Stars Archives

February 22, 2013December 23, 2015 by Jason Major

Bright Jets Blast Out from a Newborn Star

A young star is spotted firing jets of material out into space (ESA/Hubble & NASA. Acknowledgement: Gilles Chapdelaine)

Like very young humans, very young stars also tend to make a big mess out of the stuff around them — except in the case of stars it’s not crayon on the walls and Legos on the floor (ouch!) but rather huge blasts of superheated material that are launched from their poles far out into space.

The image above, acquired by the Hubble Space Telescope, shows one of these young stars caught in the act.

HL Tau is a relatively newborn star, formed “only” within the past several hundred thousand years. During that time it has scooped up vast amounts of gas and dust from the area around itself, forming a disc of hot, accelerated material that surrounds it. While most of this material eventually falls into the star, increasing its mass, some of it gets caught up in the star’s complex, rotating magnetic fields and is thrown out into space as high-speed jets.

As these jets plow thorough surrounding interstellar space they ram into nearby clouds of molecular gas, ionizing the material within them and causing them to glow brightly. These “shocks” are known as Herbig-Haro objects, after researchers George Herbig and Guillermo Haro who each discovered them independently in the early 1950s.

Detail of HH 151's jet — Detail of HH 151’s jet

In this Hubble image HH 151 is visible as a multiple-lobed cone of material fired away from HL Tau, with the leftover glows from previous outbursts dimly illuminating the rest of the scene.

The material within these jets can reach speeds of several hundred to a thousand kilometers a second. They can last anywhere from a few years to a few thousand years.

HH 151 is embedded within the larger star-forming region LDN 1551, located about 450 light-years away in the constellation Taurus. LDN 1551 is a stellar nursery full of dust, dark nebulae, newborn stars… and Herbig-Haro objects like HH 151.

(Hey, if baby stars are going to make a mess at least they can do it in the nursery.)

February 10, 2013December 23, 2015 by Jason Major

A Cosmic Snake for Chinese New Year

Barnard 72 - the "Snake Nebula" (Wikisky.org)

Gong Hey Fat Choy! Today marks the beginning of the Chinese New Year and what better way to celebrate the Year of the Black Snake than with a look at an enormous shadowy cosmic serpent, the Snake Nebula!

Also known as Barnard 72, the Snake Nebula is a meandering lane of dark dust located about 650 light-years away in the constellation Ophiuchus. Several light-years long, its opaque dust blocks our view of stars within the central bulge of the galaxy… but also reveals its presence since that region of the sky is literally filled with stars.

The Snake Nebula is part of the larger Dark Horse Nebula.

The bright star seen in the image just below the snake’s middle (looks like it may have just had dinner!) is HD 157398, a giant orange star 538 light-years from Earth. Here it shines brightly, but in the sky its visible magnitude is 6.67 — just a bit dimmer than what can be seen with the naked eye under the darkest skies.

Image via Wikisky.org.

February 6, 2013December 23, 2015 by Jason Major

Earthlike Exoplanets Are All Around Us

Artist's impression of a Jupiter-sized exoplanet orbiting an M-dwarf star

Artist’s impression of a rocky planet orbiting a red dwarf. Credit: David A. Aguilar (CfA)

We may literally be surrounded by potentially habitable exoplanets, according to new research by a team from the Harvard-Smithsonian Center for Astrophysics.

Using data gathered by NASA’s exoplanet-hunting Kepler spacecraft, the CfA researchers discovered that many red dwarf stars harbor planets, and some of those planets are rocky, Earth-sized worlds. Considering that red dwarfs, albeit optically dim, are the most abundant type of stars in our galaxy, this means that even a small percentage of them being host to Earthlike exoplanets puts the total number of potentially habitable worlds very high — and some of them could be right next door.

“We thought we would have to search vast distances to find an Earth-like planet,” said CfA astronomer and the paper’s lead author Courtney Dressing. “Now we realize another Earth is probably in our own backyard, waiting to be spotted.”

And our own backyard, in cosmic terms, could mean a mere 13 light-years away.

Our solar system is surrounded by red dwarfs. You can’t see them in the night sky because they are much too dim — less than a thousandth the brightness of the Sun. But they make up 75% of the stars in the local neighborhood, and based on the Kepler data the CfA team estimates that 6% of those red dwarfs likely have an Earth-sized planet in orbit around them.

And with at least 75 billion red dwarfs scattered across the galaxy… well, you do the math.*

“We now know the rate of occurrence of habitable planets around the most common stars in our galaxy,” said co-author David Charbonneau (CfA). “That rate implies that it will be significantly easier to search for life beyond the solar system than we previously thought.”

