About 7,500 years ago, a star went supernova. The Crab Nebula is the wreckage of that supernova whose explosion was seen on Earth in the year AD 1054. The expanding cloud of gas is located 6,500 light-years away in the constellation Taurus. This false color composite of three ultraviolet images taken by the UV Optical Telescope carried on the Swift satellite highlights the hot gas in the supernova remnant. The image is constructed from exposures using these filters centered at 260 nm (red), at 225 nM (green), and centered at 193 nm (blue). (Click the image to embiggen it.)
Yesterday, we took a look at the Andromeda Galaxy (aka M31) in Infrared and radio wavelengths. Today, we view it in the ultraviolet end of the spectrum. It took 11 images from the Galaxy Evolution Explorer (GALEX) satellite’s telescope to produce this UV portrait of the galaxy. While its spiral arms stand out in visible light images, they look like rings in UV because the image is dominated by light from hot, young, massive stars. The rings of intense star formation have been interpreted as evidence Andromeda collided with its smaller neighboring elliptical galaxy M32 more than 200 million years ago.
On 29 April, 2015, three satellite observatories—NuSTAR, Hinode, and Solar Dynamics Observatory—all stared at our Sun. This image merges data from Nuclear Spectroscopic Telescope Array, or NuSTAR (high-energy x-rays shown in blue), Japan’s Hinode spacecraft (low-energy x-rays in green), and SDO (extreme UV in yellow and red). The blue-white NuSTAR data pinpoint the most energetic areas.
This is the first image of Saturn’s aurora that was taken by the Hubble Space Telescope in 1997 when Saturn was 1.3 billion km from Earth. Saturn’s auroral displays are caused by an energetic wind of charged particles from the Sun that sweeps over the planet. Unlike the Earth’s, Saturn’s aurora is only seen in ultraviolet light. Because the UV doesn’t penetrate our atmosphere, Saturn’s aurora can only be observed from space.
This animation shows a series of views of the Sun captured by Extreme Ultraviolet Imager on the Solar Orbiter on 30 May. They show the Sun’s appearance at a wavelength of 17 nanometers in the extreme ultraviolet region of the electromagnetic spectrum. Images at this wavelength allow examination of the Sun’s upper atmosphere and the corona, regions with temperatures of more than 1,000,000 C.
Image Credits: ESA, NASA, CSL, IAS, MPS, PMOD/WRC, ROB, UCL/MSSL