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Mifletz
2001-Nov-28, 02:01 AM
How is this possible if even the Hubble cannot yet resolve a stellar disc?!

http://www.rense.com/general17/planetwithatmos.htm

David Simmons
2001-Nov-28, 02:17 AM
On 2001-11-27 21:01, Mifletz wrote:
How is this possible if even the Hubble cannot yet resolve a stellar disc?!



The planet passed between the star and the Hubble. I live on in hopes that you really want to know and aren't just trolling. See this link Planetary Atmosphere (http://www.gsfc.nasa.gov/news-release/releases/2001/h01-232.htm)

Mifletz
2001-Nov-28, 02:50 AM
Has the Hubble or any other telescope taken a proper uncomputer-tampered with undistorted unambiguous normal light photographic image showing clearly an actual arc-resolvable disc (ie not pin point image) of any star apart from our Sun?

Torsten
2001-Nov-28, 02:56 AM
"How is this possible if even the Hubble cannot yet resolve a stellar disc?!"

Check out Protoplanetary discs in Orion (http://www.seds.org/hst/OriProp4.html)

and

Edge-on Protoplanetary disc in Orion Nebula (http://www.seds.org/hst/OriEODsk.html).


"Has the Hubble or any other telescope taken a proper uncomputer-tampered with undistorted unambiguous normal light photographic image showing clearly an actual arc-resolvable disc (ie not pin point image) of any star apart from our Sun?"

Is this good enough?:

http://oposite.stsci.edu/pubinfo/jpeg/Btlgeuse.jpg

Space Telescope Science Institute (http://oposite.stsci.edu/pubinfo/Latest.html)

<font size=-1>[ This Message was edited by: Torsten on 2001-11-27 22:14 ]</font>

Silas
2001-Nov-28, 03:16 AM
On 2001-11-27 21:50, Mifletz wrote:
Has the Hubble or any other telescope taken a proper uncomputer-tampered with undistorted unambiguous normal light photographic image showing clearly an actual arc-resolvable disc (ie not pin point image) of any star apart from our Sun?


Of course not: all such photographs have been "distorted" by the lens through which they were taken.

I actually once met a man who refused to accept any evidence that was not visible to the unaided human eye...

Silas

David Simmons
2001-Nov-28, 04:46 AM
On 2001-11-27 21:50, Mifletz wrote:
Has the Hubble or any other telescope taken a proper uncomputer-tampered with undistorted unambiguous normal light photographic image showing clearly an actual arc-resolvable disc (ie not pin point image) of any star apart from our Sun?


You have a marvelous talent for making people rue ever having responded to your posts.

The great majority of detailed, scientific knowledge of stars, including the sun, has been gained by spectroscopic analysis of the light from the star in question. If you don't know and appreciate that then everyone is just wasting time in answering you.

P.S. My hopes were dashed to the ground with respect to your trolling. See link: Blind Alley (http://www.winternet.com/~mikelr/flame78.html)


<font size=-1>[ This Message was edited by: David Simmons on 2001-11-28 00:08 ]</font>

Simon
2001-Nov-28, 06:38 AM
On 2001-11-27 21:50, Mifletz wrote:
Has the Hubble or any other telescope taken a proper uncomputer-tampered with undistorted unambiguous normal light photographic image showing clearly an actual arc-resolvable disc (ie not pin point image) of any star apart from our Sun?


Well, since all the Hubble information is transmitted to Earth in binary and reassembled in to pictures by computers, not to mention the fact that just about ALL professional astronomy uses CCD detectors hooked, once again, to computers, it's sorta hard to find ANY image that isn't "computer tampered."

GrapesOfWrath
2001-Nov-28, 08:31 AM
On 2001-11-27 21:50, Mifletz wrote:
Has the Hubble or any other telescope taken a proper uncomputer-tampered with undistorted unambiguous normal light photographic image showing clearly an actual arc-resolvable disc (ie not pin point image) of any star apart from our Sun?