A visualization of the “unseen” red dwarfs in the night sky. Credit: D. Aguilar & C. Pulliam (CfA) See original here.

The conditions on a planet orbiting a red dwarf wouldn’t be exactly like Earth, of course. The planet would have to orbit rather closely to its star to be within its habitable zone, and would have to have a reasonably thick atmosphere to regulate heat and protect it from stellar outbursts. But one benefit to orbiting a red dwarf is that they have very long life spans — potentially longer than the current age of the Universe! So a habitable world around a red dwarf would literally have billions of years for life to evolve, thrive and develop on it.

“We might find an Earth that’s 10 billion years old,” Charbonneau said.

The team’s findings were presented today, Feb. 6, by Dressing during a press conference at the Harvard-Smithsonian Center for Astrophysics in Cambridge, MA. The results will be published in The Astrophysical Journal. (Added 2/7/13: here’s the video of the press conference.)

CfA astronomers identified 95 planetary candidates circling red dwarf stars. Of those, three orbit within the habitable zone (marked in green) – the distance at which they should be warm enough to host liquid water on the surface. Those three planetary candidates (marked with blue dots) are 0.9, 1.4, and 1.7 times the size of Earth. Credit: C. Dressing (CfA)

We Are Made of Stardust

This brief quote by the late Carl Sagan is wonderfully illustrated in the beautiful and poignant short film “Stardust,” directed by Mischa Rozema of Amsterdam-based media company PostPanic. Using actual images from space exploration as well as CGI modeling, Stardust reminds us that everything we and the world around us are made of was created inside stars… and that, one day, our home star will once again free all that “stuff” back out into the Universe.

The film was made in memory of talented Dutch designer Arjan Groot, who died of cancer in July 2011 at the age of 39.

“I wanted to show the universe as a beautiful but also destructive place. It’s somewhere we all have to find our place within. As a director, making Stardust was a very personal experience but it’s not intended to be a personal film and I would want people to attach their own meanings to the film so that they can also find comfort based on their own histories and lives.”
– Mischa Rozema, director

A truly stunning tribute.

See more about this on PostPanic’s Vimeo page. (Credits after the jump.)

Credits:
A PostPanic Production
Written & directed by Mischa Rozema
Produced by Jules Tervoort
VFX Supervisor: Ivor Goldberg
Associate VFX Supervisor: Chris Staves
Senior digital artists: Matthijs Joor, Jeroen Aerts
Digital artists: Marti Pujol, Silke Finger, Mariusz Kolodziejczak, Dieuwer Feldbrugge, Cara To, Jurriën Boogert
Camera & edit: Mischa Rozema
Production: Ania Markham, Annejes van Liempd
Audio by Pivot Audio , Guy Amitai
Featuring “Helio” by Ruben Samama
Copyright 2013 Post Panic BV, All rights reserved

In the grand scheme of the universe, nothing is ever wasted and it finds comfort in us all essentially being Stardust ourselves. Voyager represents the memories of our loved ones and lives that will never disappear.

January 23, 2013December 23, 2015 by Fraser Cain

Detailed View of Betelgeuse, on a Collision Course with a Nearby Wall of Dust

A photograph of the red supergiant Betelgeuse interacting with a mysterious dusty wall. Image credit: Herschel/ESA

Betelgeuse is one of my favorite objects to look at, partly because of its pure red color, and mostly because my imagination fills in the rest. That bright red star, the shoulder of Orion is a supergiant, with dozens of times the mass of the Sun, and ready to detonate as a supernova any day now (any day within the next few million years).

But look at Betelgeuse with a really powerful telescope, like the European Space Agency’s Herschel telescope, and you’ll see something like this: the red supergiant Betelgeuse in all its glory, smashing its ferocious solar winds into its environment.

In this photograph, just released from the European Space Agency, you can see the powerful solar winds creating a bow shock around the star as it ploughs through the interstellar medium at a speed of 30 km/s. Closer into the star there are asymmetric structures, where the star shed material in fits and starts into its surroundings, like convective bubbles randomly popping to the top of a pot of boiling water.

It’s the interaction of this supergiant star and its surroundings that astronomers were attempting to unravel with their research, in a paper titled: The enigmatic nature of the circumstellar envelope and bow shock surrounding Betelgeuse as revealed by Herschel. Researchers from several European universities combined data from Herschel, the GALEX space observatory, WISE, and even radio wavelengths to study Betelgeuse and its environment. They studied the star, the bow shock, and the asymmetric clumps of material around it.

