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Dc2LightTech
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- TL;DR Summary
- measuring astronomical distanced
using the Earths orbit, what is the maximum distance that can be measured using parallax error?
What accuracy/precision?Dc2LightTech said:TL;DR Summary: measuring astronomical distanced
using the Earths orbit, what is the maximum distance that can be measured using parallax error?
How high is up?Dc2LightTech said:using the Earths orbit, what is the maximum distance that can be measured using parallax error?
Now you have a good question. What research have you done? What have you found so far?Dc2LightTech said:using the orbit around the sun, with current technology, how far can the best optical telescopes detect and parallax shift of a star using a distant galaxy as a reference for infinity.
It isn't as simple as resolution, by the way. If you have a diffraction-limited telescope, the Rayleigh criterion will give you the ballpark for the angular separation needed to see two distinct points rather than one, and that's roughly what you need here - you need to be able to compare two images and say "yup, that point is in a different place". The figure comes out in radians. Convert to arcseconds, and one upon that is the number of parsecs you can use the method to.Dc2LightTech said:using the orbit around the sun, with current technology, how far can the best optical telescopes detect and parallax shift of a star using a distant galaxy as a reference for infinity.
I suspect they usually aren't.Ibix said:Note that ground based telescopes may not be diffraction limited due to atmospheric conditions.
if knew the pixel/angular resolution of the best sensor. and the typical Pixel/cross section for a faint star then calculation is not a hard thing to do. should be easy in LabView. I did a orbital flight dynamics program in Labview for fun. Moon landing from unlocking in orbit to touchdown. this should be easy. might be easy to simulate it.phinds said:Now you have a good question. What research have you done? What have you found so far?
Of course he did. He told us to find the answer for him!phinds said:. Have you actually researched your question?
You could certainly build a CCD with 50 nm pitch, and maybe even 5 nm, although I have no idea how you would power it up without it bursting into flames - each square cm would have 4 trillion channels.Dc2LightTech said:if knew the pixel/angular resolution of the best sensor
The maximum distance for using parallax in astronomy is typically up to a few thousand parsecs. The precision of current instruments like the Gaia satellite allows for accurate measurements of stellar parallax for stars up to about 10,000 parsecs away, though the most precise measurements are generally for distances less than 1,000 parsecs.
Parallax accuracy decreases as the distance to the object increases. This is because the parallax angle (the apparent shift in position of an object when viewed from different points) becomes smaller and more difficult to measure accurately at greater distances. Technological limitations in measuring extremely small angles also contribute to reduced accuracy at larger distances.
Advancements such as the launch of the Hipparcos and Gaia space observatories have significantly extended the range of distances where parallax can be accurately used. These satellites are equipped with high-precision instruments capable of measuring the tiny angles of stellar parallax at greater distances than was possible with earlier, ground-based technology.
The fundamental limit, based on current technology such as the Gaia satellite, is around 10,000 parsecs. Beyond this distance, the parallax angles become so small that they are exceedingly difficult to measure accurately even with the most advanced current instrumentation.
Yes, beyond the range of parallax, astronomers use other methods to measure distances. These include standard candles like Cepheid variables and Type Ia supernovae, which have known luminosities that can be used to calculate their distances from their apparent brightness. Additionally, the redshift of galaxies is used to estimate distances on an even larger scale, applicable to cosmological distances.