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Explanation: In 185 AD, Chinese astronomers recorded the appearance of a new star in the Nanmen asterism. That part of the sky is identified with Alpha and Beta Centauri on modern star charts. The new star was visible to the naked-eye for months, and is now thought to be the earliest recorded supernova. This deep telescopic view reveals the wispy outlines of emission nebula RCW 86, just visible against the starry background, understood to be the remnant of that stellar explosion. Captured by the wide-field Dark Energy Camera operating at Cerro Tololo Inter-American Observatory in Chile, the image traces the...

Explanation: This 180 degree panoramic night skyscape captures our Milky Way Galaxy as it arcs above the horizon on a winter's night in August. Near midnight, the galactic center is close to the zenith with the clear waters of Lake Traful, Neuquen, Argentina, South America, planet Earth below. Zodiacal light, dust reflected sunlight along the Solar System's ecliptic plane, is also visible in the region's very dark night sky. The faint band of light reaches up from the distant snowy peaks toward the galaxy's center. Follow the arc of the Milky Way to the left to find the southern hemisphere...

Toward a High-Velocity Astronomyby Paul Gilsteron May 15, 2019 Couple the beam from a 100 gigawatt laser with a single-layer lightsail and remarkable things can happen. As envisioned by scientists working with Breakthrough Starshot, a highly reflective sail made incredibly thin — perhaps formed out of graphene and no thicker than a single molecule — could attain speeds of 20 percent of c. That’s good enough to carry a gram-scale payload to the nearest stars, the Alpha Centauri triple system, with a cruise time of 20 years, for a flyby followed by an agonizingly slow but eventually complete data return....

Despite being only 4.3 light-years away from Earth, the trio of stars comprising Alpha Centauri still holds a lot of mysteries. It being the closest star system to us, you'd think we'd have teased out most of its secrets by now, but in fact we're still learning basic stuff about it. We know some of the basics, of course. The system has two stars that orbit each other in a binary, one of which (called Alpha Centauri A) is much like the Sun and the other (Alpha Cen B) is a tad smaller and cooler. Nearby is a third star,...

There may be small, rocky planets in the nearby Alpha Centauri triple-star system that have been overlooked, according to a new study published in the Astronomical Journal Alpha Centauri, also known as Rigil Kentaurus, Rigil Kent and Gliese 559, is the closest stellar system to Earth. This triple system is made up of the bright binary star formed by Alpha Centauri A and B, plus the faint red dwarf star Alpha Centauri C. The two brighter components are roughly 4.35 light-years away from us. Alpha Centauri C, better known as Proxima Centauri, is slightly closer, at 4.23 light-years. Compared to...

The proposed journey, which was revealed by scientists with NASA’s Jet Propulsion Laboratory at the 2017 Geophysical Union Conference and reported by New Scientist, was born out of a budget mandate to make progress on interstellar travel. Now, NASA is working on technology that, if all goes as planned, could allow a spacecraft to reach ten percent of light speed, and the goal is to have it ready by 2069 with Alpha Centauri in its sights. ... The system is around 4.3 light years from Earth, which essentially makes it a next-door neighbor. If NASA succeeds at achieving ten percent...

So... it could still get us to Mars in 70 days? Physicists have just published a new paper that suggests the controversial EM drive - or electromagnetic drive - could actually work, and doesn't defy Newton's third law after all. In case you've missed the hype, here's a quick catch-up: a lot of space lovers are freaking out about the EM drive because of claims it could get humans to Mars in just 10 weeks, but just as many are sick of hearing about it, because, on paper at least, it doesn't work within the laws of physics. Despite that...

Explanation: Triggered by the impact of a coronal mass ejection on New Year's eve, a moderate geomagnetic storm brought a celebration of sky lights to planet Earth's high latitudes yesterday. In this New Year's nightscape, the shimmering reddish curtains of aurora australis along a southern horizon are captured over Morgiana, SW Victoria, Australia. Of course, more permanent jewels of the southern skies are on the scene. The southern Milky Way, Alpha and Beta Centauri, and bright stars of the Southern Cross are on the left. In silhouette, branches of the large foreground tree stretch across the Milky Way's satellite galaxies,...

Explanation: The Henbury craters in the Northern Territory, Australia, planet Earth, are the scars of an impact over 4,000 years old. When an ancient meteorite fragmented into dozens of pieces, the largest made the 180 meter diameter crater whose weathered walls and floor are lit in the foreground of this southern hemisphere nightscape. The vertical panoramic view follows our magnificent Milky Way galaxy stretching above horizon, its rich central starfields cut by obscuring dust clouds. A glance along the galactic plane also reveals Alpha and Beta Centauri and the stars of the Southern Cross. Captured in the region's spectacular, dark...

