Distance to stars from my house using the parallax technique?

  • Context: Undergrad 
  • Thread starter Thread starter Stratosphere
  • Start date Start date
  • Tags Tags
    Parallax Stars
Click For Summary

Discussion Overview

The discussion revolves around the feasibility of measuring the distance to stars from a residential location using the parallax technique. It explores the necessary conditions, limitations, and technical requirements for such measurements, with a focus on the time frame for observations.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant questions whether it is possible to measure distances to stars from home using the parallax technique and inquires about the proximity of stars required for measurements within a month.
  • Another participant explains that a star at a distance of 1 parsec displays a parallax of 1 arcsecond, indicating that no stars are closer than this, making measurements in a month impractical without significant resolving power.
  • There is a suggestion that typical stars would yield a parallax of about 1/50 of an arcsecond for monthly measurements, which may be beyond the capabilities of amateur astronomers.
  • One participant expresses skepticism about the ability to measure distances requiring longer time frames, noting that annual parallaxes are generally less than one arcsecond, and achieving even 1/10 of an arcsecond is optimistic.
  • Another participant highlights the challenges posed by atmospheric conditions, which limit resolution to about 0.5 arcseconds, complicating precise measurements for amateurs.
  • One participant provides a mathematical perspective, explaining the geometry involved in parallax measurements and the need for accurate instruments to measure small angles.
  • A humorous remark is made about the dependency of measurements on the width of the house, suggesting a light-hearted take on the technical discussion.

Areas of Agreement / Disagreement

Participants generally agree on the challenges and limitations of measuring stellar distances using the parallax technique from a residential location, but there is no consensus on the feasibility of such measurements or the specific requirements needed.

Contextual Notes

The discussion highlights limitations related to atmospheric conditions, the precision of instruments required, and the inherent challenges of measuring small angles in amateur settings.

Stratosphere
Messages
373
Reaction score
0
Is it possible to find the distance to stars from my house using the parallax technique? If I can how close does a star have to be to be measured in a month instead of six months?
 
Astronomy news on Phys.org


Stratosphere said:
Is it possible to find the distance to stars from my house using the parallax technique? If I can how close does a star have to be to be measured in a month instead of six months?

If I didn't know any better I'd say you were trying to do this yourself.

A star at a distance of 1 pc displays a parallax of 1 arcsecond. There are no stars closer than 1pc, so even the nearest are going to display a parallax siginificantly smaller than 1 arcsecond. And these are annual parallax numbers. If you want to try the measurements in only a month, you can expect much smaller parallaxes, on the order of 1/50 of an arcsecond for typical stars.

So, unless you have that kind of resolving power, I'd say it's out of the question.
 


So would I be able to measure things that would require a longer amount of time?
 


Stratosphere said:
So would I be able to measure things that would require a longer amount of time?

Probably not. Like I said annual parallaxes are going to be less than one arc second. Significantly less, but it's probably even optimistic to hope to get some in the neighborhood of 1/10 of an arcsecond. Annually. Also, given the fact that even under the best of seeing conditions the Earth's atmosphere limits resolution to about .5 arcseconds, it seems a daunting task indeed.

Getting down to .5 arcseconds isn't actually that hard, and only requires a ~8-10 inch diameter telescope. But taking precise enough measurements to detect the parallax, owing to the damned atmosphere, would be near impossible for an amateur (I think).
 


You can do the math with simple trigonometry. The diameter of the Earth's orbit around the sun is approximately 186 million miles [a very convenient number - 1000 light seconds]. That forms the base of the parallax triangle you have to work with. One light year works out to around 6 trillion miles - a pretty large number compared to the diameter of Earth's orbit. You need a very accurate [and expensive] devise to reliably measure such small angles.
 


OK, these answers are better than mine. Which was going to be 'Depends on how wide your house is'.
 

Similar threads

  • · Replies 7 ·
Replies
7
Views
3K
  • · Replies 14 ·
Replies
14
Views
2K
  • · Replies 0 ·
Replies
0
Views
1K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 29 ·
Replies
29
Views
6K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 3 ·
Replies
3
Views
4K