The Tarantula Nebula, also called 30 Doradus, is the brightest star-forming region in our part of the galaxy. It’s in the Large Magellanic Cloud (LMC) and contains the most massive and hottest stars we know of. The Tarantula Nebula has been a repeat target for the Hubble since the telescope’s early years.
Kilonovae are extraordinarily rare. Astronomers think there are only about 10 of them in the Milky Way. But they’re extraordinarily powerful and produce heavy elements like uranium, thorium, and gold.
Usually, astronomers spot them after they’ve merged and emitted powerful gamma-ray bursts (GRBs.) But astronomers using the SMARTS telescope say they’ve spotted a kilonova progenitor for the first time.
A team of astrophysicists has discovered a binary pair of ultra-cool dwarfs so close together that they look like a single star. They’re remarkable because they only take 20.5 hours to orbit each other, meaning their year is less than one Earth Day. They’re also much older than similar systems.
The death of a star is one of the most dramatic natural events in the Universe. Some stars die in dramatic supernova explosions, leaving nebulae behind as shimmering remnants of their former splendour. Some simply wither away as their hydrogen runs out, billowing into a red giant as they do so.
But others are consumed by behemoth black holes, and as they’re destroyed, the black hole’s powerful gravity tears the star apart and draws its gas into a donut-shaped ring around the black hole.
Something extraordinary happens about every 10,000 to 100,000 years in galaxies like the Milky Way. An unwary star approaches the supermassive black hole (SMBH) at the galaxy’s center and is torn apart by the SMBH’s overpowering gravity. Astronomers call the phenomenon a tidal disruption event (TDE.)
Usually, a TDE spells doom for the star as its gas is torn away into the black hole’s accretion ring, causing a bright flaring visible for hundreds of millions of light years. But researchers have found one black hole that’s playing with its food.
MWC 349A is a star about 3,900 light-years away in the constellation Cygnus. It’s huge, about 38 times as massive as the Sun. It’s actually a binary star and may even be a triple star. It’s an oddball and one of the brightest sources of radio emission in the sky.
One of the star’s unusual features is its natural maser. MWC 349A’s natural maser played a central role in a new discovery: the young star emits a blistering jet of material travelling at 500 km/sec (310 m/sec.) That discovery could help astronomers understand massive stars and their complexity.
Astronomers are keenly interested in red dwarfs and the planets that orbit them. Up to 85% of the stars in the Milky Way could be red dwarfs, and 40% of them might host Earth-like exoplanets in their habitable zones, according to some research.
But there are some problems with their potential habitability. One of those problems is tidal locking.
When a flash of light appears somewhere in the sky, astronomers notice. When it appears in a region of the sky not known to host a stellar object that’s flashed before, they really sit up and take notice. In astronomical parlance, objects that emit flashing light are called transients.
Earlier this year, astronomers spotted a transient that flashed with the light of a trillion Suns.
Young protostars are wrapped in what could be called a womb of gas and dust. The gas and dust nearest to them form a circumstellar disk as the stars grow. The disk is a reservoir of material that the star accretes as it grows.
But these stars don’t feed in a predictable rhythm. Sometimes, they experience feeding frenzies, periods of time they accrete lots of material from the disk at once. When that happens, they flare in bright bursts, “burping” as they absorb more material.