shakespeare <"=?iso-8859-1?Q?sh=E4k=EBsp=EB=E4r=EBD=D6TS?=" @mbnet.fi> wrote in message news:<3CB72539.A1DB2D2B@mbnet.fi>...
> Hi Idon't
>
> Idon't wrote:
>
> > There is something I would like to understand more fully. Nancy Leider
> > advised using a certain filter when attempting to image PX. This
> > filter was said to be *FOR* red. Help me out here. A filter "for" red
> > would simply cut out all other portions of the light spectrum, yes? If
> > PX(or any object) was mainly putting out light in this "red" part of
> > the spectrum, what purpose would be served by filtering out light
> > which was not present anyway? How could filtering "for" red serve any
> > usefull purpose in attempting to image such an object?
>
> It would probably not help at all.
>
> Stars have more-or-less continuous spectra, but their photosphere
> temperatures differ, and hence their spectra peak in different wavelength
> ranges. As a result, they appear to have different colours, which helps us
> to distinguish them. Using a low to moderate density red filter would make
> all stars appear reddish, and probably very red. Those stars which are
> normally seen as blueish would be reduced in apparent brightness more than
> those which are yellowish, which in turn would be reduced in brightness
> more than those which are reddish.
>
> So, using a red filter:
> - blueish stars would appear red, but a lot less bright
> - yellowish stars would appear red, but somewhat less bright
> - reddish stars would appear red, but slightly less bright
>
> In other words, using a red filter merely rmoves one means of
> distinguishing between objects: they all appear red. It does not help so
> much in eliminating blueish stars either, since these tend to be brighter
> than the yellowish ones, which tend to be brighter than most reddish ones
> (there are exceptions, such as Betelgeuse, of course, which are both
> reddish and bright). All stars would appear to be red and dimmer, and the
> number of objects which would look like each other would increase.
>
> Best Regards,
> John.

Thanks, that's more or less what I thought. From what you say at the
end, this red filtering might only serve to *increase* the confusion
about which object was which, and whether any object might be PX. Why
does this not surprise me?

I
From: Thomas McDonald <tsmac@wwt.net>
Subject: Re: Filter "for" red??
Date: Sat, 13 Apr 2002 00:33:21 -0500
Xref: sn-us sci.astro:369108

Idon't wrote:

>John & Tarja Shakespeare <"=?iso-8859-1?Q?sh=E4k=EBsp=EB=E4r=EBD=D6TS?=" @mbnet.fi> wrote in message news:<3CB72539.A1DB2D2B@mbnet.fi>...
>
>>Hi Idon't
>>
>>Idon't wrote:
>>
>>>There is something I would like to understand more fully. Nancy Leider
>>>advised using a certain filter when attempting to image PX. This
>>>filter was said to be *FOR* red. Help me out here. A filter "for" red
>>>would simply cut out all other portions of the light spectrum, yes? If
>>>PX(or any object) was mainly putting out light in this "red" part of
>>>the spectrum, what purpose would be served by filtering out light
>>>which was not present anyway? How could filtering "for" red serve any
>>>usefull purpose in attempting to image such an object?
>>>
>>It would probably not help at all.
>>
>>Stars have more-or-less continuous spectra, but their photosphere
>>temperatures differ, and hence their spectra peak in different wavelength
>>ranges. As a result, they appear to have different colours, which helps us
>>to distinguish them. Using a low to moderate density red filter would make
>>all stars appear reddish, and probably very red. Those stars which are
>>normally seen as blueish would be reduced in apparent brightness more than
>>those which are yellowish, which in turn would be reduced in brightness
>>more than those which are reddish.
>>
>>So, using a red filter:
>>- blueish stars would appear red, but a lot less bright
>>- yellowish stars would appear red, but somewhat less bright
>>- reddish stars would appear red, but slightly less bright
>>
>>In other words, using a red filter merely rmoves one means of
>>distinguishing between objects: they all appear red. It does not help so
>>much in eliminating blueish stars either, since these tend to be brighter
>>than the yellowish ones, which tend to be brighter than most reddish ones
>>(there are exceptions, such as Betelgeuse, of course, which are both
>>reddish and bright). All stars would appear to be red and dimmer, and the
>>number of objects which would look like each other would increase.
>>
>>Best Regards,
>>John.
>>
>
>Thanks, that's more or less what I thought. From what you say at the
>end, this red filtering might only serve to *increase* the confusion
>about which object was which, and whether any object might be PX. Why
>does this not surprise me?
>
>I
>
Dear I, et al.,

Yup, Nancy is at the point where she needs all the confusion that
she can get.

When she proposed the 'filter FOR red' business, the problem she
was trying to solve was that people were looking for 'Planet X' and not
finding it. She tried to deal with this by stating a magnitude for
Planet X (I believe it was mag. 2), but because it was dim and red, an
observer needed to filter "FOR" red, and also look for objects down to
11th magnitude. (She said only observatory grade scopes could work for
this, as, among other bells and whistles, they had 'zoom' knobs. My
otherwise-OK 8" LX 10, unfortunately, was made without this knob, and
therefore couldn't see this mag. 2, mag. 11, dim red thingie.)

Now her problem is that people _have_ seen 'Planet X,' per her. And
she has been led by the Zetas to point out a blob of 20th magnitude (or
dimmer) noise on a couple of CCD images as Planet X. So her problem now
is not that _no one_ can see it; it is that she and some of her folks
have now claimed to have found it, but no one outside the ZT/TT bunch can.

When the magnitude business was working in her favor, she would
discuss magnitude until the cows came home. (About sunset, this time of
year.) She would not only give her garbled and humorous views on
magnitude, but she'd also give magnitude _numbers_.

Now the magnitude business is working against her. She has to
change history for her followers, and claim new weird stuff about
magnitude. She also has to attack people, such as my humble self, who
ask her to do now what she's done consistently up until now: tell us the
current magnitude of Planet X.

Nancy is riding the tiger. TT/ZT is hemorrhaging members. If she
states a magnitude, some will leave her little clutch because they will
see that her claims are either inconsistent, or blatantly wrong. If she
doesn't state a magnitude, some will leave because she, or her Zetas,
will have failed, clearly and without dispute, to keep up the appearance
of using real science.

The only way she can win now is to change the subject, attack people
who ask for clarification, and invent new explanations as to why
magnitude, once so important to her, is now irrelevant. As she does a
cost/benefit analysis on this, she can only decide that her only hope at
this point is the last option. She will have to try to reverse-engineer
some old Zetababble to cover her gaping credibility wound, and she will
have to rely increasingly on Jan and some others of the faithful
shepherds of Zetatalk/TT to keep the troops in line.

Look for big fun in the near future.

Tom McDonald