Category: Ars Technica
-
Do newer stars in globular clusters die before they get old?
According to theories of star life cycles, when a typical star exhausts its hydrogen fuel, it goes through a set of end-life stages before expiring, expanding and contracting over time. However, a new analysis of a globular cluster orbiting the Milky Way found that the younger generation of stars didn’t seem to reach the later…
-
New distance measurements solve one mystery – and create a new one
SS Cygni is a special kind of binary system, consisting of a red dwarf star and a white dwarf. According to theoretical models, the white dwarf strips gas from its companion, which leads to periodic outbursts of intense light: a recurrent nova. However, previous observations of the system placed it too far away for those…
-
Early galaxies: live large, die big, burn bright
How did the biggest galaxies form? Based on the ages of stars inhabiting them, the largest elliptical galaxies — those kind of boring egg-shaped clouds of stars with no pretty spiral arms — formed fairly early in the history of the Universe. While smaller elliptical galaxies likely are the modern version of submillimeter bright galaxies…
-
What goes up, must come down…except maybe antimatter
Gravity is a universally attractive force, at least as far as we can tell. However, some physicists have posited that antimatter behaves the opposite way, as though they have negative mass. Testing that hypothesis is remarkably hard, though: antimatter particles annihilate with their regular matter partners if they encounter each other (at low speeds at…
-
General relativity holds up under extreme gravity test
The general theory of relativity is the reigning champion of gravitational theories: it’s withstood tests in the Solar System, near black holes, and in binary systems. Most recently, astronomers performed detailed observations of a pulsar-white dwarf binary system, which provided an exquisite example of general relativity in action. Pulsars and white dwarfs are both the…
-
I went to a rocket test launch, and all I got was this stupid name tag
Most major American rocket launches have been from Florida, which means I’ve never had a real opportunity to see one. However, NASA’s Wallops Flight Facility is beginning to host orbital rocket launches, in collaboration with the private company Mid-Atlantic Regional Spaceport (MARS). (Historically, Wallops has launched suborbital rockets and balloons.) So, I trekked over to…
-
Green Peas were all my joy, galaxies were my delight
Most galaxies are somewhat red or blue in appearance, depending on the populations of stars that comprise them. However, citizen scientists working with the GalaxyZoo project identified a previously unknown type of galaxy: Green Peas, so named because they are small and green. The color comes from ionized oxygen, a particular form of emission that…
-
Death of a white dwarf, 10 billion years later
White dwarfs are the remnants of the cores of stars like our Sun. They have the mass of a star packed into the volume of Earth, but when they die, their light can be detected across the observable Universe. Researchers using the Hubble Space Telescope identified the farthest white dwarf supernova yet seen, one which…
-
Black hole sez: I maded you a planet, but I eated it
Let the record show: I am the first writer for Ars Technica to use the phrase “om nom nom”. Astronomers caught a supermassive black hole in the act of disrupting and devouring part of a large planet or small brown dwarf (a starlike object that isn’t massive enough for nuclear fusion). The giveaway was a…
-
Much ado about nothing in today’s dark matter non-announcement
OK, I might be feeling a little cranky about this, but my article for Ars Technica is a little more measured. I’ll have a longer analysis for Galileo’s Pendulum tomorrow, for those who want it. The short version: the Alpha Magnetic Spectrometer (AMS-02) is a particle detector installed on the International Space Station. For several…
Bowler Hat Science 