Category Archives: Space Telescope

Hubble’s View of NGC 6153


A nice (and timely) follow-up to a post last week talking a little about metallicity. This planetary nebula has no “common name” that I can find. Looks a bit like a Jellyfish to me.

Here’s ESA description:
This NASA/ESA Hubble Space Telescope image shows a planetary nebula named NGC 6153, located about 4,000 light-years away in the southern constellation of Scorpius (The Scorpion). The faint blue haze across the frame shows what remains of a star like the sun after it has depleted most of its fuel. When this happens, the outer layers of the star are ejected, and get excited and ionized by the energetic ultraviolet light emitted by the bright hot core of the star, forming the nebula.

Continue reading

Teenage Quasars

Quasars in Interacting Galaxies

It’s always nice when a Hubble release features a scientist at a home town school.  Bravo!

From Hubblesite:
Quasars are the light fantastic. They are the brightest beacons in the universe, blazing across space with the intrinsic brightness of one trillion suns. Yet the objects are not vast galaxies, but they appear as pinpoint sources in the biggest telescopes of today — hence the term “quasar” for quasi-stellar object. Discovered in the 1960s, it took more than two decades of research to come to the conclusion that quasars are produced by the gusher of energy coming from over-fed supermassive black holes inside the cores of very distant galaxies. And, most quasars bloomed into a brief existence 12 billion years ago.

The big question has been, why? What was happening in the universe 12 billion years ago? The universe was smaller and so crowded that galaxies collided with each other much more frequently than today. Astronomers using Hubble’s near-infrared vision tested this hypothesis by looking at dusty quasars where their glow was suppressed by dust, allowing a view of the quasar’s surroundings. Hubble’s sharp vision revealed chaotic collisions between galaxies that gave birth to quasars by fueling a supermassive central black hole.

“The Hubble observations are definitely telling us that the peak of quasar activity in the early universe is driven by galaxies colliding and then merging together,” said Eilat Glikman of Middlebury College in Vermont. “We are seeing the quasars in their teenage years, when they are growing quickly and all messed up.”

Read the full story.

The Star Called Nasty 1


This is an artist concept of kind of a weird acting star (Artist rendition: NASA, ESA, and G. Bacon (STScI)). Wolf-Rayet stars are massive stars. We even know of one WR star that has the mass of around 265 of our Sun located in the Large Magellanic Cloud about 165,000 light-years from us in the R136 super cluster called R136a1. In our own Milky Way there are about 500 WR stars.  That’s so big it’s almost hard to imagine.

Then there is Nasty 1, this intro from Hubblesite (link goes to full story):

Astronomers have spent decades trying to determine the oddball behavior of an aging star nicknamed “Nasty 1” residing in our Milky Way galaxy. Nasty 1 was identified as a Wolf-Rayet star, a rapidly evolving star that is much more massive than our sun. The star loses its hydrogen-filled outer layers quickly, exposing its super-hot and extremely bright helium-burning core.

But Nasty 1 doesn’t look like a typical Wolf-Rayet star. Astronomers using NASA’s Hubble Space Telescope had expected to see a bipolar outflow of twin lobes of gas from the star, perhaps similar to those emanating from the massive star Eta Carinae. The astronomers were surprised, however, to find a pancake-shaped disk of gas encircling the star. The vast disk is nearly 1,000 times the diameter of our solar system. It may have formed from the interaction between Nasty 1 and an unseen companion star. The star may represent a brief transitory stage in the evolution of extremely massive stars. Nasty 1’s nickname was derived from its catalog name of NaSt1.

The Boomerang Nebula


This image is the Boomerang Nebula, a product of ALMA and Hubble. The Boomerang is 5,000 light-years away in the constellation Centaurus. Click the image above to see the Hubble image without the ALMA data, you will also see why it also has the name of the Bow Tie Nebula.

The Boomerang is a protoplanetary nebula, a confusing term because it does not mean it is forming planets, it’s between the (asymptotic) giant phase and the planetary nebula phase. The cool thing about the Boomerang is not just cool it is cold. It is the coldest place we know of, 1 degree Kelvin and that’s -272.15 C / -457.87 F, the atoms are just barely moving!

I also can’t help thinking I saw an episode of Star Trek with a creature that looks a lot like the ALMA addition.

Image: Bill Saxton; NRAO/AUI/NSF; NASA/Hubble; Raghvendra Sahai

Hubble Update to NGC 6240


Here is an updated Hubble image of the galactic merger NGC 6240 (image description below) from an image in 2008. The image was taken with the Wide Field Camera 3 and Advanced Camera for Surveys which gives us a more detailed look at the center of the galaxies than in 2008. Click the image above to see the difference.

When I say galactic merger I don’t want to imply this merger is complete – far from it. What isn’t seen here are two black holes at the center of the merger only 3000 light-years apart and that is close enough for their fate to be set. The two black holes are feeling their mutual gravitational attraction and are slowly spiraling towards each other and will eventually merge into a single black hole.

We do have X-ray evidence of the two black holes in this image from the Chandra X-ray Observatory taken in 2002.

NGC 6240 is located 400 million light-years away in the constellation Ophiuchus, that is so far away, who knows perhaps the merger has already taken place, the cosmic look back time in action.

A side note: You would think there would be stars colliding in such mergers, but this is not the case. The distances between stars is so large such collisions are unlikely at least in any widespread way.

From Hubble (and you can get desktop versions of the image at the link):
Not all galaxies are neatly shaped, as this new NASA/ESA Hubble Space Telescope image of NGC 6240 clearly demonstrates. Hubble previously released an image of this galaxy back in 2008, but the knotted region, shown here in a pinky-red hue at the centre of the galaxies, was only revealed in these new observations from Hubble’s Wide Field Camera 3 and Advanced Camera for Surveys.

