## mathslover The nearest star to our solar system is 4.29 light years away. How much is this distance in terms of parsecs? How much parallax would this star (named Alpha Centauri) show when viewed from two locations of the Earth six months apart in its orbit around the Sun? one year ago one year ago

1. mathslover

OK so I had done the first part but I am confused with the second one. 1.3333... pascal is the answer for 1st part. @hartnn @Algebraic! @sauravshakya

2. mathslover

@vishweshshrimali5

3. mathslover

@hartnn any idea?

4. hartnn

nopes,seen such question for the first time.

5. mathslover

well I can remind you that it is "parallax method"

6. vishweshshrimali5

7. henpen

$4.26ly=(3*10^8)(365.25*24*60*60)m=9.467*10^{15}m$$1psc=3.09*10^{16}m$ $4.26ly=\frac{9.467*10^{15}}{3.09*10^{16}}psc=0.306psc$

8. mathslover

$\large{4.29 ly = 9.46*10^{15}m * 4.29 = 40.5834*10^{15} = 4 * 10^{16} m }$ $\large{4.29 ly = \frac{4*10^{16}}{3*10^{16}}=\frac{4}{3}=1.3333...}$

9. mathslover

$$\large{1ly = 9.46*10^{15}m}$$

10. mathslover

@henpen You have done a mistake there, you forgot to multiply 4.29 there and you by fault wrote 4.26 ly ..

11. henpen

Oh yes- just multiply the end result by 4.26

12. henpen

*.29

13. mathslover

so the answer is 1.33... ?

14. mathslover

*1.33... pascal ?

15. henpen

parsecs

16. mathslover

lol sorry forgot that but still m i correct with the solution given above?

17. henpen

Yes. As to the parallax, the earth sun distance *2 is 3*10^11 m, so just use trigonometry to work out the angle change

18. mathslover

I tried that by applying the formula (parallax formula) : d = b / theta but I was unable to complete it... to the correct answer Can you show your work? or just answer you get so that I can check it with the correct answer... (I am not wanting a direct answer but here I want to check it so please provide your answer )

19. mathslover

In short : what r u getting after doing that @henpen

20. henpen

|dw:1348407871723:dw| Multiply by 2 for the change

21. henpen

Actually, don't multiply by 2|dw:1348408141213:dw|. Take the answer away from 90, and multiply THAT answer by 2.

22. henpen

2*(90-arctan(8*10^5 /3)) http://web2.0calc.com/

23. henpen

0.00042971834596

24. henpen

If parallax is measured in degrees, that is.

25. mathslover

Yes that is absolutely *correct* @henpen good work

26. mathslover

Thanks