A planet X around a star S

The diagram shows an approximate orbit of a planet X around a star S.

KeplerProblem

Which of the following statements is false?

(a) The planet moves in an ellipse with the star at one focus.
(b) The planet moves at the same speed at points A and C.
(c) The planet moves fastest at point D.
(d) The potential energy of the planet changes during the orbit.

 

Continue reading

Advertisements

Will there be a time when new stars will not form?

image

Image Credit: ‪‎NASA‬, ESA, the Hubble Heritage Team (STScI/AURA), A. Nota (ESA/STScI), and the Westerlund 2 Science Team

Continue reading

Excessive twinkling of stars indicates rain or snow

starsExcessive twinkling of stars indicates heavy dews, rain, snow or stormy weather in the near future. Why?

 
 
 
Continue reading