Summer Stars
Written by Greta Holsten - Illustrated by Anne Zimanski
"Imagination is more important than knowledge."
attributed to Albert Einstein
Fun Facts For kids
Compare the Stars in the Story
Visible from the northern hemisphere, the Summer Triangle is a large asterism* that includes the alpha stars of three constellations, Aquila, Lyra and Cygnus. It's named for it's beautiful placement in the eastern sky on midsummer evenings. For most northern latitudes it's easy to spot in the east in summer, and in the southwest or west in late autumn, but with the angle reversed.
*Asterism is an identifiable grouping of stars
THE SUN (aka Sol)
Our star: Is in the Milky Way Galaxy
Colour: Yellow
Distance: "Our nearest star", 8 light minutes or 1 Astronomical Unit (AU*)
Mass: An average sized star, Two million trillion trillion kilograms
Diameter: 1.4 million kilometres
Luminosity*: 400 trillion trillion watts
* 1 AU is 149,597,871 km, Earth's mean distance from the Sun.
* Luminosity is the actual brightness of a star, compared to the visual brightness of a star to an observer on Earth.
ALTAIR (al - tair)
Alpha Aquilae: 12th brightest from Earth
Constellation: Aquila, the Eagle
Colour: White
Distance: "Very far away", Almost 17 light years* (16.7 ly)
Mass: "A big star", Almost 2 times heavier than the Sun (1.8)
Diameter: Almost 2 times bigger than the Sun (1.7)
Luminosity: 10+1/2 times brighter than the Sun (10.6)
* 1 light year in distance, is 63,000 times further away than the Sun!
* Light Year, the distance light travels in a year is, 63, 240 AU or 9.4 trillion kilometres.
VEGA (vay - ga)
Alpha Lyrae: 5th brightest from Earth
Constellation: Lyra, the Lyre (or Harp)
Colour: White with a blue tinge
Distance: "very, Very far away", 25 light years
Mass: "A great big star", Almost 2+1/2 times heavier than the Sun (2.3)
Diameter: Almost 3 times bigger than the Sun (2.75)
Luminosity: 36 times brighter than the Sun
DENEB (den - ebb)
Alpha Cygni: 19th brightest from Earth
Constellation: Cygnus, the Swan
Colour: White with a blue tinge
Distance: "very, Very, Very far away", 1,425 light years
Mass: "A supergiant star", 16 times heavier than the Sun
Diameter: 114 times bigger than the Sun
Luminosity: Almost 54,000 times brighter than the Sun (54,400)
http://stars.astro.illinois.edu/sow/deneb.html
More fun facts about the summer triangle and our galaxy in this 2009 article by Astro Bob,
Facts sourced with permission. Jim Kaler, Prof. Emeritus of Astronomy, University of Illinois.
Star characters by Anne Zimanski