NGC 6240 lies 400 million light-years away in the constellation of Ophiuchus (The Serpent Holder). This galaxy has an elongated shape with branching wisps, loops and tails. This mess of gas, dust and stars bears more than a passing resemblance to a butterfly and, though perhaps less conventionally beautiful, a lobster.

This bizarrely-shaped galaxy did not begin its life looking like this; its distorted appearance is a result of a galactic merger that occurred when two galaxies drifted too close to one another. This merger sparked bursts of new star formation and triggered many hot young stars to explode as supernovae. A new supernova was discovered in this galaxy in 2013, named SN 2013dc. It is not visible in this image, but its location is indicated here.

At the centre of NGC 6240 an even more interesting phenomenon is taking place. When the two galaxies came together, their central black holes did so too. There are two supermassive black holes within this jumble, spiralling closer and closer to one another. They are currently only some 3000 light-years apart, incredibly close given that the galaxy itself spans 300 000 light-years. This proximity secures their fate as they are now too close to escape each other and will soon form a single immense black hole.

25 Years of Hubble

NASA Unveils Celestial Fireworks as Official Hubble 25th Anniversary Image

Happy Anniversary Hubble! Hubble was launched 25 years ago today on 24 April 1990 aboard the Shuttle Discovery on mission STS-31.

The Hubble was deployed on 25 April 1990 and immediately a problem with the optics was noticed and it would take a couple of years to get a correction in place. Once the corrective optics, kind of like “eye-glasses” for the telescope were flown up in December 1993 aboard the Shuttle Endeavour along with a few other upgrades and the repairs were made, the images were stunning.

Hubble has be serviced a few times since and continues to advance our knowledge and will for many more years with any luck at all.

About the image from Hubblesite:

NASA and ESA are celebrating the Hubble Space Telescope’s silver anniversary of 25 years in space by unveiling some of nature’s own fireworks — a giant cluster of about 3,000 stars called Westerlund 2. The cluster resides inside a vibrant stellar breeding ground known as Gum 29, located 20,000 light-years away in the constellation Carina. The comparatively young, 2-million-year-old star cluster contains some of our galaxy’s hottest, brightest, and most massive stars. The largest stars are unleashing a torrent of ultraviolet light and hurricane-force winds that etch away the enveloping hydrogen gas cloud. This creates a fantasy celestial landscape of pillars, ridges, and valleys.

Credit: NASA, ESA, the Hubble Heritage Team (STScI/AURA), A. Nota (ESA/STScI), and the Westerlund 2 Science Team

Hubble and NGC 2865


Yes the galaxy NGC 2865 is a bit different, an elliptical with lots of young stars is not what we would first think of in an elliptical galaxy. I’ll let ESA/NASA explain, but be sure to click the image and get the larger version. The number of galaxies much further away is amazing and one of the hallmarks of Hubble images.

This NASA/ESA Hubble Space Telescope image shows an elliptical galaxy called NGC 2865. It lies just over 100 million light-years away from us in the constellation of Hydra — The Sea Serpent — and was discovered in 1835 by astronomer John Herschel.

Elliptical galaxies are usually filled with old, dying stars. NGC 2865, however, is relatively youthful and dynamic, with a rapidly rotating disk full of young stars and metal-rich gas. For an elliptical galaxy it contains an unusually high number of young stars — suggesting that a galaxy-wide starburst took place about one billion years ago.

The starburst itself was induced by a merger between a spiral galaxy, similar to our galaxy, the Milky Way, and an elliptical galaxy some three times more massive — the progenitor galaxy of NGC 2865. The new gas from the spiral galaxy revitalized the dying population of old stars in the elliptical galaxy, and several new generations of stars were born.

The faint halo surrounding the galaxy, visible in this image, is also a result of this merger. It consists of cold gas that was ripped away from the spiral galaxy during the merging process. The gas now forms an almost closed shell around its host galaxy.

European Space Agency
Credit: ESA/Hubble & NASA
Acknowledgement: Judy Schmidt

GK Persied

A colloboration of Chandra, Hubble, and VLA showing GK Persei.  Image Credit: NASA/CXC/RIKEN/D.Takei et al
A colloboration of Chandra, Hubble, and VLA showing GK Persei. Image Credit: NASA/CXC/RIKEN/D.Takei et al

Astronomers studied the famous 1901 nova with the Chandra X-ray Observatory (blue color) in February 2000 and again November 2013 with additional data from Hubble (yellow color), and the Very Large Array (pink). The 13-span provided some interesting data and new questions.

First a little backgound. In 1901 GK Persei suddenly became one of the brightest objects in the sky. It was a classic nova, one where material was collected by a white dwarf star from a companion star builds up to a point when nuclear fusion reactions can occur and the outer layers of the white dwarf are blown away by the explosion. The results of the explosion can be seen for weeks and sometimes years especially if we use world class observatories. Think of these explosions as mini-supernovae. Supernova are responsible for making the heavy elements that make planets, moons and even us. Studying these smaller explosions gives us clues to dynamics of larger one.

The debris from the nova has expanded of a speed around 1,126,510 kmh / 700,000 mph. That means in the 13 years between observations the blast wave moved over 144 billion km / 90 billion miles.

The luminosity of the Persei remnant has decreased by about 40 percent, that’s pretty reasonable but the temperature of the explosion has remained constant at about a million degrees Celsius. The temperature should have dropped, suggesting the blast wave is expanding into a region of lower density.

The optical data show clumps of material ejected in the explosion as expected, there is a point souce in the lower left of the image, the nature of which is unknown.

A more indepth explanation of the image can be found here.