Astronomy Picture of the Day
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
2002 August 4 
Posted on 08/03/2002 10:54:41 PM PDT by petuniasevan
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
2002 August 4
Explanation: NGC 2997 is a grand design spiral galaxy. Its small nucleus and sprawling spiral arms give it a type Sc designation. NGC 2997, pictured above, is speeding away from us at about 1100 kilometers per second, which would place it at about 55 million light years distant, given current estimates of the expansion rate of our universe. NGC 2997 is thought to have a mass of about 100 billion times that of our Sun, but is probably less massive than our own Milky Way galaxy. NGC 2997 is not seen face-on - it is thought tilted by about 45 degrees. NGC 2997 is particularly notable for a nucleus surrounded by a chain of hot giant clouds of ionized hydrogen.
Bright, hot young blue stars (massive and short-lived) trace out the spiral structure in such galaxies. Their lives are too short for them to move far from their origin in the dust and gas clouds that make up most of the mass in the arms.
Get on the APOD PING list! 
I didn't know you were the eye inside of me
You were a secret essence both in body and soul
I asked you show me a symbol of you in this world
Suddenly I realized you were the whole universe.
~ Yunus Emre &;-)
Rules are rules in life
Not made to be broken or
trifled with by men.
Cote has a class for
all aspiring poets here.
Belvedere beckons.
©2002 2Trievers
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.