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Mystery of explosive star solved

By Ker ThanSPACE.com

(SPACE.com) -- In Febrary! a faint star a fe" t#osand li$#t-years a"ay flared sddenly! beamin$

so bri$#tly t#at for a fe" days it "as visible to t#e na%ed eye.

The star is a stellar corpse the size of Earth, known as a white dwarf, and it is paired in a binary system with a red iant,a dyin, bloated star that once resembled o!r s!n. The red iant has been d!mpin as onto the s!rface of the whitedwarf, and e"ery few years, eno!h matter acc!m!lates to set off a iant thermon!clear e#plosion.

$t was one of these e#plosions, called a %no"a,% that astronomers and starazers detected earlier this year.

The two&star system, called 'S (phi!chi, is known as a rec!rrent no"a beca!se fi"e similar er!ptions ha"e beendetected before. The first obser"ation occ!rred in )*+* the last er!ption prior to this latest one happened in )+*-.

The new obser"ations, made !sin ad"anced radio and &ray telescopes not a"ailable d!rin the last o!tb!rst, re"ealthe e#plosion to be more comple# than was pre"io!sly ass!med.

Standard comp!ter models had predicted a spherical e#plosion with matter e/ected in all directions e0!ally. The latestobser"ations instead showed that the e#plosion e"ol"ed into two lobes, confirmin s!spicions that the no"a o!tb!rstprod!ces twin /ets of stellar material that spews o!t from the white dwarf in opposite directions.

%The radio imaes represent the first time we1"e e"er seen the birth of a /et in a white dwarf system. 2e literally see the/et 1t!rn on,1% said 3ichael '!pen, an astronomer at the 4ational 'adio Astronomy (bser"atory who st!died 'S(phi!chi !sin the 5ery 6on Baseline Array 756BA8.

As impressi"e as the no"a are, they miht /!st be prec!rsors for a more "iolent s!perno"a e#plosion that will occ!r inthe f!t!re, scientists say.

The white dwarf1s thermon!clear blasts are similar to those that occ!r on the s!rface of the s!n, b!t they can be o"er)99,999 times more powerf!l. :!rin each o!tb!rst, an amo!nt of as e0!al to the mass of the Earth is fl!n intospace.

Some of this e/ected matter slams into the e#tended atmosphere of the inflated red iant, creatin blast wa"es thataccelerate electrons to nearly the speed of liht. As the electrons tra"el thro!h the stars1 manetic fields, they emitradio wa"es that can be detected by telescopes on Earth.

The blast wa"es mo"e at o"er fo!r million miles 7abo!t ;.< million kilometers8 per ho!r. =or a few weeks d!rin eacho!tb!rst, the white dwarf becomes a red iant.

%After the >thermon!clear e#plosion?, the white dwarf will p!ff !p into a red iant for a few weeks as the hydroen thathas been blasted into space f!ses into heli!m,% e#plains 'ichard Barry of the 4ASA @oddard Space =liht Center in3aryland.

All eyes on &p#ic#i

apanese astronomers first detected sins of 'S (phi!chi1s latest no"a on the niht of =ebr!ary ). =ollow&!pobser"ations by radio telescopes re"ealed an e#pandin blast wa"e whose diameter was already the size of Sat!rn1sorbit aro!nd the S!n.

$n the weeks followin, se"eral radio and &ray telescopes aro!nd the world tracked 'S (phi!chi closely, incl!din the3E'6$4 array in the K, the E!ropean E54 array, the 5ery 6on Baseline Array 756BA8 and 5ery 6are Array 756A8 inthe nited States, and 4ASA1s Swift and 'ossi &ray Timin E#plorer satellites.

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=indins from the 'ossi &ray Timin E#plorer and the 56BADE54 obser"ations are detailed in two separate st!diesp!blished in the !ly 9 iss!e of the /o!rnal 4at!re.

The red iant and white dwarf stars makin !p 'S (phi!chi are separated by abo!t ).- astronomical !nits, or one anda half times the distance the Earth is from the s!n. The binary star system is located in the constellation (phi!ch!s,abo!t -,999 liht&years away && "ery close by astronomical standards.

%2e ha"e a rinside seat for this "ery important e"ent,% Barry told SPACE.com. Barry is a co&a!thor on another st!dyon 'S (phi!chi that will appear in an !pcomin edition of Astrophysical o!rnal.

Spernova precrsor'

2hen the o!tb!rst is o"er, as will once aain b!ild !p on the white dwarf and the e#plosions will bein anew, perhapsin some 9 years time. $t1s !nknown whether the white dwarf casts off all of its acc!m!lated matter d!rin eacher!ption, or whether some of the material is bein hoarded and slowly increasin the mass of the dead star.

