Space

June 3, 2013

NASA’s Hubble will use rare stellar alignment to hunt for planets

NASA’s Hubble Space Telescope will have two opportunities in the next few years to hunt for Earth-sized planets around the red dwarf Proxima Centauri.

The opportunities will occur in October 2014 and February 2016 when Proxima Centauri, the star nearest to our sun, passes in front of two other stars. Astronomers plotted Proxima Centauri’s precise path in the heavens and predicted the two close encounters using data from Hubble.

“Proxima Centauri’s trajectory offers a most interesting opportunity because of its extremely close passage to the two stars,” said Kailash Sahu, an astronomer with the Space Science Telescope Institute in Baltimore, Md. Sahu leads a team of scientists whose work he presented Monday at the 222nd meeting of American Astronomical Society in Indianapolis.

Red dwarfs are the most common class of stars in our Milky Way galaxy. Any such star ever born is still shining today. There are about 10 red dwarfs for every star like our sun. Red dwarfs are less massive than other stars. Because lower-mass stars tend to have smaller planets, red dwarfs are ideal places to go hunting for Earth-sized planets.

Previous attempts to detect planets around Proxima Centauri have not been successful. But astronomers believe they may be able to detect smaller terrestrial planets, if they exist, by looking for microlensing effects during the two rare stellar alignments.

Microlensing occurs when a foreground star passes close to our line of sight to a more distant background star. These images of the background star may be distorted, brightened and multiplied depending on the alignment between the foreground lens and the background source.

These microlensing events, ranging from a few hours to a few days in duration, will enable astronomers to measure precisely the mass of this isolated red dwarf. Getting a precise determination of mass is critical to understanding a star’s temperature, diameter, intrinsic brightness and longevity.

Astronomers will measure the mass by examining images of each of the background stars to see how far the stars are offset from their real positions in the sky. The offsets are the result of Proxima Centauri’s gravitational field warping space. The degree of offset can be used to measure Proxima Centauri’s mass. The greater the offset, the greater the mass of Proxima Centauri. If the red dwarf has any planets, their gravitational fields will produce a second small position shift.

Because Proxima Centauri is so close to Earth, the area of sky warped by its gravitation field is larger than for more distant stars. This makes it easier to look for shifts in apparent stellar position caused by this effect. However, the position shifts will be too small to be perceived by any but the most sensitive telescopes in space and on the ground. The European Space Agency’s Gaia space telescope and the European Southern Observatory’s Very Large Telescope on Mt. Cerro Paranal in Chile may be able to make measurements comparable to Hubble’s.

To identify possible alignment events, Sahu’s team searched a catalog of 5,000 stars with a high rate of angular motion across the sky and singled out Proxima Centauri. It crosses a section of sky with the apparent width of the full moon as observed from Earth every 600 years.




All of this week's top headlines to your email every Friday.


 
 

 

NASA partners punctuate summer with spacecraft development advances

Spacecraft and rocket development is on pace this summer for NASA’s aerospace industry partners for the agency’s Commercial Crew Program as they progress through systems testing, review boards and quarterly sessions under their† Space Act Agreements with the agency. NASA engineers and specialists continue their review of the progress as the agency and partners move...
 
 

NASA seeks proposals for commercial Mars data relay satellites

NASA has issued a Request for Information to investigate the possibility of using commercial Mars-orbiting satellites to provide telecommunications capabilities for future robotic missions to the Red Planet. We are looking to broaden participation in the exploration of Mars to include new models for government and commercial partnerships, said John Grunsfeld, associate administrator of NASAR...
 
 
NASA photograph

NASA’s Chandra X-ray Observatory celebrates 15th anniversary

NASA photograph To celebrate the 15th anniversary of NASA’s Chandra X-ray Observatory, four new images of supernova remnants are being released. These spectacular cosmic vistas are the glowing debris fields that were crea...
 

 
NASA photograph

NASA begins engine test project for space launch system rocket

NASA photograph RS-25 rocket engine No. 0525 is positioned onto the A-1 Test Stand at NASAís Stennis Space Center in Mississippi preparation for a series of developmental tests. Engineers have taken a crucial step in preparing...
 
 

SSL selected to study asteroid retrieval for NASA

Space Systems/Loral, a leading provider of commercial satellites, announced July 18 that it was one of the companies selected by NASA to study system concepts and key technologies for NASA’s Asteroid Redirect Mission, which is expected to be a key part of the agency’s path to sending humans to Mars. SSL will conduct two studies;...
 
 
NASA image

NASA turns over next-gen air traffic management tool to FAA

NASA image As seen in this image, Terminal Sequencing and Spacing technology enables air traffic controllers to better manage the spacing between aircraft as they save both time and fuel and reducing emissions, flying more effi...
 




0 Comments


Be the first to comment!


Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>