Space 01
How Do We Know How Far Away Stars Are? Parallax Math
Proxima Centauri shifts 0.768 arcsec a year, which puts it 4.2465 light-years away. Here is the parallax math, what Gaia changed and the distance ladder.
stars
Space 02
How Bright Will Betelgeuse's Supernova Be? The Math
Betelgeuse's supernova should peak near magnitude -10 to -11: about 250 times Venus and a seventh of the full Moon. The magnitude math, step by step.
Space 03
Why stars twinkle—and why planets sometimes break the rule
A star can look restless while its light is steady. Follow the light through moving air, see why planetary disks average out much of the effect, and try a careful skywatching comparison.
Space 04
Why massive stars live fast: mass, lifetime and stellar remnants
Estimate main-sequence lifetimes from mass and luminosity, read an H–R diagram, and distinguish schematic evolution paths from detailed stellar predictions.