oplik:

Pics I’ve taken at the observatory. A 4 second exposure on a 14” reflector (yeah we have a really old TV). Click pics for descriptions if you please

spaceplasma:

Kirlian photography

Kirlian photography is a collection of photographic techniques used to capture the phenomenon of electrical coronal discharges. It is named after Semyon Kirlian, who, in 1939 accidentally discovered that if an object on a photographic plate is connected to a high-voltage source, an image is produced on the photographic plate.

Kirlian photography is a technique for creating contact print photographs using high voltage. The process entails placing sheet photographic film on top of a metal discharge plate. The object to be photographed is then placed directly on top of the film. High voltage is momentarily applied to the metal plate, thus creating an exposure. The corona discharge between the object and the high voltage plate is captured by the film. The developed film results in a Kirlian photograph of the object.

Color photographic film is calibrated to faithfully produce colors when exposed to normal light. Corona discharges can interact with minute variations in the different layers of dye used in the film, resulting in a wide variety of colors depending on the local intensity of the discharge. Film and digital imaging techniques also record light produced by photons emitted during corona discharge (see Mechanism of corona discharge).

Photographs of inanimate objects such as a coins, keys and leaves can be made more effectively by grounding the object to the earth, a cold water pipe or to the opposite (polarity) side of the high voltage source. Grounding the object creates a stronger corona discharge.

Kirlian photography does not require the use of a camera or a lens because it is a contact print process. It is possible to use a transparent electrode in place of the high voltage discharge plate, allowing one to capture the resulting corona discharge with a standard camera or a video camera.

futurist-foresight:

The problem of space junk or space debris is increasing. And with out greater dependence on satellites is a grave problem.

spaceplasma:

There’s a lot of debris floating around in space, and researchers at the Lawrence Livermore National Lab are using supercomputers, optical sensors and other technology to track even small objects that could damage important satellites.

John Henderson, a space scientist at LLNL, explains:

“Everybody uses GPS to get from here to there. We have satellite television, we have weather reports, farmers use satellite data for monitoring crops. If you have a piece of satellite debris whacking into a satellite, in the worst case you now lose that capability.  In February of 2009, that actually happened where there was an Iridium communications satellite that collided with a dead Russian Kosmos satellite and so that basically took out a $100 million dollar satellite.

There’s somewhere between 100,000 to 200,000 pieces of debris that we would like to be tracking. And so the supercomputing capabilities that we have here at Livermore are one way to keep track of that.”

so-do-it:

oH MY GOD YOU GUYS

stellar-indulgence:

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.

Credit: NASA, ESA, and A. Feild and J. Kalirai (STScI)