Second smallest exoplanet spotted
Washington: Astronomers have spotted an extrasolar planet with a mass just four times that of Earth.
Experts from the California Institute of Technology (Caltech) and other institutions made the finding using the highly sensitive 10-meter Keck I telescope atop Hawaii`s Mauna Kea.
The planet orbits its parent star HD156668 about once every four days.
The planet dubbed HD 156668b is the second-smallest world among the more than 400 exoplanets (planets located outside our solar system) known to man.
The discovery was made using the radial velocity or wobble method, which relies on Keck`s High Resolution Echelle Spectrometer (HIRES) to spread light collected from the telescope into its component wavelengths or colors, producing a spectrum.
As the planet orbits the star, it causes the star to move back and forth along our line of sight, which causes the starlight to become redder and then bluer in a periodic fashion.
The color shifts give astronomers the mass of the planet and the characteristics of its orbit, such as how much time it takes to orbit the star.
John A Johnson, assistant professor of astronomy at Caltech and codiscoverer of the new planet said: "If the stars themselves have imperfections and are unstable, their wobbling would cause jumps in velocity that could mimic or hide the existence of a planet."
He added: "We have been doing simulations to understand the astrophysics of these imperfections, and how to distinguish them from the signals from a planet. We hope to use these simulations to design even better observing strategies and data-analysis techniques."
However, he explained that discovery of a planet that is comparable in size to Earth and found within the habitable zone, "will require a great deal of work."
He added: "If we could build the best possible radial-velocity instrument tomorrow, we might have answers in three years, and a solid census of Earthlike planets within a decade. We``ll need gigantic leaps in sensitivity to get there, and we``re hot on the trail."
Johnson is also presently working on building a new camera for the 60-inch telescope that will allow astronomers to search for the passages-or transits-of low-mass planets like HD156668.
He concluded: "If we catch the planet in transit, we can measure the planet``s radius and density, and therefore address the question of whether the planet has a composition more like Earth, with a solid surface and thin atmosphere, or is a miniature version of Neptune, with a heavy gaseous atmosphere."
The discovery made with support from NASA``s Eta-Earth Survey for Low-Mass Planets was announced at the 215th American Astronomical Society meeting in Washington, D.C.
More from India
More from World
More from Sports
More from Entertaiment
- Vadodara: Policemen seen dancing with bar girls
- PM Modi speaks at Golden Jubilee celebrations of poet Dinkar’s works
- Zee Media Exclusive: Kangana, Madhavan talk about their film 'Tanu Weds Manu Returns'
- DNA: Harmful chemicals found in Maggi, Nestle India still in denial mode
- One year of Modi govt: Arun Jaitley addresses press conference
- CM Kejriwal shortlists 39 'unwanted' IAS officers in Delhi
- Zee Media Exclusive interview with Congress leader Kamal Nath
- DNA: Modi-led NDA govt's hits and misses in one year
- Rajasthan: Gujjars revive reservation agitation, block rail track
- J Jayalalithaa sworn-in as Chief Minister of Tamil Nadu
- Mumbai: One injured in shootout at Film City
- Delhi: Car catches fire after crash, one dead
- ISIS to buy first nuclear weapon from Pak?
- Mumbai: CCTV captures assailant with gun at Film City
- Dr Subhash Chandra Show: Aspiring for more than what you have!
- IPL 2015, Qualifier 2: CSK vs RCB - As it happened...
- Tanu Weds Manu Returns movie review: Kangana Ranaut steals the show!
- India to soon have its own space shuttle!
- Kejriwal slams notification on LG's powers, says Modi running Delhi govt through back door
- PM Narendra Modi graces Digvijay Singh's son wedding reception
- Rahul Gandhi to pressurise govt to act on one-rank-one-pension issue
- Goa Board SSC Exam Results 2015 announced
- CBSE 12th Results 2015: CBSE Board Cbse.nic.in & cbseresults.nic class 12th XII board exam Results 2015 date announced
- ISIS close to buying nuclear weapon from Pakistan?
- Businessman shot next to Amitabh Bachchan's shooting location in Mumbai Film City
- Manohar Parrikar visits forward areas along LoC, reviews security situation
- RBSE 12th Science & Commerce Board Result 2015 declared
- There will be no delay in appointing CIC, CVC: Jitendra Singh
- rajresults.nic.in RBSE Rajasthan Board BSER Class 12th Science and Commerce Exam Results 2015 to be declared shortly
- RBSE rajresults.nic.in & rajeduboard.nic.in 12th Results 2015: BSER Ajmer Rajasthan Board Class 12th XII Senior Secondary Science & Commerce Exam Results 2015 declared