Credit:NASA, ESA, and S. Smartt (Queen's University Belfast)
Acknowledgement: Brian Campbell
Acknowledgement: Brian Campbell
In this new Hubble image, we can see an almost face-on view of the
galaxy NGC 1084. At first glance, this galaxy is pretty unoriginal. Like
the majority of galaxies that we observe it is a spiral galaxy, and, as
with about half of all spirals, it has no bar
running through its loosely wound arms. However, although it may seem
unremarkable on paper, NGC 1084 is actually a near-perfect example of
this type of galaxy — and Hubble has a near-perfect view of it.
NGC 1084 has hosted several violent events known as supernovae —
explosions that occur when massive stars, many times more massive than
the Sun, approach their twilight years. As the fusion processes in their
cores run out of fuel and come to an end, these stellar giants
collapse, blowing off their outer layers in a violent explosion.
Supernovae can often briefly outshine an entire galaxy, before then
fading away over several weeks or months. Although directly observing
one of these explosions is hard to do, in galaxies like NGC 1084
astronomers can find and study the remnants left behind.
Astronomers have noted five supernova explosions within NGC 1084 over
the past half century. These remnants are named after the year in which
they took place — 1963P, 1996an, 1998dl, 2009H, and 2012ec.
The most recent explosion, 2012ec, was detected at the end of NGC
1084’s top right arm in August 2012. It is not visible here as these
images were taken in 2001, some eleven years before this supernova
exploded.
Astronomers at Queen's University Belfast have managed to use
these "before" images to directly identify
the star that exploded. It appears to be a red supergiant some 10 to 20
times more massive than the Sun, and quite similar to the well-known
star Betelguese in Orion.
A version of this image was entered into the Hubble's Hidden
Treasures image processing competition by Flickr user Brian Campbell (Sinickel).
Source: ESA/HUBBLE - Space Telescope
