Dusty old star offers window Dusty old star offers window to our futureto our future--- GD 362 --- GD 362

Department of PhysicsDepartment of PhysicsNational Tsing Hua UniversityNational Tsing Hua University

G.T. ChenG.T. Chen2005/10/202005/10/20

GD 362GD 362

White Dwarf starWhite Dwarf star R.A. 17h 31m 34.33sR.A. 17h 31m 34.33s Dec. +37° 05' 20.6" Dec. +37° 05' 20.6" Distance: 22~26 pcDistance: 22~26 pc

It represents the end state of stellar It represents the end state of stellar evolution of stars like the Sunevolution of stars like the Sun

Its progenitor had an original mass Its progenitor had an original mass about seven times the Sun’sabout seven times the Sun’s

From the death of GD362,it passed From the death of GD362,it passed two to five billion years based on the two to five billion years based on the cooling ratecooling rate

This long time frame would explain This long time frame would explain why there is no sign of planetary why there is no sign of planetary nebula from the exclusion of material nebula from the exclusion of material as the star died as the star died

This star is as rich calcium, This star is as rich calcium, magnesium and iron elements as the magnesium and iron elements as the Sun’sSun’s

From the observation, there is a dust From the observation, there is a dust disk around the white dwarfdisk around the white dwarf

Why the disk can survive ?Why the disk can survive ?

something similar to the asteroid or something similar to the asteroid or possibly even a planet around the possibly even a planet around the star is being ground up and broken star is being ground up and broken to feed the star with dustto feed the star with dust

In the future , our solar system may In the future , our solar system may have the same conditions like this have the same conditions like this case GD 362case GD 362

ReferenceReference

http://spaceflightnow.com/news/http://spaceflightnow.com/news/ GEMINI OBSERVATORY NEWS RELEASEGEMINI OBSERVATORY NEWS RELEASE

Posted: September 26, 2005Posted: September 26, 2005 http://www.gemini.edu/home.phphttp://www.gemini.edu/home.php ApJ 632,119-122 , 2005ApJ 632,119-122 , 2005 A dusty disk around GD 362, a white dwaA dusty disk around GD 362, a white dwa

rf with uniquely high photospheric metarf with uniquely high photospheric metal abundance l abundance

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