Astronomy Picture of the Day
    


M101: The Pinwheel Galaxy
<< Yesterday 14.06.2015 Tomorrow >>
M101: The Pinwheel Galaxy
Credit & Copyright: Robert Gendler
Explanation: Why do many galaxies appear as spirals? A striking example is M101, shown above, whose relatively close distance of about 27 million light years allows it to be studied in some detail. Observational evidence indicates that a close gravitational interaction with a neighboring galaxy created waves of high mass and condensed gas which continue to orbit the galaxy center. These waves compress existing gas and cause star formation. One result is that M101, also called the Pinwheel Galaxy, has several extremely bright star-forming regions (called HII regions) spread across its spiral arms. M101 is so large that its immense gravity distorts smaller nearby galaxies.

January
February
March
April
May
June
July
August
September
October
November
December
 < June 2015  >
Mo Tu We Th Fr Sa Su
1234567
891011121314
15161718192021
22232425262728
2930




Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)
NASA Web Site Statements, Warnings, and Disclaimers
NASA Official: Jay Norris. Specific rights apply.
A service of: LHEA at NASA / GSFC
& Michigan Tech. U.

Based on Astronomy Picture Of the Day

Publications with keywords: M 101 - spiral galaxy - spiral arms
Publications with words: M 101 - spiral galaxy - spiral arms
See also:
All publications on this topic >>