How can I measure the distance of a star?
How does the distance of a star can be calculated by an amateur astronomer ? How has it been done in the ancient time?
Measuring distances to celestial objects is one of the hardest problems in astronomy. Even scientists sometimes have trouble figuring out how far are the objects they study!
Since we totally lack depth perception when we look at the night sky, it is impossible to tell the distance to stars just by looking at them. In fact, ancient astronomers thought that all stars were positioned at the same distance from Earth on a large hollow sphere. Only with telescopes can we start to measure distances to nearby stars. The method used is called stellar parallax.
To get a feeling of what parallax is, put your hand in front of you, and then look at it with one eye at the time. You will notice that the position of your hand with respect to the background changes. The same trick is used to measure distances to stars. To do parallax, one needs to measure to position of a star with respect to background stars at an interval of 6 months. (because 6 months is the largest distance you will get between two positions of the Earth on its orbit around the Sun). Then the parallax is the angle made by the two positions measured for the star you are interested in. These angles are very small, only small fractions of degrees in the sky, much less that you can resolve with your eye.
So unfortunately, the answer to your question is that you will not be able to measure distances to stars, unless you could have access to a telescope at a professional observatory, in which case it is still very hard to do.
Get More 'Curious?' with Our New PODCAST:
- Podcast? Subscribe? Tell me about the Ask an Astronomer Podcast
- Subscribe to our Podcast | Listen to our current Episode
- Cool! But I can't now. Send me a quick reminder now for later.
- How can we measure distances to more stars?
- How do we measure distances to other stars?
- What are the closest and/or brightest stars?
- How do you measure the distance between Earth and the Sun?
- Why don't astronomers use everyday units to measure distances (what is an AU or a pc)?
- How do astronomers measure the radius of a star?
How to ask a question:
If you have a follow-up question concerning the above subject, submit it here. If you have a question about another area of astronomy, find the topic you're interested in from the archive on our site menu, or go here for help.Table 'curious.Referrers' doesn't existTable 'curious.Referrers' doesn't exist
This page has been accessed 53330 times since October 7, 2002.
Last modified: October 8, 2002 9:29:09 AM
Ask an Astronomer is hosted by the Astronomy Department at Cornell University and is produced with PHP and MySQL.
Warning: Your browser is misbehaving! This page might look ugly. (Details)