Advertisement.

EnchantedLearning.com is a user-supported site.
As a bonus, site members have access to a banner-ad-free version of the site, with print-friendly pages.
Click here to learn more.

Join Enchanted Learning
Site subscriptions last 12 months.
Click here for more information on site membership.
$20.00/year or other amount
(directly by Credit Card)
$20.00/year or other amount
(via PayPal)
$20.00/year or other amount
(for sending a check by mail)
$20.00/year or other amount
(for subscribing by school purchase order)
As a thank-you bonus, site members have access to a banner-ad-free version of the site, with print-friendly pages.
(Already a member? Click here.)

Zoom Astronomy
Astronomy Dictionary
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Click on an underlined word for more information on that subject.

BLACK HOLES
A black hole is a massive object (or region) in space that is so dense that within a certain radius (the Schwarzschild radius, which determines the event horizon), its gravitational field does not let anything escape from it, not even light.



The Formation of Black Holes:
It is thought that giant stars (those with a mass over 3 times the mass of the Sun) will evolve into a red supergiant, a supernova, and then into a black hole. The typical black holes is believed to have a mass of roughly 10 times that of the Sun, but the range must be huge. For a typical black hole with a mass 10 times that of the Sun, the Schwarzschild radius would be roughly 18.6 miles (30 km).

The Phrase Black Hole:
The phrase 'black hole' was coined by the physicist John Archibald Wheeler; before Wheeler, black holes were called 'frozen stars.' Astronomers think that there may be a black hole at the center of each galaxy.


Zoom Astronomy
Astronomy Dictionary
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Click on an underlined word for more information on that subject.
If the astronomy term you are looking for is not in the dictionary, please e-mail us.




Enchanted Learning®
Over 20,000 Web Pages.
Sample Pages for Prospective Subscribers

Overview of Site
What's New
Enchanted Learning Home
Monthly Activity Calendar
Books to Print
Site Index

K-3
Crafts
K-3 Themes
Little Explorers
Picture dictionary
PreK/K Activities
Rebus Rhymes
Stories
Writing
Cloze Activities
Essay Topics
Newspaper
Writing Activities
Parts of Speech

Fiction
The Test of Time
Biology
Animal Printouts
Biology Label Printouts
Biomes
Birds
Butterflies
Dinosaurs
Food Chain
Human Anatomy
Mammals
Plants
Rainforests
Sharks
Whales
Physical Sciences
Astronomy
The Earth
Geology
Hurricane
Landforms
Oceans
Tsunami
Volcano
Languages
Dutch
French
German
Italian
Japanese (Romaji)
Portuguese
Spanish
Swedish
Geography/History
Explorers
Flags
Geography
Inventors
US History

Other Topics
Art and Artists
Calendars
Crafts
Graphic Organizers
Label Me! Printouts
Math
Music

Click to read our Privacy Policy

E-mail


Enchanted Learning Search

First search engine with spelling correction and pictures!
Search EnchantedLearning.com for all the words:
Enter one or more words, or a short phrase.
You can use an asterisk * as a wild-card.



Zoobooks magazine for kids!
Advertisement.



Advertisement.






Copyright ©2001-2008 EnchantedLearning.com ------ How to cite a web page