Gifs from Chris Hadfield’s Space Oddity [X]
Respect and love to this man. One of the finest commanders the ISS has seen and which we’ve all shared in his journey. Thank you, Sir Chris Hadfield, for your amazing photography and continual public outreach for the scientific community. Humanity (and Canada) salute you.
Our eyes here at Txchnologist are usually firmly set to the horizon, scanning for what the future holds. Sometimes, though, we get a kick out of turning around and seeing what the past’s modern technology looked like and how people back then thought about the future.
Today, we bring you a few good finds from the vault that capture the future machines of the past. Click here to see a few more.
Stellar Archaeology Traces Milky Way’s History
Unfortunately, stars don’t have birth certificates. So, astronomers have a tough time figuring out their ages. Knowing a star’s age is critical for understanding how our Milky Way galaxy built itself up over billions of years from smaller galaxies. But Jason Kalirai of the Space Telescope Science Institute and The Johns Hopkins University’s Center for Astrophysical Sciences, both in Baltimore, Md., has found the next best thing to a star’s birth certificate.
Using a new technique, Kalirai probed the burned-out relics of Sun-like stars, called white dwarfs, in the inner region of our Milky Way galaxy’s halo. The halo is a spherical cloud of stars surrounding our galaxy’s disk. Those stars, his study reveals, are 11.5 billion years old, younger than the first generation of Milky Way stars. They formed more than 2 billion years after the birth of the universe 13.7 billion years ago. Previous age estimates, based on analyzing normal stars in the inner halo, ranged from 10 billion to 14 billion years. Kalirai’s study reinforces the emerging view that our galaxy’s halo is composed of a layer-cake structure that formed in stages over billions of years.
White dwarf stars have remarkable properties, yet they are very simple. These stripped cores of normal hydrogen-burning stars are about 1 million times denser than matter on Earth. This means that a tablespoon of material from a white dwarf’s surface would weigh as much as a school bus on Earth. White dwarfs also have no fuel to generate energy, and most of their atmospheres contain a single atom, hydrogen.
The second figure illustrates the spectral features of a white dwarf, in comparison to the Sun and a blue giant. The white dwarf spectrum is simple, containing only absorption lines from the hydrogen atom. But, unlike the same lines in the blue giant spectrum (a bloated star with a low density), the features in the white dwarf are broadened due to the intense pressure on the surface of the star (essentially, the energy levels of the atom are being perturbed). This broadening of the lines, as well as their depth, is directly related to the mass and temperature of the star. Unlike for most stars, astronomers can therefore reliably establish fundamental properties for white dwarfs from their spectra.
Like a thief in the night, the malaria parasite did its quick work and vanished inside a blood cell. But someone else was watching.
A cropped full size image, this is a large object as a planetary nebua.
Image is in visual spectrum and dominated by the red light emitted by ionized Hydrogen, H-alpha. Blueish hues are from ionized Oxygen, O-III. Some of the colors are shot simultaneously with H-a emission by using QHY8 color camera, Tokina AT-X 300mm f2.8 camera lens and Baader UHCs-filter. — J-P Metsävainio
The Sounds of a Pulsar
This pulsar lies near the center of the Vela supernova remnant, which is the debris of the explosion of a massive star about 10,000 years ago. The pulsar is the collapsed core of this star, rotating with a period of 89 milliseconds or about 11 times a second. Radiation is beamed out along the magnetic poles and pulses of radiation are received as the beam crosses the Earth, in the same manner as the beam from a lighthouse causes flashes. Being enormous cosmic flywheels with a tick attached, they make some of the best clocks known to mankind. These sounds directly correspond to the radio-waves emitted by the brightest pulsars in the sky as received by some of the largest radio telescopes in the world.
Well, this is
magnificentterrifying.