Torsten's picture is accompanied by a brief description (http://oposite.stsci.edu/pubinfo/gif/Btlgeuse.txt), which says that what you are asking about first occurred March 3, 1995. And here is an June 5, 199 APOD (http://antwrp.gsfc.nasa.gov/apod/ap990605.html) with an image from the same researchers, that says it is "the first direct picture of the surface of a star other than the Sun". Betelgeuse is only 600 light years away, and a 1000 times the diameter of the sun. However, there seems to be some disagreement. Here is a link to an April 25, 2001 press release of the European Southern Observatory (http://www.hq.eso.org/outreach/press-rel/pr-2001/pr-09-01.html) that says that, other than the sun, "all other stars are so far away that they normally appear as points of light." I guess you have to figure out what "normally" means.
_________________
rocks

<font size=-1>[Fixed APOD link]</font>

<font size=-1>[ This Message was edited by: GrapesOfWrath on 2001-11-28 03:33 ]</font>

ToSeek
2001-Nov-28, 01:37 PM
On 2001-11-27 22:16, Silas wrote:

I actually once met a man who refused to accept any evidence that was not visible to the unaided human eye...



I found a web page once of a group that believes that NASA is researching virtual reality technology for the sole purpose of faking images from Hubble and the Mars orbiters.

DStahl
2001-Nov-28, 07:55 PM
This is quite off-topic, but I loved the catalogue of Flame Warriors at David Simmons' link. Online forums and BBs are fascinating social microcosms--on the BABB everyone seems to be pretty much themselves, but on another forum I visit everyone is quite clearly playing one or more characters. Love it.

2001-Nov-28, 10:17 PM
OIs this good enough?:

http://oposite.stsci.edu/pubinfo/jpeg/Btlgeuse.jpg

Space Telescope Science Institute (http://oposite.stsci.edu/pubinfo/Latest.html)

<font size=-1>[ This Message was edited by: Torsten on 2001-11-27 22:14 ]</font>


Can you put a scale on it in terms of images size? Like mark of 1 microradian, or microdegree, or whatever angle is appropriate.
I am trying to do a parallax free calculation of the distance to Betelgeuse. I plan to use the black body radiation formulas. I need the angular size of Betelegeuse for this calculation. The scale you showed (=one earth orbit) was derived by geometric parallax. I can't use it. I need an angular size.

ToSeek
2001-Nov-28, 10:45 PM
On 2001-11-28 17:17, Rosen1 wrote:

I am trying to do a parallax free calculation of the distance to Betelgeuse. I plan to use the black body radiation formulas. I need the angular size of Betelegeuse for this calculation. The scale you showed (=one earth orbit) was derived by geometric parallax. I can't use it. I need an angular size.



Does this help?:

http://imagine.gsfc.nasa.gov/YBA/HTCas-size/betelgeuse.html

ToSeek
2001-Nov-28, 10:46 PM
I'll save you the trouble. It's roughly 50 milliarcseconds (.05 arcseconds).

2001-Nov-29, 06:26 PM
On 2001-11-28 17:46, ToSeek wrote:
I'll save you the trouble. It's roughly 50 milliarcseconds (.05 arcseconds).


Thanks. Just three minor problems. I can get an estimate on this datum alone, but answering the following would give me a more accurate calculation.


First, is this an angular diameter or an angular radius?

Second, I am doing this calculation to answer a certain party who is very skeptical of parallax. The Website has us calculate the image size knowing the distance. The author obviously got this distance using parallax. I would like to assure him that absolutely no use of geometric parallax was used.

Now I know that the author got the distance from parallax, had his picture with a scale of arcsec, and then recalculated the scale in distance. I have no problem with this. However, to convince or at least embarrass this guy I need a "raw data" estimate of angular diameter.

Third, is this a "true color" photograph of Betelgeuse and from what part of the picture is this measured? I would have to estimate the average temperature of the image, and obviously it varies with distance. I can calculate an approximate temperature just by assummming "Betelgeuse is red hot, but maybe I can use the colors in this photo to get a more accurate estimate.

