Finding Distance to Sirius Using Parallax Method

In summary: He used an octant (an old fashioned instrument) to measure the angle between that star and the background. By doing this, he was able to calculate the distance to that star.
  • #1
yukkuy
3
0
how will you find the distance to the star sirius using parallax method using eath based telescpoes?

i know the distances and angle in association with the equation...but i don't get how u accuatly get those data. The very first step in achieving those data.

like for eg ...the distance is 2.63 parsecs and the parallax angle is 0.38 arcseconds...how did they actually get those data ?
i know if you find one of those data ...it will help the forumlar :)
just don't understand how they got them :)
 
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  • #2
Look at the sky - can you measure an angle between any two stars (or other objects)?
 
  • #3
Borek said:
Look at the sky - can you measure an angle between any two stars (or other objects)?

to be honest i don't really understood that
but ... measuring the angle between any two stars would be ...0? cause u can't have a angle unless there's 3 points ?
 
  • #4
You are third point.
 
  • #5
sooo...The point is at say june ...then the second point will be at around december (earth revolve ...180*)
...so that forms the baseline of my triangle, and with sirius makes the 3 . but how do i measure those angles with telescopes?
 
  • #6
It really isn't that difficult. See for example

http://en.wikipedia.org/wiki/Octant_(instrument )

Bear in mind this is an outdated instrument, designed hundreds of years ago.

There are many ways, to be honest, I have no idea which one is used routinely in todays astronomy. Probably more than one though.
 
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  • #7
I didn't follow the link above so I apologize if this is a repeat. What they do is using that base line technique as described above, they watch/measure how the star moves laterally with respect to the backround sky from each respective point in space ( measure once in June and once again in December). Using a little trigonometry you can obtain the inside angle by creating a right triangle and doubling the quantity. This can be demonstrated rather easily. If you extend your hand out directly in front of your face while holdinh your hand in a fist with your thumb up, alternate closing one eye at a time and your thumb will appear to shift positions even though your hand hasn't moved. Hope that helps.

Joe
 

1. How does the parallax method work to find the distance to Sirius?

The parallax method involves measuring the apparent shift in the position of a celestial object, such as Sirius, against the background of more distant stars. This shift is caused by the Earth's orbit around the Sun, and by measuring the angle of this shift, scientists can calculate the distance to Sirius using trigonometry.

2. What instruments are used to measure the parallax of Sirius?

Astronomers use a variety of instruments to measure the parallax of Sirius, including telescopes, cameras, and specialized instruments such as astrometric satellites. These instruments allow for precise measurements of the angle of parallax, which are necessary for accurate calculations of the distance to Sirius.

3. How accurate is the parallax method for determining the distance to Sirius?

The parallax method is considered to be one of the most accurate ways of measuring the distance to nearby stars, including Sirius. With modern technology, scientists can measure the parallax angle to within a few milliarcseconds, resulting in distance calculations with an accuracy of about 1%. This makes the parallax method a valuable tool for understanding the structure of our galaxy.

4. Are there any limitations to using the parallax method to find the distance to Sirius?

While the parallax method is highly accurate, there are a few limitations to its use. One limitation is that it can only be used for relatively nearby objects, as the angle of parallax decreases with distance. Additionally, atmospheric effects, such as refraction, can introduce errors into the measurements. To mitigate these limitations, astronomers use multiple observations and advanced techniques to improve the accuracy of their distance calculations.

5. What other information can be gathered by using the parallax method to study Sirius?

In addition to determining the distance to Sirius, the parallax method can also provide information about the motion and characteristics of the star. By observing changes in the parallax over time, scientists can measure the proper motion of Sirius, or its apparent motion across the sky. This can also reveal important details about the star's orbit and any potential companions it may have.

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