%$f the white dwarf is increasin in mass then it will e"ent!ally be ripped apart in a titanic s!perno"a e#plosion and thecycle of o!tb!rsts will come to an end,% said Tim (1Brien of the ni"ersity of 3anchester, a co&a!thor on one of the4at!re st!dies.

2hite dwarfs m!st attain a critical ).< solar masses before they can e#plode in what scientists call a Type )as!perno"a. The white dwarf in 'S (phi!chi is near this critical limit now, b!t it will still probably need h!ndreds oftho!sands of years to acc!m!late the final bit of mass, scientists say.

Beca!se all Type )a s!perno"as emit the same amo!nt of liht at their peak, they ser"e as important %standardcandles% which astronomers !se to calc!late cosmic distances.

%(!r !nderstandin of these ob/ects is e#ceedinly important as any miscalc!lation or !ncertainty in the total liht ofo!tp!t of s!perno"ae co!ld ha"e a dramatic effect on o!r calc!lations of the scale and size of the entire !ni"erse,%Barry said.

Costa ican lab to test plasma space roc%et

I*EIA! Costa ica (eters) -- *etter %no"n for coffee! srfin$ and +n$les! tiny tropical Costaica is no" #ome to scientists "or%in$ on a plasma roc%et en$ine t#ey #ope "ill slas# travel timesto t#e moon and beyond.

6ed by Costa 'ican&born former 4ASA space sh!ttle astrona!t =ranklin Chan&:iaz, the o!ston&based Ad Astra'ocket Company ina!!rated a site last weekend in the Central American nation to test rocket components.

The company hopes to sell the finished rocket enine, propelled by s!per&hot plasma, to 4ASA for moon trips plannedfor the ne#t decade and an e"ent!al l!nar space station.

Scientists belie"e rockets that r!n on plasma, the st!ff that makes stars shine, will be faster than rockets c!rrently !sedin space tra"el.

Considered the fo!rth state of matter beca!se it is neither a solid, li0!id or as, plasma is a hih enery form of matter

that can reach millions of derees, makin it a potentially powerf!l f!el.

Closer to home, plasma is fo!nd in lihtnin bolts and neon sins.

Chan&:iaz said he located the laboratory in the Costa 'ican town of 6iberia with the hope it will plant the seeds ofspace&ae ind!stry in a de"elopin co!ntry that depends on to!rism for m!ch of its income.

%E"ent!ally as o!r people learn from e#perience they co!ld desin components, and that wo!ld become intellect!alproperty of Costa 'ica,% Chan&:iaz said in a recent inter"iew.

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The e#treme power of his proposed rocket, which !ses 5ariable Specific&$mp!lse 3anetoplasma 'ocket, or 5AS$3',technoloy, concei"ed in the )+F9s, co!ld e"ent!ally c!t tra"el time to 3ars by abo!t a third, he said.

Chan&:iaz, a physicist, helped de"elop 5AS$3' d!rin se"eral space sh!ttle missions after he /oined 4ASA in the)+*9s.

A prototype of the rocket, to be b!ilt in Ad Astra1s o!ston laboratory, sho!ld be completed by the end of 99F with a

price ta of G)9 million.

Ad Astra hopes to !n"eil two operational rockets by the end of 9)9 and 9)) at a cost of G)-9 million.

Copyriht 99; 'e!ters. All rihts reser"ed.This material may not be p!blished, broadcast, rewritten, or redistrib!ted.

,A detectives delvin$ into eandert#al $enome

Scientists /oal is to #elp nderstand #o" #man brain evolved

*EI! /ermany (AP) -- 0.S. and /erman scientists lanc#ed a t"o-year pro+ect 1#rsday todecip#er t#e $enetic code of t#e eandert#al! a feat t#ey #ope "ill #elp deepen nderstandin$ of#o" modern #mans2 brains evolved.

4eanderthals were a species that li"ed in E!rope and western Asia from more than 99,999 years ao to abo!t H9,999years ao. Scientists from @ermany1s 3a# Planck $nstit!te for E"ol!tionary Anthropoloy are teamin !p with acompany in Connectic!t to map the enome, or :4A code.

%The 4eanderthal is the closest relati"e to the modern h!man, and we belie"e that by se0!encin the 4eanderthal wecan learn a lot,% said 3ichael Eholm, a "ice president at

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That st!dy s!ested that 4eanderthals and h!mans split from a common ancestor a half&million years ao and backedthe theory that 4eanderthals were an e"ol!tionary dead end, not a direct ancestor of modern h!mans.

The new pro/ect will help in !nderstandin how characteristics !ni0!e to h!mans e"ol"ed and %will also identify thoseenetic chanes that enabled modern h!mans to lea"e Africa and rapidly spread aro!nd the world,% Paabo said in astatement Th!rsday.

