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Discoveries of Helium Stars
In 2011, GALEX J184559.8−413827 (also known as J1845−4138) was labeled a "hot subdwarf." This means that GALEX J184559.8-413827 is characterized with being hotter and larger than the sun, while also being completely devoid of hydrogen. From these classifications, this hot subdwarf is considered to be a extreme helium star. In South Africa, the Southern Africa Large Telescope (SALT) has been monitoring this massive helium star's high-resolution spectrum.

A Hypervelocity star (HVSs) called US 708, HVS 2 has been labeled a helium star. Being the most fast rotator, it is thought to be a remnant of a thermonuclear supernova.

The helium star's great capability of transforming into other stellar objects has been observed over the years. In 2014, a helium nova named V445 Puppis exploded, along with a following explosion of the star SN2012Z, causing a high-mass transfer between the two. It is observed to have caused a growing helium star that has the potential to transform into a red giant after losing it's hydrogen envelope in the future.

Origin of Helium Stars
After a binary mass transfer, a helium star is formed. This may only happen if these 2 binary masses share the same type of envelope phase.

Merging
Often when a supernova dies, long gamma ray bursts are emitted. In 2010 it was observed that the aftermath of a supernova death caused a helium star to merge with a neuron star. This led to the merger going through a common envelope phase (losing it's hydrogen) and emitting gamma ray bursts.