A taste of WISE galaxies

By Phil Plait | May 26, 2011 7:00 am

The Wide-field Infrared Survey Explorer was turned off a few months ago, but the science it did lives on. NASA just released a gallery of nine spiral galaxy images taken by WISE, and they’re lovely:

[Click to galactinate.]

Several of my favorite big, grand design spirals are there, like M51, M81, and M83. Note that since WISE only sees infrared light, these are false color images; the colors used are blue for 3.4 micron IR light, cyan for 4.6 microns, green for 12 microns, and red for 22 microns. The reddest light a human eye can see is very roughly 0.75 microns, to give you a comparison. In the images, star-forming regions are yellowish and/or pink, dust (in the form of long-chain organic molecules called polycyclic aromatic hydrocarbons) is green, and old stars are blue.

While looking over the images, I actually recognized the name of the one in the lower right: IC 342 (here’s a full-res WISE shot of it). This is part of a small group of galaxies near our Milky Way that is heavily obscured by dust in our galaxy. Read More

CATEGORIZED UNDER: Astronomy, Pretty pictures

Orion's WISE head

By Phil Plait | April 15, 2011 7:00 am

Yesterday, the Universe just got a little bit more accessible: about 57% of the WISE mission’s infrared data of the sky has been released and can be searched online. Instructions on how to tap into that archive are available as well.

WISE mapped the entire sky in the infrared and found a treasure trove of fantastic objects (see Related Posts at the bottom of this post). As part of the news of this data release, NASA put up an image I hadn’t seen before, and it’s really amazing: the Lambda Orionis Nebula:

[Click to ennebulanate, but do it with care: the high-res version is a whopping 15,800 by 14,700 pixels and weighs in at 25 MB!]

It may look entirely alien, but you’ve probably seen this part of the sky before. See that blue star in the lower left? That’s Betelgeuse! Marking Orion’s shoulder, Betelgeuse is a red supergiant, destined one day to go supernova. It looks blue in this image because WISE sees in the infrared, and uses false colors. What’s colored blue in the image is actually light at a wavelength of 3.4 microns (the reddest light our eyes can see is about 0.7 microns). Cyan represents 4.6-microns, green is 12 microns, and red is 22 microns.

Betelgeuse puts out a lot of light in what we think of as red, but to WISE that’s actually a short wavelength, so the star looks blue in the picture. Green comes from organic long-chain molecules, while red is from warm dust. The star Bellatrix, Orion’s other shoulder, is the greenish star on the right. If you’re familiar with Orion, you’ll get the idea this picture covers a big region of the sky: hold your fist out arm’s length with your wrist line at Betelgeuse, and it will just about cover this image!

What you’re seeing is a thick, dense dust cloud. At the center is the star Lambda Orionis (the red one in the middle of the ring), a supergiant that, along with other massive stars, is warming up this vast cloud of material about 130 light years across.

Read More

CATEGORIZED UNDER: Astronomy, Pretty pictures, Top Post

S marks the spot

By Phil Plait | April 4, 2011 6:58 am

A few years back I was working on creating educational products for the NASA orbiting observatories Fermi and Swift. These look at super-violent high-energy objects like exploding stars and black holes gobbling down matter. All big galaxies have supermassive black holes in their cores, and some are sloppy eaters, spewing out vast amounts of energy as the material makes The Final Plunge.

I remember finding images of one such galaxy, simply called the Circinus Galaxy, and being baffled as to why I had never heard of it or could find so little info on it. It’s only 14 million light years away, close for a galaxy! Turns out, it’s heavily obscured to visible light telescopes because it happens to lie in the plane of our own galaxy, and we have to look through lots of thick dust to see it. That dims the light a lot! But infrared light can pierce through that dust, making this an interesting object at wavelengths invisible to the human eye, colors that happen to be the specialty of NASA’s WISE spacecraft. So when astronomers took a look, well, behold!

What an awesome picture! [Click to blackholenate.]