Over on the left-hand side of the photograph is a mysterious dusty wall structure that Betelgeuse is heading straight for. Because this dusty wall doesn’t curve, like the bow shock around Betelgeuse, astronomers don’t think it was caused by the star itself. According to the researchers:

The linear bar might be the edge of an interstellar cloud illuminated by Betelgeuse or a linear filament whose a possible origin is linked to the Galactic magnetic field. Since no curvature is present in the bar, we believe that the bar is not directly linked to a previous blue supergiant wind

Betelgeuse is, however, responsible for illuminating this structure, like a flashlight illuminating a nearby fog bank. And according the astronomer’s calculations, the star’s bow shock will collide with that wall in a mere 5,000 years, with the star itself following suit 12,500 years later.

Original Source: ESA News Release

January 11, 2013April 26, 2016 by Jason Major

So. Many. Stars…

Infrared image of globular cluster 47 Tucanae (NGC 104) captured by ESO’s VISTA telescope.

“My god, it’s full of stars!” said Dave Bowman in the movie 2010 as he entered the monolith, and one could imagine that the breathtaking view before him looked something like this.

Except this isn’t science fiction, it’s reality — this is an image of globular cluster 47 Tucanae taken by the European Southern Observatory’s VISTA telescope at the Paranal Observatory in Chile. It reveals in stunning detail a brilliant collection of literally millions of stars, orbiting our Milky Way galaxy at a distance of 15,000 light-years.

The full image can be seen below.

47 Tucanae (also known as NGC 104) is located in the southern constellation Tucana. It’s bright enough to be seen without a telescope and, even though it’s very far away for a naked-eye object, covers an area about the size of the full Moon.

In reality the cluster is 124 light-years across.

Although globular clusters like 47 Tucanae are chock-full of stars — many of them very old, even as stars go — they are noticeably lacking in clouds of gas and dust. It’s thought that all the gaseous material has long since condensed to form stars, or else has been blown away by radiation and outbursts from the cluster’s exotic inhabitants.

At the heart of 47 Tucanae lie many curious objects like powerful x-ray sources, rapidly-spinning pulsars, “vampire” stars that feed on their neighbors, and strange blue stragglers — old stars that somehow manage to stay looking young. (You could say that a globular cluster is the cosmic version of a trashy reality show set in Beverly Hills.)

Red giants can be seen surrounding the central part of the cluster, old bloated stars that are running out of fuel, their outer layers expanding.

The background stars in the image are part of the Small Magellanic Cloud, which was in the distance behind 47 Tucanae when this image was taken.

VISTA is the world’s largest telescope dedicated to mapping the sky in near-infrared wavelengths. Located at ESO’s Paranal Observatory in Chile, VISTA is revealing new views of the southern sky. Read more about the VISTA survey here.

Image credit: ESO/M.-R. Cioni/VISTA Magellanic Cloud survey. Acknowledgment: Cambridge Astronomical Survey Unit

January 9, 2013December 23, 2015 by Jason Major

Clouds of Sand and Iron Swirl in a Failed Star’s Extreme Atmosphere

This artist's conception illustrates the brown dwarf named 2MASSJ22282889-431026. NASA's Hubble and Spitzer space telescopes observed the object to learn more about its turbulent atmosphere. Brown dwarfs are more massive and hotter than planets but lack the mass required to become sizzling stars. Their atmospheres can be similar to the giant planet Jupiter's. Spitzer and Hubble simultaneously observed the object as it rotated every 1.4 hours. The results suggest wind-driven, planet-size clouds. Image credit: — This artist's conception illustrates what a "hot jupiter" might look like.

Artist’s concept of brown dwarf 2MASSJ22282889-431026 (NASA/JPL-Caltech)

The complex weather patterns within the atmosphere of a rapidly-rotating brown dwarf have been mapped in the highest detail ever by researchers using the infrared abilities of NASA’s Spitzer and Hubble space telescopes… talk about solar wind!

Sometimes referred to as failed stars, brown dwarfs form from condensing gas and dust like regular stars but never manage to gather enough mass to ignite full-on hydrogen fusion in their cores. As a result they more resemble enormous Jupiter-like planets, radiating low levels of heat while possessing bands of wind-driven eddies in their upper atmospheric layers.

Although brown dwarfs are by their nature very dim, and thus difficult to observe in visible wavelengths of light, their heat can be detected by Hubble and the Spitzer Space Telescope — both of which can “see” just fine in near- and far-infrared, respectively.

