Earth-sized planet around Alpha Centauri B discovered

[orb]

We have an exoplanet in our neighborhood!

European astronomers have discovered a planet with about the mass of the Earth orbiting Alpha Centauri B -- the nearest exoplanet, just 4.4 light-years away. It's also the lightest exoplanet ever discovered around a star like the Sun. The planet's mass is similar to Earth's, but its orbit is 10 times closer to the star than Mercury orbits the Sun. The planet was detected using the HARPS instrument on the 3.6-meter telescope at ESO's La Silla Observatory in Chile.

"Our observations extended over more than four years using the HARPS instrument and have revealed a tiny, but real, signal from a planet orbiting Alpha Centauri B every 3.2 days," says Xavier Dumusque (Geneva Observatory, Switzerland, and Centro de Astrofisica da Universidade do Porto, Portugal), lead author of the paper. "It's an extraordinary discovery and it has pushed our technique to the limit!"

The European team detected the planet by picking up the tiny wobbles in the motion of the star Alpha Centauri B created by the gravitational pull of the orbiting planet. The effect is minute -- it causes the star to move back and forth by no more than 51 centimeters per second (1.8 km/hour), about the speed of a baby crawling. This is the highest precision ever achieved using this method.

Links:

• ESO: Planet Found in Nearest Star System to Earth
  
  
• Nature: The exoplanet next door
  
  
• Science News: The alien next door
  
  
• Discovery News: Earth-Sized World Found Next Door
  
  
• SPACE.com:
  • Discovery! Earth-Size Alien Planet at Alpha Centauri Is Closest Ever Seen
  • Images: Closest-Ever Alien Planet, the Earth-Size Alpha Centauri Bb
  • 'Next-Door' Alien Planet Still Too Distant to Visit — for Now
  • Earth-Size Planet Closest to Our Solar System: By The Numbers
  
  
• SpaceRef: Alpha Centauri B Has An Earth-Mass Planet
  
  
• Universe Today: Next Door Neighbors? Earth-Sized Planet Discovered in Nearest Star System to Us
  
  
• Discover Magazine - Bad Astronomy: ALPHA CENTAURI HAS A PLANET!
  
  
• Science Daily: Planet Found in Nearest Star System to Earth: HARPS Instrument Finds Earth-Mass Exoplanet Orbiting Alpha Centauri B
  
  
• Space Daily: Nearest Star Has Earth Mass Planet
  
  
• NewScientist:
  • First planet found in star system next door
  • An exo-tourist's guide to our closest alien planet
  
  
• Spaceflight Now: Earth-sized planet found around star next door to sun
  
  
• Sky & Telescope: Planet Found in Alpha Centauri System
  
  
• Astronomy Now: Rocky planet orbiting one of our stellar neighbours
  
  
• Scientific American: The Exoplanet Next-Door: Astronomers Discover World in Nearest Star System
  
  
• AmericaSpace: Astronomers Find Earth-Sized Planet Orbiting Alpha Centauri B
  
  
• Aviation Week: New Planet Discovered In Earth's Back Yard
  
  
• The Planetary Society Blog: First Planet Discovered in Alpha Centauri System

VideoFromSpace:

 

[sorindafabico]

THIS IS AMAZING

---------- Post added at 10:36 PM ---------- Previous post was at 10:31 PM ----------

Please, resurrect [ame="http://en.wikipedia.org/wiki/Project_Longshot"]Project Longshot[/ame] NOW!!

 

[garyw]

This planet is way to close to a star to be interesting. Better to wait until we have an Earth like planet around a star that is still relatively close to Earth. Still, it's a good find and hopefully being this close presents a wonderful opportunity for extended and detailed study.

 

[sorindafabico]

Ok, calming down ...

Even if it is a planet like Mercury, it would still be a great opportunity to study, because it's a "close" exoplanet. But we can also expect to detect possible "friendly" planets there.

 

[N_Molson]

but its orbit is 10 times closer to the star than Mercury orbits the Sun.

That's very very close ; even sending a probe to it could prove to be very challenging.

But anyway, right now Alpha Centauri B is still an infinity away (well, nearly 4000 years if I remember) given the speeds of our probes...

 

[Pipcard]

Being able to detect an Earth-sized planet is one more step towards finally discovering an Earth-like planet.

 

[dgatsoulis]

For an Earth-sized planet, it has a relatively large impact to the motion of Alpha Centauri B, due to its proximity to the star.

For comparison, Earth induces a 9 centimeters per second "wobble" to the Sun, while the much more massive Jupiter, at about 5 times the distance, induces a motion of ~ 15 m/s.

