| NASA Center: |
Hubble Space Telescope Center |
|---|
| Image # : |
PR99-16 |
|---|
| Date : |
05/06/1999
|
|---|
|
Title
Ring Around a Galaxy
Full Description
Space Telescope Science Institute astronomers are giving the public
chances to decide where to aim NASA's Hubble Space Telescope. Guided by
8,000 Internet voters, Hubble has already been used to take a close-up,
multi-color picture of the most popular object from a list of
candidates, the extraordinary "polar-ring" galaxy NGC 4650A.
Located about 130 million light-years away, NGC 4650A is one of only
100 known polar-ring galaxies. Their unusual disk-ring structure is not
yet understood fully. One possibility is that polar rings are the
remnants of colossal collisions between two galaxies sometime in the
distant past, probably at least 1 billion years ago. What is left of
one galaxy has become the rotating inner disk of old red stars in the
center. Meanwhile, another smaller galaxy which ventured too close was
probably severely damaged or destroyed.
The bright bluish clumps, which are especially prominent in the outer
parts of the ring, are regions containing luminous young stars,
examples of stellar rebirth from the remnants of an ancient galactic
disaster. The polar ring appears to be highly distorted. No regular
spiral pattern stands out in the main part of the ring, and the
presence of young stars below the main ring on one side and above on
the other shows that the ring is warped and does not lie in one plane.
Determining the typical ages of the stars in the polar ring is an
initial goal of our Polar Ring Science Team that can provide a clue to
the evolution of this unusual galaxy.
The HST exposures were acquired by the Hubble Heritage Team, consisting
of Keith Noll, Howard Bond, Carol Christian, Jayanne English, Lisa
Frattare, Forrest Hamilton, Anne Kinney and Zolt Levay, and guest
collaborators Jay Gallagher (University of Wisconsin-Madison), Lynn
Matthews (National Radio Astronomy Observatory-Charlottesville), and
Linda Sparke (University of Wisconsin-Madison).
Keywords
Hubble Space Telescope HST NG 4650A Wide Field Planetary Camera WFPC Dark-Matter Nebula
Subject Category
Deep Space Studies, Hubble,
Reference Numbers
- Center:
HSTI
- Center Number:
PR99-16
- GRIN DataBase Number:
GPN-2000-000944
Source Information
- Creator/Photographer: NASA, The Hubble Heritage Team, STScI, AURA ODRing Around a Galaxy
- Original Source: DIGITAL
| Resolution | Format | Width
(Pixels) | Height
(Pixels) | Size
(KBytes) |
Thumbnail |
.jpg |
41 |
88 |
9 |
Small |
.jpg |
291 |
624 |
245 |
Medium |
.jpg |
683 |
1462 |
1,420 |
Large |
.jpg |
683 |
1462 |
1,419 |
Other relevant NASA Web sites:
• NASA Headquarters
• NASA History Office
• NASA Image eXchange (NIX)
• NASA Multimedia Gallery
• NASA Human Spaceflight
Updated October 31, 2002
• History Questions: NASA History Office
• Responsible NASA Official: Steve Garber
• Author: Michael Hahn. Editor: Dwayne A. Day
• Curator & Technical Questions: Erin Needham
• NASA's Privacy Statement
|
