Space is vast. So vast, in fact, that if a sun exploded shortly after the Big Bang, the light from the fire would have only brushed the Earth’s surface in the last few months. One such gamma-ray burst, believed to be 12.1 billion years old, was detected by Southern Methodist University in Dallas on April 19th. Since astronomers don’t know much about the shape or structure of the early universe, data from the burst will be trawled in order to glean more facts about where we all came from. In many ways, it’s a bit like getting a telegram from a long-deceased relative about buried treasure, except it’s nothing like that.
[Image credit: Southern Methodist University]
A new photo released by Nasa revealing a multi-coloured cluster of more than 100,000 stars has dazzled astronomers and fans of the Hubble Space Telescope.
The image shows the globular cluster known as Messier 5, or M5. In the description accompanying the picture, Nasa quotes a description from the 18th century astronomer Charles Messier’s catalogue of clusters and other nebulae. For this particular cluster, the fifth described in his catalogue, Messier began by writing “Beautiful Nebula discovered between the Balance [Libra] & the Serpent [Serpens] …”
The description is notable because it seems that M5 appeared to Messier to be a nebula, a cloud of space dust and gas, rather than a cluster of stars. It wasn’t until space observation technology was developed further that the definition was changed.
Nasa explained: “Though it appeared to Messier to be fuzzy and round and without stars, Messier 5 (M5) is now known to be a globular star cluster, 100,000 stars or more, bound by gravity and packed into a region around 165 light-years in diameter.”
The Universe is incredibly regular. The variation of the cosmos’ temperature across the entire sky is tiny: a few millionths of a degree, no matter which direction you look. Yet the same light from the very early cosmos that reveals the Universe’s evenness also tells astronomers a great deal about the conditions that gave rise to irregularities like stars, galaxies, and (incidentally) us.
That light is the cosmic microwave background, and it provides some of the best knowledge we have about the structure, content, and history of the Universe. But it also contains a few mysteries: on very large scales, the cosmos seems to have a certain lopsidedness. That slight asymmetry is reflected in temperature fluctuations much larger than any galaxy, aligned on the sky in a pattern facetiously dubbed “the axis of evil.”
The lopsidedness is real, but cosmologists are divided over whether it reveals anything meaningful about the fundamental laws of physics. The fluctuations are sufficiently small that they could arise from random chance. We have just one observable Universe, but nobody sensible believes we can see all of it. With a sufficiently large cosmos beyond the reach of our telescopes, the rest of the Universe may balance the oddity that we can see, making it a minor, local variation.
To measure the physical size of these anisotropies, researchers turn the whole-sky map of temperature fluctuations into something called a power spectrum. That’s akin to the process of taking light from a galaxy and finding the component wavelengths (colors) that make it up. The power spectrum encompasses fluctuations over the whole sky down to very small variations in temperature. (For those with some higher mathematics knowledge, this process involves decomposing the temperature fluctuations in spherical harmonics.)
A comparison between images taken with and without the MagAO system turned on. Image credits: Photograph by Laird Close
When it comes to visible light photos of the night sky, Hubble has been king. That’s because Earth-bound telescopes — even those with much higher-quality optical systems than Hubble — must deal with the blurring effects of our planet’s atmosphere.
A newly developed camera called VisAO, however, has done away with that problem, and in the process enabled astronomers to take the highest-resolution visible light photos ever captured of the night sky.
The camera system was developed over the course of 20 years thanks to the combined effort of astronomers from the University of Arizona, the Arcetri Observatory in Italy and the Carnegie Observatory. And when the latest version of the camera was finally deployed in the high desert of Chile at the Magellan 21 foot telescope, the results blew away the astronomers’ expectations.
Astronomers working at the European Southern Observatory (ESO) in Chile have discovered seven planets orbiting the star Gliese 667C.
Two exoplanets have been discovered in the star’s habitable zone, which has just the right range of distance where liquid water can exist on a planet’s surface.