The accuracy of the telescopes and techniques the astronomers use, always amazes me. Detecting a ½ m/s change in the motion of a star 45 trillion kilometers away, is mind-blowing.

 

[Zachstar]

If it is anything that could really encourage us to develop FTL in the long run is this constant stream of discoveries of planets in places such as Alpha Centauri.

Mid Term goal should be obviously colonies outside of Earth. Yet long term is survival in entirely new solar systems.

 

[Hielor]

 

[SiberianTiger]

Valtu!

 

[Zatnikitelman]

WOOHOO!!! I know a planet that close the star isn't exactly an ideal candidate for life, but to finally find one in the next system over, and an exoplanet period that's about Earth-mass is great!

 

[N_Molson]

If it is anything that could really encourage us to develop FTL in the long run

Let's hope that Albert was wrong

 

[Codz]

Fantastic news!

 

[Kyle]

This might be one of the greatest discoveries in exoplanets yet. An earth like system orbiting Alpha Centauri? This is HUGE!

 

[Gerdih]

Amazing!! I assumed that there won't be any planet because I thought them would have been discovered time ago, and now this! Who knows if there is something in the habitable zone.

 

[fsci123]

Oh My God... I personally never thought that they were going to discover a planet there... I wonder could this discovery boost the nasa budget a little bit...


:banana::woohoo::RnR1:

 

[Izack]

It’s an extraordinary discovery and it has pushed our technique to the limit!

I would say it has pushed the technique well past its previous limits. As dgatsoulis said above, they've detected an oscillation peaking at 0.5 m/s in an object 45 trillion kilometres away. That is absolutely incredible.

 

[dgatsoulis]

Amazing!! I assumed that there won't be any planet because I thought them would have been discovered time ago, and now this! Who knows if there is something in the habitable zone.

It would pretty difficult to detect. But they were able to detect 0.51 m/s (Not 0.5 or 0.6 m/s). That means they can detect up to 1cm/s change in motion, which is astonishing.

The radius of the middle of the habitable zone for Proxima Centauri B (0.9 solar masses, 0.5 luminosity) is ~ 0.87AU. An Earth sized object at such an orbit would create a "wobble" of ~ 0.1 m/s (Similar to the Earth-Sun motion). At that range noise becomes a significant factor in the measurements, but it doesn't mean that it can't be done.

 

[orb]

NASA News Release:
RELEASE : 12-366
NASA Statement On Alpha Centauri Planet Discovery

Oct. 17, 2012

WASHINGTON -- The following is a statement about the European Southern Observatory's latest exoplanet discovery from NASA's Science Mission Directorate Associate Administrator, Dr. John Grunsfeld.

"We congratulate the European Southern Observatory team for making this exciting new exoplanet discovery. For astronomers, the search for exoplanets helps us understand our place in the universe and determine whether Earth is unique in supporting life or if it is just one member of a large community of habitable worlds. NASA has several current and future missions that will continue in this search.

"An example is NASA's Kepler mission. It was specifically designed to survey a specific region of our Milky Way galaxy to detect Earth-size and smaller planets in or near the habitable zone -- that region around a star where it is theoretically possible for a planet to maintain liquid water on its surface -- and determine the fraction of the hundreds of billions of stars in our galaxy that might have such planets. Kepler works very differently from HARPS. Rather than detecting the wobble in the host star, Kepler detects the slight dimming of a star when a planet passes in front of it.

"NASA's Hubble and Spitzer space telescopes have contributed to the study of exoplanets. Using their photometric and spectroscopic sensitivity, these space telescopes have made the first steps in characterizing the atmospheres of planets around other stars. They can only do this when the exoplanets pass serendipitously in front of its star, allowing the space telescope to study light that has filtered through the planet's atmosphere.

"NASA's James Webb Space Telescope (JWST) will provide a unique facility that will serve through the next decade as the mainstay for characterization of transiting exoplanets. The main transit studies JWST will be able to undertake are: discovery of unseen planets, determining exoplanet properties like mass, radius, and physical structure, and characterizing exoplanet atmospheres to determine things like their temperature and weather. If there are other planets in the Alpha Centauri system farther from the star, JWST may be able to detect them as well through imaging.

"NASA is also studying two medium-class exoplanet missions in our Explorer program, and in the spring of 2013 will select one of them to enter development for flight later in the decade."

{...}

 

[Screamer7]

It looks like the nearer a Star is to us, the more difficult it is to detect planets around the star.
I wonder why?
Maybe it is something to do with it's glare.
The closer a star is, the more brilliant does it shine?
Well, it's time to run Space Engine again.........