Hodge 301
Encyclopedia
Star cluster
Star clusters or star clouds are groups of stars. Two types of star clusters can be distinguished: globular clusters are tight groups of hundreds of thousands of very old stars which are gravitationally bound, while open clusters, more loosely clustered groups of stars, generally contain less than...
in the Tarantula Nebula
Tarantula Nebula
The Tarantula Nebula is an H II region in the Large Magellanic Cloud . It was originally thought to be a star, but in 1751 Nicolas Louis de Lacaille recognized its nebular nature....
, visible from Earth's Southern Hemisphere
Southern Hemisphere
The Southern Hemisphere is the part of Earth that lies south of the equator. The word hemisphere literally means 'half ball' or "half sphere"...
. The cluster and nebula lie about 168,000 light years away, in one of our Milky Way Galaxy's orbiting satellite galaxies, the Large Magellanic Cloud
Large Magellanic Cloud
The Large Magellanic Cloud is a nearby irregular galaxy, and is a satellite of the Milky Way. At a distance of slightly less than 50 kiloparsecs , the LMC is the third closest galaxy to the Milky Way, with the Sagittarius Dwarf Spheroidal and Canis Major Dwarf Galaxy lying closer to the center...
.
Hodge 301, along with the cluster R136, is one of two major star clusters situated in the Tarantula Nebula
Tarantula Nebula
The Tarantula Nebula is an H II region in the Large Magellanic Cloud . It was originally thought to be a star, but in 1751 Nicolas Louis de Lacaille recognized its nebular nature....
, a region which has seen intense bursts of star formation over the last few tens of millions of years. R136 is situated in the central regions of the nebula
Nebula
A nebula is an interstellar cloud of dust, hydrogen gas, helium gas and other ionized gases...
, while Hodge 301 is located about 150 light years away, to the north west as seen from Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
. Hodge 301 was formed early on in the current wave of star formation
Star formation
Star formation is the process by which dense parts of molecular clouds collapse into a ball of plasma to form a star. As a branch of astronomy star formation includes the study of the interstellar medium and giant molecular clouds as precursors to the star formation process and the study of young...
, with an age estimated at 20-25 million years old, some ten times older than R136.
Since Hodge 301 formed, it is estimated that at least 40 stars within it have exploded as supernova
Supernova
A supernova is a stellar explosion that is more energetic than a nova. It is pronounced with the plural supernovae or supernovas. Supernovae are extremely luminous and cause a burst of radiation that often briefly outshines an entire galaxy, before fading from view over several weeks or months...
e, giving rise to violent gas motions within the surrounding nebula
Nebula
A nebula is an interstellar cloud of dust, hydrogen gas, helium gas and other ionized gases...
and emission of x-ray
X-ray
X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...
s. This contrasts with the situation around R136, which is young enough that none of its stars have yet exploded as supernovae; instead, the stars of R136 are emitting fast stellar wind
Stellar wind
A stellar wind is a flow of neutral or charged gas ejected from the upper atmosphere of a star. It is distinguished from the bipolar outflows characteristic of young stars by being less collimated, although stellar winds are not generally spherically symmetric.Different types of stars have...
s, which are colliding with the surrounding gases. The two clusters thus provide astronomers with a direct comparison between the impact of supernova explosions and stellar winds on surrounding gases.