What are the chances that we’ll find habitable planets around Alpha Centauri A and B? Centauri Dreams has long kept an eye on the work of Greg Laughlin (UC-Santa Cruz) and colleagues, who have been working on the Alpha Centauri question with ever more interesting results. Following their work on Greg’s systemic site has been fascinating, and for those who would like to be quickly brought up to speed, it’s useful to know that Laughlin has made their recent paper summarizing these findings available online. Anyone serious about the study of these closest stars to Earth will want to download...

Results from exoplanet surveys indicate that small planets (super-Earth size and below) are abundant in our Galaxy. However, little is known about their interiors and atmospheres. There is therefore a need to find small planets transiting bright stars, which would enable a detailed characterisation of this population of objects. We present the results of a search for the transit of the Earth-mass exoplanet Alpha Centauri Bb with the Hubble Space Telescope (HST). We observed Alpha Centauri B twice in 2013 and 2014 for a total of 40 hours. We achieve a precision of 115 ppm per 6-s exposure time in...

Stars Passing Close to the Sunby Paul Gilster on January 2, 2015 Every time I mention stellar distances I’m forced to remind myself that the cosmos is anything but static. Barnard’s Star, for instance, is roughly six light years away, a red dwarf that was the target of the original Daedalus starship designers back in the 1970s. But that distance is changing. If we were a species with a longer lifetime, we could wait about eight thousand years, at which time Barnard’s Star would close to less than four light years. No star shows a larger proper motion relative to...

The nearest single Sun-like star to the Earth hosts five planets - one of which is in the "habitable zone" where liquid water can exist, astronomers say. Tau Ceti's planetary quintet - reported in an online paper that will appear in Astronomy and Astrophysics - was found in existing planet-hunting data. The study's refined methods of sifting through data should help find even more far-flung worlds. The star now joins Alpha Centauri as a nearby star known to host planets. In both those cases, the planets were found not by spying them through a telescope but rather by measuring the...

Explanation: Located just next door, Alpha Centauri is the closest star system to the Sun. A view from our interstellar neighbor a mere 4.3 light-years away is shown in this illustration. The Sun is at the upper right, a bright star against the background of the Milky Way. The crescent in the foreground is an artist's rendering of a planet now reported orbiting Alpha Centauri B, making it the closest known exoplanet. Discovered by astronomer Xavier Dumusque et al. using the planet hunting HARPS instrument to measure minute shifts in the star's spectrum for more than four years, the planet...

European astronomers have discovered a planet with about the mass of the Earth orbiting a star in the Alpha Centauri system -- the nearest to Earth. It is also the lightest exoplanet ever discovered around a star like the Sun. The planet was detected using the HARPS instrument on the 3.6-meter telescope at ESO's La Silla Observatory in Chile. The results will appear online in the journal Nature on 17 October 2012.

European astronomers have discovered a planet with about the mass of the Earth orbiting a star in the Alpha Centauri system — the nearest to Earth. It is also the lightest exoplanet ever discovered around a star like the Sun. The planet was detected using the HARPS instrument on the 3.6-metre telescope at ESO’s La Silla Observatory in Chile. The results will appear online in the journal Nature on 17 October 2012.

[This is cool! While the planet discovered is too hot for life, there probably are others and some might be in that orbit where water can be liquid and life can exist. So maybe with future ion drive ships, suspended animation, or whatever human colonies might be established there. Neat!] Bringing the search for another Earth about as close as it will ever get, a team of European astronomers was scheduled to announce on Wednesday that it had found a planet the same mass as Earth’s in Alpha Centauri, a triple star system that is the Sun’s closest neighbor, only...

Explanation: The glare of Alpha Centauri, one of the brightest stars in planet Earth's night sky, floods the left side of this southern skyscape. A mere 4.3 light-years distant, Alpha Centauri actually consists of two component stars similar in size to the Sun, locked in a mutual orbit. Much smaller and cooler, a third member of the same star system, Proxima Centauri, lies outside this field of view. Still, the telescopic scene does reveal often overlooked denizens of the Milky Way's crowded galactic plane that lie beyond the glare of Alpha Centauri, including a planetary nebula cataloged as Hen 2-111,...

Explanation: On December 24, Comet Lovejoy rose in dawn's twilight, arcing above the eastern horizon, its tails swept back by the solar wind and sunlight. Seen on the left is the comet's early morning appearance alongside the southern Milky Way from the town of Intendente Alvear, La Pampa province, Argentina. The short star trails include bright southern sky stars Alpha and Beta Centauri near the center of the frame, but the long bright streak that crosses the comet tails is a little closer to home. Waiting for the proper moment to start his exposure, the photographer has also caught the...

Explanation: The closest star system to the Sun is the Alpha Centauri system. Of the three stars in the system, the dimmest -- called Proxima Centauri -- is actually the nearest star. The bright stars Alpha Centauri A and B form a close binary as they are separated by only 23 times the Earth- Sun distance - slightly greater than the distance between Uranus and the Sun. In the above picture, the brightness of the stars overwhelm the photograph causing an illusion of great size, even though the stars are really just small points of light. The Alpha Centauri system...