ToSeek
2001-Nov-29, 07:39 PM
On 2001-11-29 13:26, Rosen1 wrote:


On 2001-11-28 17:46, ToSeek wrote:
I'll save you the trouble. It's roughly 50 milliarcseconds (.05 arcseconds).


Thanks. Just three minor problems. I can get an estimate on this datum alone, but answering the following would give me a more accurate calculation.


First, is this an angular diameter or an angular radius?

Third, is this a "true color" photograph of Betelgeuse and from what part of the picture is this measured? I would have to estimate the average temperature of the image, and obviously it varies with distance. I can calculate an approximate temperature just by assummming "Betelgeuse is red hot, but maybe I can use the colors in this photo to get a more accurate estimate.


Here's the press release:

http://oposite.stsci.edu/pubinfo/gif/Btlgeuse.txt

You should be able to recalculate the apparent size from the statement that it's 20,000 times smaller than the full moon. (The moon is about 0.5 degrees.)

The image is taken in ultraviolet light, so you shouldn't try to calculate the temperature based on the colors in the image.

2001-Dec-01, 12:17 AM
You should be able to recalculate the apparent size from the statement that it's 20,000 times smaller than the full moon. (The moon is about 0.5 degrees.)

That will do it if we are really talking about black body radiation..


The image is taken in ultraviolet light, so you shouldn't try to calculate the temperature based on the colors in the image.

The article doesn't mention the average wavelength of the outer atmosphere. It mentions a "hot spot," but I don't know if this temperature is typical of that spot. It could be that the UV radiation is from synchrotron sources, or line emission, or any of a number of nonblack body sources. If the atmosphere that far away from the core is thin enough, the UV won't follow a black body spectrum. In fact, it could be the tail end of the black body spectrum from a much cooler region.
What would you say that the range of UV wavelengths in Hubbles image apparatus is?

The person that I am debating claims that "plasma physicists all say that astronomers don't know any plasma physicists." This person understands no "plasma physics" himself, and I am not sure that many "plasma physicists" would agree.
Still, I think a black body calculation would be more compelling if there is little "line spectra" or "synchrotron radiation." If the atmosphere is large enough to absorb and reemit its own radiation, the spectrum has to come close to a black body independent of the real "plasma physics."
However, this may be enough information for a rough estimate. Thanks.

2001-Dec-01, 12:32 AM
On 2001-11-28 17:46, ToSeek wrote:
I'll save you the trouble. It's roughly 50 milliarcseconds (.05 arcseconds).



You should be able to recalculate the apparent size from the statement that it's 20,000 times smaller than the full moon. (The moon is about 0.5 degrees.)

The image is taken in ultraviolet light, so you shouldn't try to calculate the temperature based on the colors in the image.
[/quote]

Thanks, but I finally got it. The answer was found by Michaelson (!) in 1920 using pure interferometric (not imaging) methods. Reference:

http://www.eso.org/outreach/press-rel/pr-1997/pr-05-97.html

This would of course be in the visible region, where the light is definitely black body. In principle, it should lie pretty close to the answer gotten by the Hubble image.

Note that Michaelsons 1920 result was not processed by "computer technology." In some ways, this is even more convincing than Hubble imagery.

So Michaelson said 0.044 arcsec, and Hubble says 0.050 arcsec. Pretty close! No excuses now! I'll bet, knowing Michaelson and his interferometry, that his answer is closer to reality than NASA and their Hubble imagery /phpBB/images/smiles/icon_smile.gif

Tim Thompson
2001-Dec-01, 03:33 AM
Angular Diameter of Betelgeuse

Angular diameter, as a function of wavelength, from High Resolution Imaging of Betelgeuse and Mira, R.W. Wilson et al., Monthly Notices of the Royal Astronomical Society 257(3): 369-376, August 1, 1992. The angular diameter is very much wavelength dependent, because the brightness distribution over the surface is not uniform, and because of the extended atmosphere. Wavelength is in Angstrom units (reported in the paper as nanometers, as is typical for work in the infrared). The first, at 5460, is near the center of eyeball visible light. The limit of vision in the deep red will be about 7000 or so. Observations were made with a speckle interferometry mask on the 4.2 meter William Herschel Telescope (http://www.ing.iac.es/PR/wht_info/). The 7100 Angstrom measurement coincides with a TiO absorption band.

