"/>

无码少妇一区二区三区免费,妓院一钑片免看黄大片,国语自产视频在线,亚洲AV成人无码国产一区二区,激情久久综合精品久久人妻,日韩免费毛片,综合成人亚洲网友偷自拍,国内自拍视频在线观看,欧美熟妇性xxxx交潮喷,国产成人精品一区二免费网站

Second nearest star system may be "habitable" in terms of X-ray radiation: study

Source: Xinhua    2018-06-07 04:01:38

WASHINGTON, June 6 (Xinhua) -- A new study involving monitoring of nearest stars beyond our Sun revealed that one of them might be friendlier to life than the Sun in terms of X-ray radiation.

The United States space agency NASA said on Wednesday in a news release that any planets orbiting the two brightest stars in the Alpha Centaur system were likely not being pummeled by large amounts of X-ray radiation from their host stars.

Alpha Centauri is a triple star system located just over four light years, or about 40 trillion kilometers, from the Earth.

"Because it is relatively close, the Alpha Centauri system is seen by many as the best candidate to explore for signs of life," said Tom Ayres with the University of Colorado Boulder.

"The question is, will we find planets in an environment conducive to life as we know it?" said Ayres.

X-rays and related space weather effects are bad for unprotected life, directly through high radiation doses and indirectly through stripping away planetary atmospheres.

The stars in the Alpha Centauri system include a pair called "A" and "B," which orbit relatively close to each other.

Alpha Cen A is a near twin of our Sun in almost every way, including age, while Alpha Cen B is somewhat smaller and dimmer but still quite similar to the Sun.

The third member, Alpha Cen C, also known as Proxima, is a much smaller red dwarf star that travels around the AB pair in a much larger orbit that takes it more than 10,000 times farther from the AB pair than the Earth-Sun distance.

Proxima currently holds the title of the nearest star to Earth, and AB is a very close second, according to NASA.

The Chandra data revealed that the prospects for life in terms of current X-ray bombardment were actually better around Alpha Cen A than for the Sun, and Alpha Cen B fares only slightly worse.

Proxima, on the other hand, is a type of active red dwarf star known to frequently send out dangerous flares of X-ray radiation, and is likely hostile to life, according to NASA.

The findings came after more than a decade observation by NASA's Chandra X-ray Observatory.

"This is very good news for Alpha Cen AB in terms of the ability of possible life on any of their planets to survive radiation bouts from the stars," said Ayres. "Chandra shows us that life should have a fighting chance on planets around either of these stars."

However, the bad news is that, although there is one remarkable Earth-size planet around Proxima, astronomers have till now failed to find exoplanets around Alpha Cen A and B.

Planet-hunting around these stars has proved more difficult recently due to the orbit of the pair, which has drawn the two bright stars close together on the sky over the past decade.

Planets in the habitable zone around Proxima receive an average dose of X-rays about 500 times larger than the Earth, and 50,000 times larger during a big flare, according to NASA.

Editor: yan
Related News
Xinhuanet

Second nearest star system may be "habitable" in terms of X-ray radiation: study

Source: Xinhua 2018-06-07 04:01:38

WASHINGTON, June 6 (Xinhua) -- A new study involving monitoring of nearest stars beyond our Sun revealed that one of them might be friendlier to life than the Sun in terms of X-ray radiation.

The United States space agency NASA said on Wednesday in a news release that any planets orbiting the two brightest stars in the Alpha Centaur system were likely not being pummeled by large amounts of X-ray radiation from their host stars.

Alpha Centauri is a triple star system located just over four light years, or about 40 trillion kilometers, from the Earth.

"Because it is relatively close, the Alpha Centauri system is seen by many as the best candidate to explore for signs of life," said Tom Ayres with the University of Colorado Boulder.

"The question is, will we find planets in an environment conducive to life as we know it?" said Ayres.

X-rays and related space weather effects are bad for unprotected life, directly through high radiation doses and indirectly through stripping away planetary atmospheres.

The stars in the Alpha Centauri system include a pair called "A" and "B," which orbit relatively close to each other.

Alpha Cen A is a near twin of our Sun in almost every way, including age, while Alpha Cen B is somewhat smaller and dimmer but still quite similar to the Sun.

The third member, Alpha Cen C, also known as Proxima, is a much smaller red dwarf star that travels around the AB pair in a much larger orbit that takes it more than 10,000 times farther from the AB pair than the Earth-Sun distance.

Proxima currently holds the title of the nearest star to Earth, and AB is a very close second, according to NASA.

The Chandra data revealed that the prospects for life in terms of current X-ray bombardment were actually better around Alpha Cen A than for the Sun, and Alpha Cen B fares only slightly worse.

Proxima, on the other hand, is a type of active red dwarf star known to frequently send out dangerous flares of X-ray radiation, and is likely hostile to life, according to NASA.

The findings came after more than a decade observation by NASA's Chandra X-ray Observatory.

"This is very good news for Alpha Cen AB in terms of the ability of possible life on any of their planets to survive radiation bouts from the stars," said Ayres. "Chandra shows us that life should have a fighting chance on planets around either of these stars."

However, the bad news is that, although there is one remarkable Earth-size planet around Proxima, astronomers have till now failed to find exoplanets around Alpha Cen A and B.

Planet-hunting around these stars has proved more difficult recently due to the orbit of the pair, which has drawn the two bright stars close together on the sky over the past decade.

Planets in the habitable zone around Proxima receive an average dose of X-rays about 500 times larger than the Earth, and 50,000 times larger during a big flare, according to NASA.

[Editor: huaxia]
010020070750000000000000011105521372356741
国产偷窥熟女精品视频大全 | 亚洲国产精品高清久久久| 亚洲AV日韩专区在线观看| 久久男人av资源网站无码| 国产互换人妻hd| 国产亚洲欧洲aⅴ综合一区| 久久亚洲AV无码精品色午夜麻| 精品国产午夜理论片不卡精品| 国产亚洲色婷婷久久99精品| 国产午夜精品在人线播放| 亚洲国产成人综合熟女| 亚洲综合一区二区三区| 亚洲丰满熟女一区二区蜜桃| 三区在线视频| 久久国产伦子伦精品| 成年网站未满十八禁视频天堂| 亚洲欧美一区二区不卡精品| 亚洲熟妇AV午夜无码不卡| 黄色三级亚洲男人的天堂| 夜色资源站国产www在线视频 | 狠狠精品久久久无码中文字幕| 日韩精品一区二区三区中文| 竹菊影视欧美日韩一区二区三区四区五区| 成年女人碰碰碰视频播放 | 精品人妻码一区二区三区| 成全免费高清动漫电影| 4399理论片午午伦夜理片| 亚洲日本视频一区二区三区| 国产精品久久久国产盗摄| 香港日本三级亚洲三级| 精品视频在线观看免费无码| 亚洲av综合色区手机| 中文字幕人妻无码一区二区三区| 97久久久精品综合88久久| 久久av无码精品人妻出轨| 精品无码国产自产拍在线观看| 国产91色在线精品三级| 波多野结衣中文字幕一区| 国产精品成年片在线观看| 日本一区二区三区四区黄色| 亚洲产国偷v产偷v自拍色戒|