newhorizons

Re: Problems with the Heliocentric Model
« Reply #120 on: August 18, 2019, 07:19:54 PM »
Your history link Tom makes for interesting reading.  From a quick glance I would say that particular document dates to about the mid 19th century. Given the choice between what that says and the data obtained from the GAIA satellite I think I know which option I would choose.  How about you?

What garygreen says makes complete sense and provides a very clear explanation as to why these errors that produce apparent -ve parallaxes occur.

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Offline Tim Alphabeaver

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Re: Problems with the Heliocentric Model
« Reply #121 on: August 18, 2019, 09:20:52 PM »
If true, then there are thousands of stars exhibiting negative parallax.
I just looked this up myself in the 'Hipparcos, the New Reduction' catalogue. There are 23,000 results when I filter parallax >10 mas, and only 168 results when I filter for parallax of <-10 mas. This number goes down to 50 results (0.04%) when I filter <-20 mas, which was the test used in your quoted text before.

It looks like this problem goes away when you look at more recent, accurate catalogues. This is consistent with it being caused by uncertainty in observations.
**I move away from the infinite flat plane to breathe in

newhorizons

Re: Problems with the Heliocentric Model
« Reply #122 on: August 18, 2019, 09:39:55 PM »
Tom,

You state in your earlier post that an astronomer in the article that your link to (mid 19th century?) mentions that the star Gamma (Y) Daconis shows a large negative parallax.  There are several other descriptions of this star (assuming that is the star you mean, also known as Eltanin) which seem to offer a different view on this.  For example...

https://www.universeguide.com/star/eltanin

It actually quotes two different parallax measurements spaced 10 years apart.  The figures are given towards the end of the page.  You will appreciate that an angle of just a few milli (thousandths of) arc seconds is very small and would be extremely difficult to measure with the kind of equipment available to an astronomer in the mid 1850s so it is no wonder he struggled.


Just noticed... I think the article in your link was actually published in 1902.  Makes no difference though... to my case stated above.

Related to the topic of stellar parallax, I note it states in FE Wiki,

Quote
Firstly, we must understand that the stars in FE are small and a few thousand miles above the sea level of the earth. This change in distance compared to RE figures is due to an adjusted astronomical parallax on a Flat Earth. The angle of stellar parallax changes, as it does with the sun, when the earth is assumed to be a flat surface.

We should actually understand that the stars are neither small or just a few thousand miles away. They might need to be for FE theory to work but in reality they are not and astronomers have got good evidence to show that they are not.   Secondly... solar parallax?  How does that work since we don't need parallax to work out the distance of the Sun?
« Last Edit: August 18, 2019, 10:04:18 PM by newhorizons »

Re: Problems with the Heliocentric Model
« Reply #123 on: August 19, 2019, 08:33:20 AM »
The author of that linked article does state that the calculations of proper motion , and others (all items in red ) , could be incorrect so why should they be accepted as correct ?

newhorizons

Re: Problems with the Heliocentric Model
« Reply #124 on: August 19, 2019, 08:58:44 AM »
Are the quoted figures for the parallax measurements shown in red?

I think you will find the only estimated or calculated values are those for radius and temperature.
« Last Edit: August 19, 2019, 09:02:02 AM by newhorizons »

Re: Problems with the Heliocentric Model
« Reply #125 on: August 19, 2019, 09:53:25 AM »
My mistake - I read that as saying " The items in red "  and the paragraphs headings for  radius , temp , radial velocity and proper motion are all in red .

newhorizons

Re: Problems with the Heliocentric Model
« Reply #126 on: August 19, 2019, 11:02:53 AM »
Agreed the author should have used a different color for the text labelling sub-headings but the descriptions before where it says 'visual facts' explains which values are calculated or estimated. Those for parallax are not among them.

Its amazing to think satellites can now measure parallax angles down to a few milliarc seconds. GAIA is set to produce the most detailed ever 3D map of the Milky Way Galaxy. A friend of mine works at E2V, the company involved in designing and building the cameras on board GAIA. He was in the team that lab tested the prototype chips. Biggest chip array I have ever seen!