Copyriht 99; TheAssociated Press.All rihts reser"ed.This material may not be p!blished, broadcast, rewritten, orredistrib!ted.

Findin$ t#e roots of modern #mans

,A stdy may reveal "#o "e are! "#ere "e came from

By 3arsha 2altonC44

(C) -- 3/eno$rap#ic3 is not s#o"in$ p in many dictionaries yet. *t t"o $lobal instittions! I*M

and t#e ational /eo$rap#ic Society! #ope t#e idea it conveys becomes "ell %no"n in every cornerof t#e planet.

The @enoraphic Pro/ect, la!nchin 2ednesday, is a fi"e&year enetic anthropoloy st!dy desined to chart themiratory history of h!mans, and help fill in the blanks of how and where people mo"ed to pop!late the planet.

Pop!lation eneticist :r. Spencer 2ells, an e#plorer&in&residence at the 4ational @eoraphic Society, is director of thepro/ect.

%@enetics, $ think, reso!ndinly has answered the 0!estion of where we !ltimately came from, we came o!t of Africa.And we came o!t 0!ite recently, within the last -9 or ;9 tho!sand years,% 2ells said.

%B!t the 0!estion of how we mirated aro!nd the planet, how we pop!lated the world, in effect, is still an open one.%

2ells has spent the past )- years st!dyin pop!lation miration, atherin abo!t )9,999 samples from aro!nd theworld.

B!t he says people today mo"e faster and farther from their roots than e"er before, complicatin the /ob of scientistsand in effect %bl!rrin the family tree.%

%And the oal is to sample :4A from people all o"er the world, both indieno!s pop!lations and the eneral p!blic,%2ells said.

%2e want e"erybody to ha"e a chance to participate in this, beca!se it is really the story of all of !s, that1s what we aretryin to fi!re o!t.%

$B3 is in"ol"ed in processin the massi"e amo!nts of data that will be enerated when scientists aro!nd he world

bein atherin :4A cheek swabs and blood samples.

:r. A/ay 'oyy!r!, senior manaer for the Comp!tational Bioloy Center at $B31s 2atson 'esearch Center in 4ew Iork,e#plains the pairin of %enome% and %eoraphy.%

%The enome we all carry is the best record. $t act!ally carries the information of each of o!r ancestors. And as we!nco"er the markers in the enome, we are able to tell, who yo!r ancestors were and where they possibly come from,%he said.

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Critical to the st!dy will be :4A samples from indieno!s people, distincti"e and !ni0!e pop!lations who ha"e loninhabited certain eoraphic areas.

'oyy!r! says it is important that scientists from the beinnin approach these people, many in remote areas, with care.

%The participation of indi"id!als, in any e#ercise, re0!ires that yo! respect who they are, what they are, and the reasonwhy yo! want them to participate. And yo! make s!re that what yo! i"e them back is of "al!e to them, which is e#actly

what we are tryin to do with the indieno!s pop!lations and the p!blic at lare,% 'oyy!r! said.

The st!dy is also co!ntin on people aro!nd the world who ha"e a keen interest in their own ancestors to take part.

3illions of people are !sin the $nternet to connect with relati"es aro!nd the world, !sin a "ariety of enealoyprorams.

The @enoraphic Pro/ect co!ld take that a step farther, addin :4A details to the a"ailable information.

Those interested will ha"e to make a serio!s in"estment, G++.+- pl!s shippin and handlin, for a %participation kit.% $tincl!des a :5: and broch!res detailin the fi"e&year lobal st!dy, pl!s a cheek swab kit that indi"id!als send back tothe st!dy with their own :4A.

Pro/ect officials say these tests will be stored anonymo!sly, b!t indi"id!als will be able to track details abo!t themsel"es!sin a n!mber assined to each kit.

%Io! will be able to see, for e#ample, riht off the bat if yo! are in a partic!lar enotypic ro!p, and where is thepop!lation of that partic!lar enotypic ro!p in the world today, and what we think are the ways in which this pop!lationended !p in this location in the world. And as this data rows, we will be able to make this map, and this /o!rney andthis detail richer in content,% 'oyy!r! said.

2ells says the pro/ect has assembled a %dream team% of scientists, from 3oscow to ohannesb!r to Adelaide to Parisand Beir!t.

Besides the pop!lation e#perts, scientists from many other disciplines will be addin conte#t to the :4A information.(ne researcher will foc!s on ancient :4A, st!dyin skeletons h!ndreds, e"en tho!sands of years old.

%So what we can answer >as eneticists? is 0!estions abo!t bioloy, abo!t bioloical ancestry. B!t to make any sense ofthat historically we ha"e to conte#t!alize it && the archaeoloy, the lin!istic pattern, e"en the climatoloy,% 2ells said.

%So it really is a synthetic effort to !nderstand o!r common past.%

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