Planets seem to occur all over the place in the universe. However, it is still unknown how they form. The growth of objects larger than meter size is difficult because objects of this size quickly fall into the central star. This Astrobite gives a small overview of the meter-size barrier as found by Stuart J. Weidenschilling in 1977.
In today’s Astrophysical Classic, we hark back to 1987 and the introduction of a new method determining the age of the universe through the use of white dwarf stars.
Why resort to complicated theories that involve mysterious, unknown forces and states of matter? The geocentric model of the Universe nicely explains 1st century C.E. data.
Imagine a spinning skater. She pulls her arms in a little and spins faster. She brings her arms all the way into her chest, and spins really fast, and then bam! she rockets up into the sky. Seven years ago, computer simulations revealed a configuration of two spinning black holes that merged in this way, jumping out of their orbital plane with a velocity of several thousand km/s. Not only is this weird, it’s also important. We know that large galaxies host supermassive black holes at their centers. We also know that galaxies merge, presumably introducing their black holes to one another. If the newly formed black hole were to exit the galaxy entirely, it could carry its accretion disk with it, and be observable as a displaced core.
In the final months of World War II, Vannevar Bush, director of the Office of Scientific Research and Development, prepared a report that would forever shape federal support of scientific research.
Today we take a look back to 1916, when distances were measured in light years and uncertainties weren’t to be included in publications. The nearly 100-year old discovery of a small star has large implications for our understanding of stellar astrophysics, even today.
