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.


 
 

 

Headlines May 29, 2015

News: U.S. Army chief opens door to embedding U.S. troops with Iraqi forces¬†- After the fall of Ramadi, the Iraqi Security Forces need military and political leadership, Gen. Raymond Odierno says.   Business: No acquisition strategy yet for LCS frigates¬†- Details of the new Littoral Combat Ship frigate program’s acquisition strategy are still being reviewed,...
 
 

News Briefs May 29, 2015

Finnish navy: Underwater intruder possible foreign submarine Finnish military officials say that an underwater object the navy chased last month in territorial waters and dropped several depth charges could have been a foreign submarine. A navy investigation released May 28 says that technical analysis did not provide sufficient proof of the presence of a submarine...
 
 
Lockheed Martin photograph by Chad Bellay

F-16 test pilots hit the ‘road’ to help train USAFE pilots

Air Force photograph by Airman 1st Class Kyla Gifford Three F-16s assigned to Spangdahlem Air Base, Germany, on a refueling mission last year. Two F-16 test pilots from the 416th Flight Test Squadron recently returned from a &#...
 

 
Navy photograph

Its reign in the fleet over, naval Sea King helicopter now rests at Pax Museum

Navy photograph At more than 54 feet in length with a 62-foot rotor diameter, the mighty SH-3A Sea King helicopter sits in its final spot at the Patuxent River Naval Air Museum. Designed as an anti-submarine warfare helicopter,...
 
 
boeing-korea

New Boeing Avionics Facility to enhance ROKAF readiness, affordability

Boeing formally opened a new avionics maintenance and repair center in the Yeongcheon Industry District of Daegu-Gyeongbuk Free Economic Zone May 28. The 10,000 square-foot facility will test and repair aircraft electrical syst...
 
 
Navy photograph by John F. Williams

ONR testing high-speed planing hulls

Navy photograph by John F. Williams A ship hull model attached to a high-speed sled moves through waves at the David Taylor Model Basin at Naval Surface Warfare Center, Carderock, during Office of Naval Research -sponsored rese...
 




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>