Introductory Astronomy: Parallax, the Parsec, and Distances

Video lecture that discusses the concept of parallax, the unit of the parsec, and how astronomers can determine the distances to the most nearby stars.

Disclosure: some of the links in this video description are affiliate links, meaning at no additional cost to you, I may receive a commission if you click through and make a purchase.

[Sargentleman]

This didn't really explain how the parallax angle is found. How from the images in January and July do you convert that perceived motion to a parallax angle?

[charli]

But how do you measure the angle if it just looks like the star is moving side to side?

[amenalyasiry]

Very informative video, I would definitely recommend this to anyone that is interested in astronomy, pretty cool.

[vedanshpaliwal]

how do they measure the angle and why "pi" is used as the symbol for unknown

[hotmale]

Very illustrative and helpful video..Thanks a Lot..BUT:
Although, it doesn't make a difference here, it's better if SI units are used in science illustrations and not miles, feet, ounce etc.
I think it's a catastrophe to use the symbol "pi" for an unknown angle for obvious reasons.

[Jenterke]

wouldn't the background stars also move due to parallax? How then to measure the angle of parallax of the star if there is no static background to measure against?

[harryzefaa]

Excuse me but i can see that the apparent motion of a star is going to be an ellipse, but i don't understand how from that ellipse you can measure the parallax angle.

[abhishekbhattacharya]

what if the star, sun and earth do not for a right angled

[luisdiniz]

Great video! The concepts are explained in a very clear way, such details as the variable used to the inner angle or the unit of distance do not interfere to comprehend the main idea! Good job!

[ShogunDude]

Awesome video, you just tought me what four books and two videos couldn't!

[juliabudd]

This actually helped me a lot thank you so much!! :)

[alexcastillonetwork]

Even the speed of light has a incredible speed of 300, 000km /sec it would be still slow to see it's speed if it will travel across our milky way galaxy which takes 100, 000 light years accross..

[pencils]

What he failed to tell you was that a parsec is 3.26 light years, meaning that Proxima Centauri is 3.912 light years distant.

[spirit-teacher]

Absolutely the best explanation of parsec on YouTube.

[yellowhue]

What if you mimicked this on a microscopic level, under a microscope? Would it be possible to extrapolate to greater distance through considering a equation related to measurement scaling?

[aspie]

Very helpful! :))
There's one thing I want to know more about.. For example, If I know a star's parallax angle, how can I relate it to a star's RA/Dec change?
at 7:51 he says that the interior angle is the size of the entire shift… so does it mean that, change in RA and parallax angle are directly connected to each other?

[sparhopper]

Just for fun. . .
Han was wrong!
One cannot make the Kessel Run 'in' 12 parsecs (as a parsec is a unit of distance, not time). It should be: "That's the starship that made the Kessel Run 'of' 12 parsecs, 'in' x amount of time".
No?

[sabinefrank]

Vielen Dank. Nun habe ich das mal so richtig verstanden. Super

[aadityaabraham]

Thank you. That video really simplified the concept. :)

[phongluunguyen]

May I ask, what if 3 triangle tops (Earth in January, Earth in July and the nearby star) didn't form an isosceles triangle, how could we measure the distance then???