Source : Discover
Name : HB 209458b,nickname OSIRIS.
Location : 153 Light--Years from Earth in the comstellation Pegasus--a relatively close neighbor within our qalaxy.
Age : 4.5 billion years old,abt the same as Earth.
GENERAL CHARACTERISTICS :
Even within the exotic category of planets that circle other stars,the one revolving ard the star HD 209458 is special.Five yrs ago,David Chearbonneau of the harvard-smith--sonian center for Astrophspheric and Tim Brown of the national center for atmospheric Research in Boulder observed this planet pass in front of iys star once every three days,12hrs,and 35 mins,each time casting an extremely slight shadow.That shaow allows reing an extremely slight shadow.That shadow allows researchers to stretch their senses across 900 trillion miles of space and learn exactly wat a distant planet is like.
Charbonneau,Brown,and their collegues quickly began to nail dw the details.They timed the eclipses and determined that the planet follows a perfectly circular path ard HB 209458,obiting at a distance of 4.3 million miles.Another team had previously discovered the planet and measured
its mass---adt 220 times Earth's and roughly two-birds as much as jupiter's---based on the way it tugs on its parent star.The intensity of the eclipses shows the planet is abt 35 percent larger in circumference than jupiter.Together,the numbers paint a picture of a tortured world circling so close to its star that a year speeds by in just three and a half Earth days.The furious rays pounding dw on its alien palnet heat it to 2,000 degrees Fahrenheit and cause it to puff up like a marshmallow over a campfire.
Later oberservations led by alfred vidal-madjar at the astrophysics institude of Paris also exposed the smells of the planet,which he nicknamed OSIRIS.By watching starlight streaming through the planet's atmosphere,vidar-madjar discovered a cloud of hydrogen gas,as well as possible hints of oxygen and carbon,boiling off into space.The composition is abt wat you'd get if you put jupiter under an enormous heat lamp,suggesting that Osiris is made of the same stuff as the eclipses might reveal atmospheric layers,clouds,and even winds.
RANCE & POPULATION Roughly 10 percent of nearby sunlike stars have massive planets,so there may be 10 billion of them in our galaxy.Researchers know of nine eclipsing planets,including one that is bloated and another that is oddly dense.
HOW TP SPOT IT The star HD 209458 is visible thru binoculars.Lights from its planet has been directly observed only the spitzer space telescope,the image above is an artist's interpretion.