Led by researchers from the University of Arizona, a team of astronomers used these orbiting observatories on July 7, 2011 to measure the light curves from a brown dwarf named 2MASSJ22282889-431026 (2M2228 for short.) What they found was that while 2M2228 exhibited periodic brightening in both near- and far-infrared over the course of its speedy 1.43-hour rotation, the amount and rate of brightening varied between the different wavelengths detected by the two telescopes.

“With Hubble and Spitzer, we were able to look at different atmospheric layers of a brown dwarf, similar to the way doctors use medical imaging techniques to study the different tissues in your body.”

– Daniel Apai, principal investigator, University of Arizona

This unexpected variance — or phase shift — most likely indicates different layers of cloud material and wind velocities surrounding 2M2228, swirling around the dwarf star in very much the same way as the stormy cloud bands seen on Jupiter or Saturn.

But while the clouds on Jupiter are made of gases like ammonia and methane, the clouds of 2M2228 are made of much more unusual stuff.

“Unlike the water clouds of Earth or the ammonia clouds of Jupiter, clouds on brown dwarfs are composed of hot grains of sand, liquid drops of iron, and other exotic compounds,” said Mark Marley, a research scientist at NASA’s Ames Research Center and co-author of the paper. “So this large atmospheric disturbance found by Spitzer and Hubble gives a new meaning to the concept of extreme weather.”

While it might seem strange to think about weather on a star, remember that brown dwarfs are much more gas planet-like than “real” stars. Although the temperatures of 1,100–1,600 ºF (600–700 ºC) found on 2M2228 might sound searingly hot, it’s downright chilly compared to even regular stars like our Sun, which has an average temperature of nearly 10,000 ºF (5,600 ºC). Different materials gather at varying layers of its atmosphere, depending on temperature and pressure, and can be penetrated by different wavelengths of infrared light — just like gas giant planets.

“What we see here is evidence for massive, organized cloud systems, perhaps akin to giant versions of the Great Red Spot on Jupiter,” said Adam Showman, a theorist at the University of Arizona involved in the research. “These out-of-sync light variations provide a fingerprint of how the brown dwarf’s weather systems stack up vertically. The data suggest regions on the brown dwarf where the weather is cloudy and rich in silicate vapor deep in the atmosphere coincide with balmier, drier conditions at higher altitudes — and vice versa.”

The team’s results were presented today, January 8, during the 221st meeting of the American Astronomical Society in Long Beach, CA.

Read more on the Spitzer site, and find the team’s paper in PDF form here.

Inset image: the anatomy of a brown dwarf’s atmosphere (NASA/JPL).

December 18, 2012December 23, 2015 by Jason Major

Behold! Hubble’s Heavenly Holiday “Ornament”

Planetary nebula NGC 5189 as seen by Hubble’s Wide Field Camera 3. Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)

It may be just a tad too big to hang on your tree but this bright, twisted planetary nebula would make a beautiful holiday ornament… if scaled a bit down to size, of course.

(Click the image to see it in its full festive glory!)

NGC 5189 is a planetary nebula that lies 1,800 light-years away in the southern constellation Musca. The gorgeous image above, acquired by Hubble’s Wide Field Camera 3 on October 8, 2012, shows the glowing streamers of oxygen, sulfur and hydrogen that are being blown far into space from the hot star star at its heart — HD 117622 (at right.)

The expelled gas forms a double structure, with a series of central blue lobes surrounded by a twisted helix of bright streamers, called radial filaments. These filaments are the result of fast-moving material from the star impacting previously expelled, slower-moving gas, which becomes visible due to ionizing radiation.

The twisted shapes — as opposed to the circular or spherical structures found in many planetary nebulae — may be the result of an unseen binary partner to HD 117622, which over time would affect its rotational orientation.

“The likely mechanism for the formation of this planetary nebula is the existence of a binary companion to the dying star,” said scientist Kevin Volk in a Gemini Observatory article from 2006. “Over time the orbits drift due to precession and this could result in the complex curves on the opposite sides of the star.”

The surrounding stars in the image were captured in visible and near-infrared light.

