Amazing photos of the universe captured by NASA’s galaxy finder   Leave a comment

A tribute to GALEX: Amazing photos of the universe captured by NASA’s galaxy finder

In just 10 E.arth years of operation, NASA’s Galactic Evolution Explorer, or GALEX, looked into more than 10 billion years of cosmic time. It saw hundreds of millions of galaxies, and it greatly expanded our understanding of the evolution of the universe. Thanks to this incredible breadth of work, it managed to give us some of the most stunning and important pictures of the cosmos despite being designed to see into areas of the spectrum that normally keep photos from being pleasing to the human eye. GALEX’s ultraviolet camera produced images and datasets that are striking all on their own, and others that could be combined with visible-spectrum images to show the shape of our universe in unprecedented detail, an accuracy no one observer could capture.

GALEX showed us galaxies in their infant, adolescent, adult, and elderly stages. It showed us some galaxies in mid-collision, and others on the brink of a natural death. Its ultraviolet eye also provided insight into fast-moving stars and black holes, letting scientists see a whole new slice of the light given off by incomprehensibly awesome events, many of which occurred before the formation of the Earth itself. It’s given insight into everything from galactic birth to the nature of dark energy.

Below are just a few images collected in tribute to the full lifetime of NASA’s GALEX space telescope.

GALEX 1

GALEX herself

GALEX sported a 50-centimeter primary aperture, in a Richey-Chretien f/6 configuration. The camera could see wavelengths between 135 and 280nm, well below the lower bound of visible light, which begins around 380nm. It’s 1.2-degree field of view was wide enough to let it see whole clusters of galaxies. The solar cells which dominate this picture could provide GALEX with almost 300 watts of power. This space telescope roamed the skies above earth from April 28, 2003 to June 28, 2013.

GALEX 2

Mira’s unbelievable tail

The star Mira was discovered more than 400 years ago, but it took an eye like GALEX to see its most stunning feature: a comet-like tail more than 13 light years in length (top half) It was formed over tens of thousands of years, and is totally invisible in the visible portion of the light spectrum (bottom half). Like a comet’s tail, this incredible, unique cosmological feature is now known to be made of up of the stripped constituents of the star itself.

GALEX 3

Crash of the titans

This photo, which is a composite of GALEX’s ultraviolet camera and preexisting visible information, shows a gargantuan galactic collision. The arms of the two galaxies are intertwined, as the main bodies are less than 60,000 light years apart. Information collected by GALEX on these two bodies has been studied for years and has provided insight into one of the universe’s most awesome events.

GALEX 4

The Cartwheel galaxy

This multi-wavelength composite image shows the Cartwheel galaxy through the eyes of GALEX, Hubble, the Spitzer Space Telescope, and the Chandra X-Ray Observatory. Only by combining the information collected by all of these could such a spectacular image be produced, one which condenses the full array of information from the galaxy into an image viewable by the human eye.

GALEX 5

A hello to arms

This image shows the previously hidden spiral arms of the galaxy NGC 4625, the higher of the two galaxies shown. Like Mira’s tail, these arms were all but invisible without the help of an ultraviolet camera like that carried by GALEX. The stars on these arms are new and burn very hot, primarily throwing out light in this area of the light spectrum. The lower galaxy is a nearby companion, and astronomers speculate that its lack of arms may be in some way involved in the development of arms in its sister.

GALEX Helix Nebula

The Helix Nebula

This isn’t a galaxy, but it is an example of what happens when a star approaches the end of its lifetime. Running low on fuel, it begins to expel gas outward in its evolution toward the small, intensely hot white dwarf stage. The Helix Nebula was only fully explored with the help of GALEX’s ultraviolet camera.

 

 

 

GALEX 7

The Milky Way’s big brother

NGC 6744 is a large galaxy which is actually very similar to the Milky Way. In fact, when you see photos of the “Milky Way,” very often you are looking at this galaxy as its representative — because taking a photo of the Milky Way is obviously rather difficult. At more than 175,000 light years in diameter, it dwarfs our own galaxy, however.

GALEX 8

A dwarf galaxy, hidden no longer

Set beside the giant barred spiral galaxy NGC 6872, this composite shot shows a previously invisible dwarf galaxy (circled). This tiny gem is only visible in the ultra-violet spectrum, as in all other wavelengths it is heartily drowned out by the light of its enormous neighbor. At more than 522,000 light years from tip-to-tip, it is one of the largest galaxies known in detail. Finding the dwarf galaxy so close could only have been done with a specialized space galaxy-finder.

GALEX 9

An erupting black hole

Unfortunately, the data collected by GALEX for this image was too abstract to be rendered directly. This computer-simulated image shows the trajectory of gas from a tidally shredded star falling into a black hole. This doomed body, and the glowing trail of mostly helium that it left in its wake, has been used by astronomers to help understand everything from black holes themselves to the nature of gravity and space-time.

It’s not quite over yet

GALEX has had a truly incredible run. Its operation was handed over to Caltech last year, and the university made good use of it during these final days. In fact, a good portion of the telescope’s work has yet to be computed and published, as it will be out of commission for a full year before its last findings can be reviewed. Set in a slightly degenerate orbit, GALEX will circle the Earth for more than 60 years to come, then eventually descend to burn up in the Earth’s atmosphere.

 

 

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