Light
99. and dark
Surrounded by bright stars, towards the upper middle of the frame we see a small
young stellar object (YSO) known as SSTC2D J033038.2+303212. Located in the
constellation of Perseus, this star is in the early stages of its life and is still forming into a
fully grown star. In this view it appears to have a murky chimney of material emanating
outwards and downwards, framed by bright bursts of gas flowing from the star itself.
This fledgling star is actually surrounded by a bright disc of material swirling around it as
it forms — a disc that we see edge-on from our perspective.
However, this small bright speck is dwarfed by its cosmic neighbour towards the
bottom of the frame, a clump of bright, wispy gas swirling around as it appears to
spew dark material out into space. The bright cloud is a reflection nebula known as
[B77] 63, a cloud of interstellar gas that is reflecting light from the stars embedded
within it.
These stars are lighting up the surrounding gas and sculpting it into the wispy shape
seen in this image. However, the most dramatic part of the image seems to be a dark
stream of smoke piling outwards from [B77] 63 and its stars — a dark nebula called
Dobashi 4173. Dark nebulae are incredibly dense clouds of pitch-dark material that
obscure the patches of sky behind them.
Credit: ESA/Hubble & NASA
Stellar sneezing fit
100.
Look at the bright star in the middle of this image. Achoo! It has just
sneezed. This sight will only last for a few thousand years — a blink of an eye
in the young star’s life.
If you could carry on watching for a few years you would realise it’s not just
one sneeze, but a sneezing fit. This young star is firing off salvos of superhot, super-fast gas before it finally exhausts itself. These bursts of gas have
shaped the turbulent surroundings, creating structures known as HerbigHaro objects.
These objects are formed from the star’s energetic “sneezes”. These
salvos can contain as much mass as our home planet, and cannon into
nearby clouds of gas at hundreds of kilometres per second. Shock waves
form, such as the U-shape below this star. Unlike most other astronomical
phenomena, as the waves crash outwards, they can be seen moving
across human timescales. Soon, this star will stop sneezing, and grow up to
be a star like the Sun.
Credit: ESA/Hubble & NASA