There’s a lot to see here. Read More

A giraffe's shocking neck

By Phil Plait | March 27, 2011 7:00 am

NASA’s Wide-field Infrared Survey Explorer took its last image of the sky in February, 2011. But while it was active it surveyed the entire sky several times in the far infrared, so its data archive is a vast treasure trove just waiting to be dug into (hmmm, I should try to squeeze another metaphor into there).

Anyway, lookee what the astronomers found:

Cooool. Literally! That’s dust surrounding the star Alpha Camelopardalis, what appears as a fairly non-descript star in a faint, non-descript constellation. At least, to the eye. When seen in the IR, you get this shocking view. Also literally.

Alpha Cam is a massive, luminous star: 50 times as hefty as our Sun, and blasting out perhaps a million times as much energy. But it’s far away (3000 light years, maybe, the distance is not well-known) and behind a lot of dust, dimming our view. It’s barreling through space at a pretty good clip, and emitting a wind of subatomic particles as it does. This wind expands, slams into the surrounding dust, and sculpting it into this giant bow shock formation.
Read More

CATEGORIZED UNDER: Astronomy, Cool stuff, Pretty pictures

WISE shuts its eye

By Phil Plait | March 24, 2011 7:00 am

One of my favorite space astronomy missions, WISE, has shut its eye for the last time.

This wasn’t unexpected, though! The Wide-field Infrared Survey Explorer was meant to be a short mission, mapping the sky in far-infrared light for a year or so. It needed coolant to chill its detectors, and that ran out last year. On February 1, 2011, it took this one, final image:

[Click to infrareddenate.]

That’s a shot of the constellation Perseus, which is along the plane of the Milky Way Galaxy and is thus littered with stars and dust. It’s very much like millions of other images WISE took in its time in space. Below are links to some of my favorite images from WISE, and you really should take a look. They are eerily beautiful, and tell us a lot about the Universe that our eyes cannot perceive.

My congratulations to all my friends at WISE on an amazingly successful mission!

Image Credit: NASA/JPL-Caltech/UCLA

Related posts:

Shocking star is shocking. Shocking, I say!
In galactic collisions, might makes right
A WISE view of a small neighbor
Warm dusty rings around a weird binary star (probably my favorite WISE pic!)
WISE finds the coolest stars. Literally.
The seven WISE sisters
A WISE flower blooms in space
The first spectacular views of the sky from WISE
WISE uncovers its first near-Earth asteroid!

CATEGORIZED UNDER: Astronomy, Pretty pictures

Shocking star is shocking. Shocking, I say!

By Phil Plait | January 24, 2011 4:48 pm

In a recent post, I said that science is at its best when it reveals both the inner and outer beauty of nature. I can’t think of a better example than this stunning picture of a runaway star from NASA’s Wide-field Infrared Survey Explorer, aka WISE:

OOOooo, pretty! Click to embiggen.

The star in question is the bright blue one in the center of the picture. Its name is Zeta Ophiuchi, and to the eye it’s a non-descript reddish star in the constellation of Ophiuchus (yes, the same one that recently found itself entangled in the zodiac embroglio). You wouldn’t look twice at it, but it hides some secrets. For one, it’s not red, it’s blue! It’s actually a supergiant, hot, blue star that’s probably 20 times the mass of the Sun. It looks reddish to the eye because there’s quite a bit of interstellar dust between us and it, and that tends to make light look redder (much like junk in the air makes a sunset look red). In fact, it’s only about 450 light years away; if there were no dust between us and it Zeta Oph would be one of the three or four brightest stars in the sky!

But it has another secret: it’s a runaway star. Read More

CATEGORIZED UNDER: Astronomy, Pretty pictures

In galactic collisions, might makes right

By Phil Plait | January 14, 2011 7:00 am

The Wide Field Infrared Survey Explorer (WISE) is an astronomy blogger’s gift that keeps on giving. Observing huge swaths of the sky in the infrared, it sends back the coolest images! Behold:

Yeah, click that to get the most cromulently embiggened 4000 x 4000 pixel version.

