Sextans A: A Seemingly Square Galaxy
Explanation:
What's bothering local galaxy
Sextans A? A small
dwarf irregular galaxy spanning 5 thousand light years across,
Sextans A is
located only 5 million light-years away.
Named for its home constellation of
Sextans, the "diamond in the rough"
structure relates to an ancient unknown event.
100 million years ago,
something mysterious started
a new wave of
star formation in Sextans A's center.
Massive short-lived stars exploded in
supernovae
that caused more
star formation
and yet more supernovae, ultimately resulting in an
expanding shell.
Today,
young blue stars
highlight areas and shell edges high in
current star formation, a shell that from
our perspective
appears roughly square.
In the
above picture, a bright orange star in our own
Milky Way Galaxy
appears superposed in the foreground.
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.