Wl diam
5460 0.057 +/- 0.002
6330 0.055 +/- 0.001
7000 0.049 +/- 0.003
7100 0.054 +/- 0.002

And another set, from another paper, New views of Betelgeuse: multi-wavelength surface imaging and implications for model hot-spot building, J.S. Young et al., Monthly Notices of the Royal Astronomical Society 315: 635-645 (2000). These values are taken from the visibility plots, and are give without stated uncertainties. They report that these are consistant with a smooth disk of 0.0514 +/- 0.0008 arc seconds. Observations by the same group, also at the William Herschel Telescope. using the Cambridge Optical Aperature Synthesis Telescope (http://www.mrao.cam.ac.uk/telescopes/coast/index.html) (COAST).

wl diam
7000 0.0470
9050 0.0478
12900 0.0426

This paper is actually much involced in doing, though in excruciating detail, much the same thing as Rosen proposes to do with the simpler equations. Using the interferometric surface image, the authors derive models for the surface brightness distribution, and discuss convective hotspot models.

The most precise measurement I know of was carried out farther in the infrared, at 11 microns (110000 Angstroms), by the U.C. Berkeley Infrared Spatial Interferometer (http://isi.ssl.berkeley.edu/), located on the grounds at Mt. Wilson Observatory (http://www.mtwilson.edu/). They observe 0.0547 +/- 0.0003 arc seconds, which is corrected for limb darkening to 0.0552 +/- 0.0005 arc seconds. This is probably a better measure of the "real" angular diameter, as I think the brightness distribution over the surface is much less likely to be nonuniform at wavelengths this long, and the atmosphere will not contribute as much here either.

At shorter wavelengths, where the star's upper atmosphere and chromosphere get into the act, Betelgeuse looks over twice as large. At 2500 Angstroms, it has an angular diameter of 0.1250 +/- 0.0005 arc seconds (can't find the paper!!).

Mifletz
2001-Dec-01, 02:28 PM
NASA's virtual photos manipulated according to crooked astronomers heliocentric, atheistic evolutionary predilections?!

http://www.fixedearth.com/nasas_hanky-panky.htm

Torsten
2001-Dec-01, 04:56 PM
Ahhh, so this is your way of stating that the images from Hubble aren't good enough for you.

Here's a snippet from your link, Mifletz:

Whether small or huge, mirrors are the heart of a telescope. The image one sees is determined by the mirrors that reflect it. Look at the caveat on the rear-view mirror on the passenger side of your car. It has this warning: "Objects In Mirror Are Closer Than They Appear". Think what can be done with this simple principle in making close stars appear far away! But that is child's play compared to distortions of reality that NASA is using in its space telescopes! The new NASA computerized telescopes embody "conical foil X-ray mirrors...affixed in a Broad Band X-Ray Telescope" and "spherical mirrors and a field flattening lens" and "pyramidal mirrors" and "parabolic mirror's effects" and "aluminized mylar thermal covers...over the mirror aperture" and "reflectivity tests on sample foils" and "tests on small mirror segments"and "back scattering from adjacent reflectors".... "Constructive Solid Geometry (CSG)...allows us to simulate perfect mirrors".... "reflective and refractive materials are used for the mirrors and lens...to make a real world simulation".... "CSG...computer code...CONSTRUCTS 3D worlds"....

So the things the author of your linked site cannot understand, or more likely, hopes that his <strike>dupes</strike> readers will not understand, are merely listed in quotes, without explanation, to appear as a wall of evil emanating from NASA. "Spherical mirrors and a field flattening lens?" Surely you joke! This is technology that appears in amateurs' scopes.

