Matrix Software Home
Your Shopping Cart  |          
Matrix Software Home
Professional
Software
Blue*Star Pro
Web Service
Win*Star V6.0
NEW Sirius 2.0
NEW Kepler 8.0
Forecasts
Astro*Search
Calendars
Report Pro.
Personal
Software
Blue*Star
Win*Star Express
NEW Pegasus
Biorhythms
KNOW Series
Tarot Personal
Report Personal
Reportes Espaņol
Starter Pack
Report Writers
Software
Jupiter Report
Togetherness
Time Together
Birthday
Astro*Talk
Relationships
Forecasting
Solar Return
Lunar Return
Midpoint Keys
Make Money
Home Business
Pro Package
Home Business


Books
Paperbacks
FREE E-Books
Single Reports
Personal Readings
Natal Report
Forecast
Relocation
Child Report
Timeline
Just for Women
Solar Return
Relationship
Past Lives
Solar Arc
Free Oracle
The Matrix Oracle
Tarot
Natal Astrology
Relationships
Runes
Fortune Cookie
Electric Almanac
Numerology
I-Ching
Yes/No Oracle
Word Oracle
Community
Press to view all ^
Astrology Blogs
Interviews
Ask Astrology
Astro Dialogues
Find an Astrologer
Astro Links
Book Reviews
Articles
Celebrity Search
Astro*Talk Bulletin
Free Stuff
Fun Things to Do
NEW Sky Reader
Celebrity Search
Free Desktops
Learn Astrology
Astro Links
Monthly Planets
Today's Chart
Registered User
Matrix Customers
Quick Fixes


On Sale Now
Matrix Software List
Cosmic Patterns Software List

Matrix Astrology Software

  Beginning Astrology                  
  Your Sun Sign                           
  Astrology Articles                     
  Astrology Book Reviews          
  Astro Outline                             
  Visual Astrology                      
    Astrophysical Directions
  Astrology Organizations           


 
Matrix Software > Learng Astrology > Astrophysical Directions > Star Clusters & Nebulae > Planetary Nebulae

Learn Astrology

Back to Star Clusters & Nebulae   |   Back to Astrophysical Direction 

Planetary Nebulae

A Planetary Nebula, in essence, appears to be a roughly spheroidal or ellipsoidal shell of gas with a nuclear star in or close to its center. These nebulae (planetaries) received their name not due to any possible generic relationship to planets, but because early observers, while searching for planets with primitive telescopes, sometimes came across these disc-like objects and they at first glance looked like planets. The central star of a planetary is usually quite dim. It is not often brighter than eleventh magnitude and it is the exception that can be seen at all. The body or expanded shell-like ring of gas of the nebula is also faint and tends to blend into the sky background. The hot central stars in these nebulae seem to be evolving to the white-dwarf stage and radiate by far the greatest portion of their energy in the far ultraviolet portion of the electromagnetic spectrum. Since these objects are expanding, they are probably short-tem and will disappear as a result of expansion in something like 30,000 years. The Ring Nebula in Lyra is perhaps the best known of the planetaries. The Crab Nebula, while often considered as an example of this category, is not a true planetary, but rather the remains of a massive supernova, the ghost of a cosmic fireworks.

Copyright (c) 1997-99 Michael Erlewine


Home  |  Software  |  Learn Astrology  |  Free Stuff  |  Privacy Policy  |  Security   |  About Us   |  Contact Us   |  Site Map  |  F.A.Q.

Matrix SoftwareMatrix Software License Agreement