Those two galaxies are M82 (top) and M81 (bottom), and are both about 12 million light years away, relatively nearby as these things go. They are the two biggest galaxies in the M81 group, a collection of galaxies much like our own Local Group (dominated by our galaxy, the Milky Way, and Andromeda). M81 and M82 are almost certainly interacting with each, having had at least one pass sometime in the past, and may eventually merge in a billion years or so. Maybe less. Currently, they’re roughly 300,000 light years apart.

WISE sees them in the infrared, and in this picture blue represents the infrared wavelength of 3.4 microns, cyan is 4.6 microns, green is 12 microns, and red is 22 microns. For comparison, the reddest red your eyes can see is less than 1 micron, so these are well out into the IR.

Obviously, M81 looks very different than M82! M81 is a classic grand design spiral, roughly the same size or a bit smaller than the Milky Way. Most of the light you see comes from stars, which are bright at the shorter IR wavelengths.

M82, on the other hand, is a mess. Read More

CATEGORIZED UNDER: Astronomy, Pretty pictures

A WISE view of a small neighbor

By Phil Plait | January 4, 2011 7:00 am

What shall be the first astronomical object to grace this blog in 2011*? With a whole sky to choose from, why not use an old friend, but seen in a surprisingly new way? So I present to you the nearby Triangulum Galaxy, M33, as seen by the orbiting far-infrared telescope WISE:

Yeah, that’ll do! Click to galactinate.

M33 is familiar to pretty much any serious amateur astronomer north of the Equator. It’s not that far in the sky from its bigger buddy M31, the Andromeda Galaxy, and in fact isn’t terribly far in space either; Andromeda is about 2.5 million light years away, while M33 is about 3 million. M33 is a spiral galaxy as well, and one of the closest to us.

Andromeda is probably the most well-known galaxy in the sky. So why is M33 so less famous? Mostly because it’s smaller; Andromeda and the Milky Way are roughly the same size (so close, in fact, that astronomers have been arguing for decades over which is the beefier of the two, and the title has swapped back and forth many times), but M33 is only half our size. Also, it’s more face-on to us, spreading its light out, making it actually a somewhat tough object to see. I’ve seen it in binoculars from dark sites, but it’s only marginally brighter than the sky background.

In the WISE image, blue and cyan are from infrared light at 3.4 and 4.6 microns (roughly 5 and 6.5 times the reddest light your eye can see). That comes mostly from stars. Green and red are IR at 12 and 22 microns, much farther in the infrared, and comes from cooler material like interstellar dust, which is opaque to visible light.

Read More

CATEGORIZED UNDER: Astronomy, Pretty pictures

The Top 14 Astronomy Pictures of 2010

By Phil Plait | December 14, 2010 7:01 am

Use the thumbnails and arrows to browse the images, and click on the images themselves to go through to blog posts with more details and descriptions.


Warm dusty rings glow around a weird binary star

By Phil Plait | November 17, 2010 11:15 am

So I’m sitting at home catching up on email, and I get a note from my friend Whitney who does press and outreach for the NASA infrared observatories Spitzer and WISE. There’s a new image from WISE that might be of interest, she claims. OK, I think, clicking the link; WISE images are usually a bit odd — astronomical objects tend to look very different in the far infrared than what I’m used to –but even then, when the image came up on my browser, I was struck by a major dose of holy frakitis:


Wow. And holy frak!* What the heck is that thing?

2001_spacestationYou might be forgiven if your first thought is that it’s the space station from "2001: A Space Odyssey". But in fact it’s something a bit more distant: it’s NGC 1514, the gas and dust surrounding a dying star system about 700 light years away.

I am somewhat familiar with these objects, having studied one for my Master’s degree, and a similar object for my PhD. But planetary nebulae, as they’re called, are so diverse and weird that understanding one, or even several, doesn’t always help in understanding all of them. And this one is seriously freaky. Those rings, lovely as they are, turn out to be quite difficult to explain.

OK, here’s the very brief skinny: Read More

CATEGORIZED UNDER: Astronomy, Pretty pictures, Top Post

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