C'mon Mifletz, do you ever visit sites, other than this one, hosted by the people that do science? Or is the possiblilty that you might learn something about science too threatening to your fragile geocentric universe?

As an aside, I'm not sure if Mifletz actually believes this stuff or practices a really effective troll, but it is necessary to challenge the imbecilic notions of his linked sites whenever they appear: Last week a True Believer tried to explain to my son, ala Mifletz's argument at the old board, that grasshoppers walk on four legs.

David Simmons
2001-Dec-01, 05:08 PM
As an aside, I'm not sure if Mifletz actually believes this stuff or practices a really effective troll ...


Mifletz original question was how it was possible to detect a planetary atmosphere when even a star cannot be magnified to a disk.

My original post answered that question by directing him to a site that explained it. By now there are many more such sites available.

If he really wanted an answer he already has one and others are at hand. Doens't that make his agenda sort of obvious?

2001-Dec-02, 07:03 AM
On 2001-11-30 22:33, Tim Thompson wrote:
Angular Diameter of Betelgeuse

Wl diam
5460 0.057 +/- 0.002
6330 0.055 +/- 0.001
7000 0.049 +/- 0.003
7100 0.054 +/- 0.002

[/i], J.S. Young et al., Monthly Notices of the Royal Astronomical Society 315: 635-645 (2000). These values are taken from the visibility plots, and are give without stated uncertainties. They report that these are consistant with a smooth disk of 0.0514 +/- 0.0008 arc seconds. Observations by the same group, also at the William Herschel Telescope. using the Cambridge Optical Aperature Synthesis Telescope (http://www.mrao.cam.ac.uk/telescopes/coast/index.html) (COAST).

wl diam
7000 0.0470
9050 0.0478
12900 0.0426



Nice experimental data. Thank you, I will save and treasure this. /phpBB/images/smiles/icon_smile.gif

I was completely wrong. /phpBB/images/smiles/icon_eek.gif I thought there was a way to get the distance from the image diameter, the magnitude, and the color using black body formulas.

Turns out the luminosity of a star is proportional to the effective area of the surface. The solid angle is inversely proportional to the surface area of the star. The two effects cancel each other out. /phpBB/images/smiles/icon_frown.gif

I misunderstood spectroscopic parallax, too. To get luminosity, one needs an HR diagram. The HR diagram requires the calculation of the distances to many stars, using geometric parallax. One can't really get around geometric parallax to check the distance to a star, even if one could resolve the image at the thermal radiation peak wavelength /phpBB/images/smiles/icon_frown.gif

<font size=-1>[ This Message was edited by: Rosen1 on 2001-12-02 02:23 ]</font>

<font size=-1>[ This Message was edited by: Rosen1 on 2001-12-02 02:25 ]</font>

2001-Dec-02, 07:09 AM
I actually once met a man who refused to accept any evidence that was not visible to the unaided human eye...
Silas


Did this fellow use glasses or contact lenses, by any chance? Was he near or far sighted? Did he have any lens-correction laser-surgery done on his eyes? Was his vision perfect? /phpBB/images/smiles/icon_wink.gif

<font size=-1>[ This Message was edited by: Rosen1 on 2001-12-02 02:22 ]</font>

The Bad Astronomer
2001-Dec-02, 11:39 PM
http://www.fixedearth.com/nasas_hanky-panky.htm


Uch, this again. There is a quotation on that page of me; something I wrote for a Hubble webpage about some observations for which I did some contributions. The guy who wrote that fixedearth page doesn't understand a single thing about astronomy, and has difficulty understanding pretty simple concepts.

Linking to this page puts you on the shakiest ground yet, Mifletz. I take a very dim view of being called a liar, especially on my own website. Or did that obvious reference on the fiexedearth page escape your attention?

We won't be hearing from Mifletz any more here.