A new paper in Astronomy and Astrophysics heralds the discovery of a yellow hypergiant star known as HR 5171. Such stars are exceedingly rare, with only 12 such stars known to exist within our galaxy.
Second Generation
A new star has been discovered that was born from the very first stars of the universe. We can identify it by its particularly low metallicity.
Give and Take
How do we determine the mass of a star? One way is to look at the motion of binary stars. Their motion due to their mutual attraction allows us to calculate their masses by their orbits.
When Stars Collide
The traditional view of Type Ia Supernovae is that they are caused by the explosion of a white dwarf after it reaches the Chandrasekhar limit. But new data shows that these supernovae are actually due to the collision of two white dwarfs.
Destiny
The evolution of a star depends mainly upon its mass. There are other factors such as metallicity that can affect a star’s evolution, but the main factor is mass. It is the mass of a star that determines its destiny.
Stella Nova
The appearance of this new star, or stella nova as it was known in Latin, was a major discovery. The prevailing view at the time was that the stars were fixed and unchanging. Planets wander through the sky and comets appear from time to time, but the stars were eternal. Tycho’s observations demonstrated this was not the case, and it spurred a new interest in making accurate measurements of the heavens.
Alpha Centauri has a Posse
When we started looking for extrasolar planets, Alpha Centauri was high on the list of any astronomer’s inner child. But despite its closeness, finding planets there would be difficult. The orbit of Alpha Centauri B is at an angle relative to us, so there isn’t likely to be any transiting planets that we can detect. That means planets would have to be found by looking at the wobble of the star as the planet orbits it, which is much harder to measure.
A Short Period
In the center of our galaxy, only 27,000 light years away, lies a supermassive black hole. Some of the strongest evidence of this black hole is the observation of stars closely orbiting it. Recently in Science a new star, S0-102, was announced with an period of 11.5 years.
Order and Chaos
How do you deal with chaos in computational astrophysics? It turns out there are ways to analyze the properties of a solution even if you don’t know what the exact solution is.