Posts tagged "Spitzer Space Telescope"
-
Notes: 35 / 3 months ago from unknownskywalker
Not-So-Bright Bulbs
This artist’s concept shows the dimmest star-like bodies currently known — twin brown dwarfs referred to as 2M 0939. The twins, which are about the same size, are drawn as if viewed from one side.
Brown dwarfs are neither planets nor stars. They form like stars out of collapsing clouds of gas and dust, but they don’t have enough mass to ignite nuclear burning in their cores and become full-blown stars. They are similar to Jupiter in that they are cool balls of gas, but they are warmer and heavier.
The universe is littered with these cosmic misfits, but because they are so dim, they are hard to find. Spitzer Space Telescope’s infrared eyes can detect the minute glow of these cool objects. Both of the brown dwarfs making up 2M 0939 are the dimmest known, and their atmospheres are also among the coolest known for any brown dwarf (565-635 Kelvin or 560-680 °F).
The term “brown dwarf” comes from the fact that these objects change color over time, and therefore do not have a definitive color. The 2M 0939 brown dwarfs, if we could see them directly with out eyes, would glow a very dark magenta color, due to their cool temperatures and the presence of water, methane and ammonia gases in their atmospheres.
-
Notes: 62 / 4 months ago from unknownskywalker
Pulverized Planet Dust May Lie Around Double Stars
Tight double-star systems might not be the best places for life to spring up, according to a new study using data from NASA’s Spitzer Space Telescope. The infrared observatory spotted a surprisingly large amount of dust around three mature, close-orbiting star pairs. Where did the dust come from? Astronomers say it might be the aftermath of tremendous planetary collisions.
The particular class of double stars in the study, RS Canum Venaticorums (RS CVns for short), are separated by only about two million miles, or two percent of the distance between Earth and our sun. The stellar pairs orbit around each other every few days, with one face on each star perpetually locked and pointed toward the other.
The close-knit stars are similar to the sun in size and are probably about a billion to a few billion years old — roughly the age of our sun when life first evolved on Earth. But these stars spin much faster, and, as a result, have powerful magnetic fields, and giant, dark spots. The magnetic activity drives strong stellar winds that slow the stars down, pulling the twirling duos closer over time. And this is where the planetary chaos may begin.
As the stars cozy up to each other, their gravitational influences change, and this could cause disturbances to planetary bodies orbiting around both stars. Comets and any planets that may exist in the systems would start jostling about and banging into each other, sometimes in powerful collisions.
Above: (1) This artist’s concept illustrates an imminent planetary collision around a pair of double stars. (2) This artist’s concept illustrates a tight pair of stars and a surrounding disk of dust — most likely the shattered remains of planetary smashups.
-
Notes: 90 / 7 months ago from unknownskywalker
Swirling Landscape of Stars
This swirling landscape of stars is known as the North America Nebula. In visible light, the region resembles North America, but in this image infrared view from NASA’s Spitzer Space Telescope, the continent disappears.
Where did the continent go? The reason you don’t see it in Spitzer’s view has to do, in part, with the fact that infrared light can penetrate dust whereas visible light cannot. Dusty, dark clouds in the visible image become transparent in Spitzer’s view. In addition, Spitzer’s infrared detectors pick up the glow of dusty cocoons enveloping baby stars.
Clusters of young stars (about one million years old) can be found throughout the image. Some areas of this nebula are still very thick with dust and appear dark even in Spitzer’s view.
Following