Read more on the Hubble site here, and check out a video below that zooms into the region of the sky where NGC 5189 is located:

Video credit: NASA, ESA, and G. Bacon (STScI)

December 13, 2012December 23, 2015 by Nancy Atkinson

The Truth About 2012: Killer Solar Flares Are a Physical Impossibility

NASA is trying to make sure that no one is taking the 2012 doomsday nonsense seriously, and just put out this video today detailing how a gigantic “killer solar flare” just ain’t gonna happen. Dr. Alex Young from the Goddard Space Flight Center explains how the Sun’s regular 11-year solar cycle is expected to peak in 2013 and 2014, not on December 21 of this year. Plus, this current solar cycle has been kind of a dud as far as wild activity goes, and scientists are not expecting the peak of this cycle to even be as strong as the previous one, which was rather mild.

Solar prominence in H alpha, with Earth scale model. Credit: John Brady.

Not to mention, Earth’s atmosphere keeps us well protected here on Earth. The only thing we do have to be concerned with is how solar flares and coronal mass ejections (CMEs) can damage satellites and even impact the power grid on Earth; additionally astronauts in Space to have to be specially protected as they are outside of the protection of the atmosphere.

You can get more information in our detailed article “2012: No Killer Solar Flare.”

November 25, 2012December 23, 2015 by Jason Major

Orion Revisited: Astronomers Find New Star Cluster in Front of the Orion Nebula

The well-known star-forming region of the Orion Nebula. Credit: Canada-France-Hawaii Telescope / Coelum (J.-C. Cuillandre & G. Anselmi)

Precise distances are difficult to gauge in space, especially within the relatively local regions of the Galaxy. Stars which appear close together in the night sky may actually be separated by many hundreds or thousands of light-years, and since there’s only a limited amount of space here on Earth with which to determine distances using parallax, astronomers have to come up with other ways to figure out how far objects are, and what exactly is in front of or “behind” what.

Recently, astronomers using the 340-megapixel MegaCam on the Canada-France-Hawaii Telescope (CFHT) observed the star-forming region of the famous Orion nebula — located only about 1,500 light-years away — and determined that two massive groupings of the nebula’s stars are actually located in front of the cluster as completely separate structures… a finding that may ultimately force astronomers to rethink how the many benchmark stars located there had formed.

Although the Orion nebula is easily visible with the naked eye (as the hazy center “star” in Orion’s three-star sword, hanging perpendicular below his belt) its true nebulous nature wasn’t identified until 1610. As a vast and active star-forming region of bright dust and gas located a mere 1,500 light-years distant, the various stars within the Orion Nebula Cluster (ONC) has given astronomers invaluable benchmarks for research on many aspects of star formation.

Now, CFHT observations of the Orion nebula conducted by Dr. Hervé Bouy of the European Space Astronomy Centre (ESAC) and Centre for Astrobiology (CSIC) and Dr. João Alves of the Institut für Astronomie (University of Vienna) have shown that a massive cluster of stars known as NGC 1980 is actually in front of the nebula, and is an older group of approximately 2,000 stars that is separate from the stars found within the ONC… as well as more massive than once thought.

“It is hard to see how these new observations fit into any existing theoretical model of cluster formation, and that is exciting because it suggests we might be missing something fundamental.”

– Dr. João Alves, Institut für Astronomie, University of Vienna

In addition their observations with CFHT — which were combined with previous observations with ESA’s Herschel and XMM-Newton and NASA’s Spitzer and WISE — have led to the discovery of another smaller cluster, L1641W.

According to the team’s paper, “We find that there is a rich stellar population in front of the Orion A cloud, from B-stars to M-stars, with a distinct 1) spatial distribution; 2) luminosity function; and 3) velocity dispersion from the reddened population inside the Orion A cloud. The spatial distribution of this population peaks strongly around NGC 1980 (iota Ori) and is, in all likelihood, the extended stellar content of this poorly studied cluster.”

The findings show that what has been known as Orion Nebula Cluster is actually a combination of older and newer groups of stars, possibly calling for a “revision of most of the observables in the benchmark ONC region (e.g., ages, age spread, cluster size, mass function, disk frequency, etc.)”

“We must untangle these two mixed populations, star by star, if we are to understand the region, and star formation in clusters, and even the early stages of planet formation,” according to co-author Dr. Hervé Bouy.

The team’s article “Orion Revisited” was published in the November 2012 Astronomy & Astrophysics journal. Read the CFHT press release here.

The Canada-France-Hawaii Telescope’s Mauna Kea summit dome in September 2009. Credit: CFHT/Jean-Charles Cuillandre

Inset image: Orion nebula seen in optical – where the molecular cloud is invisible – and infrared, which shows the cloud. Any star detected in the optical in the line of sight over the region highlighted in the right panel must therefore be located in the foreground of the molecular cloud. Credit: J. Alves & H. Bouy.