If the object really is Planet Nine, it would be larger than Neptune and exist 700 times further from the sun than Earth.

But, in order for astronomers to be sure about distances within our galaxy, they needed a more direct way to measure distances to Cepheids. The stellar parallax method is another way to measure ...

but the distances in miles which correspond to these parallax determinations tax the imagination to conceive. The contributions of astronomy in interpreting the sky and the earth's plane in the ...

She explains how astronomers measure star distances using parallax, rate stellar brightness, study stars through light waves, classify galaxies by shape, and detect black holes through ...

Astronomers have long speculated about an unseen planet lurking in the solar system's outer edge. This hypothetical world, dubbed Planet Nine, could explain the unusual clustering ...

The difficulty results from the lack of parallax with only one eye. Have advanced students use astronomy reference books to pick a constellation and identify by name the stars in the constellation.