Brown Dwarf


BrownDwarfThis animation shows the coldest brown dwarf found to date. It also the fourth closest system to our Sun. WISE J085510.83-071442.5 is a very dim object that was noticed because of its rapid motion across the sky. It first showed up in two infrared images taken six months apart in 2010 by the Wide-field Infrared Survey Explorer, or WISE (the orange triangles). Two more images of the object were taken with the Spitzer Space Telescope in 2013 and 2014 (green triangles). Because the two satellites are in different orbits, their data could be used to calculate the distance to the brown dwarf: 7.2 light-years. The Spitzer data were used to show that the body appears to be roughly the same temperature as the Earth’s North Pole (-48 to -13 °C).

Image Credit: NASA

A Near Earth Asteroid


NearEarthAsteroidThe greenish-yellow dot in the upper left is the potentially hazardous near-Earth object 1998 KN3 moving past a cloud of dense gas and dust near the Orion nebula in the far, far background. NEOWISE, the asteroid-hunting portion of the Wide-field Infrared Survey Explorer, or WISE, mission, took this infrared picture. Because near-Earth asteroids are warmed by the Sun to roughly room temperature, they glow brightly at the infrared.

Infrared light from asteroids is used to measure their sizes. Combined with visible-light observations, that data can also measure the reflectivity of their surfaces. The WISE data reveal that this asteroid is about 1.1 km in diameter and reflects only about 7 percent of the visible light that falls on its surface. It is relatively dark.

In this image blue denotes shorter infrared wavelengths and red, longer. Hotter objects emit shorter-wavelength light; they appear blue. Stars with temperatures of thousands of degrees are blue. The coldest gas and dust are red. The asteroid appears greenish-yellow in the image because it is about room temperature—cooler than the stars, but warmer than the dust.

Image Credit: NASA

The Pleiades: Round 5


Pleiades_WISEThis false-color image shows the  Pleiades cluster of stars as seen through the eyes of WISE, the Wide-field Infrared Survey Explorer. It’s a mosaic of several hundred images from the more than one million WISE captured in its first survey of the entire sky in infrared light.

All four infrared detectors aboard WISE were used to make this mosaic. Blue and cyan represent infrared light at wavelengths of 3.4 and 4.6 µm, which is dominated by light from stars. Green and red represent light at 12 and 22 µm, which is mostly light from warm dust.

Image Credit: NASA

A Rare Luminous Blue Variable Star


The bright star to the right and above the center of the picture is cataloged as G79.29+0.46. It’s a massive luminous blue variable (LBV) star, one of only about 100 such stars in our galaxy. It’s very bright, but it can’t be seen from Earth in visible light because it’s extremely volatile and surrounded by a thick cloud of dust. The picture above is an infrared image put together by combining data from the Wide-Field Infrared Survey Explorer and the Spitzer Space Telescope. In this false color image the blue star appears green and the surrounding dust shell appears red.

Image Credit: NASA / Judy Schmidt (CC BY 2.0)

The Pleiades in IR


Pleiades_WISEThis false-color image shows the  Pleiades cluster of stars as seen through the eyes of WISE, the Wide-field Infrared Survey Explorer. It’s a mosaic of several hundred images from the more than one million WISE captured in its first survey of the entire sky in infrared light.

All four infrared detectors aboard WISE were used to make this mosaic. Blue and cyan represent infrared light at wavelengths of 3.4 and 4.6 µm, which is dominated by light from stars. Green and red represent light at 12 and 22 µm, which is mostly light from warm dust.

Image Credit: NASA

Brown Dwarfs


This is the first ultra-cool brown dwarf discovered by NASA's Wide-field Infrared Survey Explorer.A brown dwarf is an object that didn’t quite make it to stardom. It’s sub-stellar without enough mass to sustain hydrogen-1 fusion like a main sequence star. Brown dwarfs fill a niche between large planets and lightweight stars, ranging unto about 75X the mass of Jupiter. Brown dwarfs with mass greater 13X MJ may be able to fuse deuterium, and dwarf’s with mass above 75X MJ may be able to fuse lithium.

WISE 0458+6434 was the first ultra-cool brown dwarf discovered by the Wide-field Infrared Survey Explorer. It’s the green dot in the picture above which is from infrared data coded as green and blue depending on wavelength. WISE 0458+6434 is a binary system of two (A and B) ultracool brown dwarfs. The primary (A) has a mass about 15X Jupiter’s and a surface temperature of around 600 K or about 330 C. That’s roughly a tenth of the surface temperature of the Sun. Brown dwarfs have found with surface temperatures as low as -150 C.

Image Credit: NASA