A super-Earth is an extrasolar planet with a mass higher than Earth’s, but substantially below the mass of the Solar System’s smaller gas giants Uranus and Neptune, which are both more or less 15 Earth masses.
The term super-Earth refers only to the mass of the planet, and does not imply anything about the surface conditions or habitability.
Astronomers at the European Southern Observatory in Chile found out that 40 per cent of red dwarves are orbited by super-Earths. Red Dwarfs are by far the most common type of star in the Milky Way galaxy, so there might be tens of billions of such planets in our galaxy alone.
Dashing the hopes of those among them who believed the faraway world would surely prove habitable, astronomers from the Terxus II star system announced Thursday that a recently discovered planet remarkably like their own is in fact completely hostile to life.
An asteroid is whizzing past Earth on Friday — and it’s traveling with its own moon in tow.
1998 QE2, as NASA has named it, will not come anywhere near enough to collide with our world.
The closest it will come is about 3.6 million miles away — that’s over 15 times the distance to our moon. It will reach that point just before 5 p.m. ET.
But it’s giving astronomers the “best look at this asteroid ever,” NASA said.
Scientists have been rubbing their hands for a decade and a half for this opportunity since they discovered the asteroid on August 19, 1998, the year for which it is named. The letter “Q” stands for the month of August.
It may look like something from “The Lord of the Rings,” but this fiery swirl is actually a planetary nebula known as ESO 456-67. Set against a backdrop of bright stars, the rust-colored object lies in the constellation of Sagittarius (The Archer), in the southern sky.
Despite the name, these ethereal objects have nothing at all to do with planets; this misnomer came about over a century ago, when the first astronomers to observe them only had small, poor-quality telescopes. Through these, the nebulae looked small, compact, and planet-like — and so were labeled as such.
When a star like the sun approaches the end of its life, it flings material out into space. Planetary nebulae are the intricate, glowing shells of dust and gas pushed outwards from such a star. At their centers lie the remnants of the original stars themselves — small, dense white dwarf stars.
In this image of ESO 456-67, it is possible to see the various layers of material expelled by the central star. Each appears in a different hue — red, orange, yellow, and green-tinted bands of gas are visible, with clear patches of space at the heart of the nebula. It is not fully understood how planetary nebulae form such a wide variety of shapes and structures; some appear to be spherical, some elliptical, others shoot material in waves from their polar regions, some look like hourglasses or figures of eight, and others resemble large, messy stellar explosions — to name but a few.
The small near-Earth asteroid 2012 DA14 passed safely by Earth on Feb. 15, 2013. Its closest approach, about 17, 150 miles above the Indian Ocean, came at about 11:25 a.m. PST (2:55 p.m. EST and 1925 UTC). NASA’s Near-Earth Object Program Office accurately predicted the asteroid’s path and that there was no chance it might collide with Earth. The flyby did provide scientists and astronomers a unique opportunity to study a near-Earth object up close.
Astronomers say they have uncovered evidence for what could be four super-Earth planets orbiting within the habitable zones of two stars within 22 light-years of Earth.
Three of those candidate planets are among a tightly packed clutch of five that orbit Gliese 667C, part of a triple-star system 22 light-years away in the constellation Scorpius. The other possible planet is one of five orbiting tau Ceti, a sun-like star 12 light-years away in the constellation Cetus.
Taken together, the detections not only add to accumulating evidence that planets look to be more common than stars - and that planets in habitable zones could be more common than previously thought, some of researchers reporting the finds say.
The finds also illustrate the power of improved statistical tools to boldly uncover candidate planets where no planet had been found before.
The evidence for these candidate planets requires independent confirmation, the researchers caution. Still, the tools represent “a real breakthrough,” says Steven Vogt, an astronomer at the University of California at Santa Cruz and a member of the team reporting the results for tau Ceti. The approach the team took leaves only about one chance in 3 million that the detections could herald something other than a planet.