A team of astronomers, including Carnegie's Benjamin Shappee, Nidia Morrell, and Ian Thompson, has discovered the most-luminous supernova ever observed, called ASAS-SN-15lh. Their findings are published in Science. Supernovae are violent stellar explosions and some of the brightest objects in the universe. Human records noting their existence date back nearly 2,000 years. Within the past two decades a rare new category of super-luminous supernovae have been discovered, which shine one hundred to a thousand times brighter than themore-common supernovae. It has been theorized that these super-luminous supernovae are powered by so-called magnetars, neutron stars with extremely powerful magnetic fields, with the magnetism providing the engine for theimmense luminosity. According to this theory, the magnetic field's spin magnifies the energy of the explosion, increasing the luminosity.
As counterintuitive as it may sound, super-luminous supernovae are difficult for astronomers to spot. This is because they are rare and tend to form inlow-luminosity galaxies with vigorous star formation, whereas the sky surveysthat have been traditionally used to locate supernovae target bright galaxieswith low rates of star formation.
Thenewly found super-luminous supernova was discovered by the All Sky AutomatedSurvey for SuperNovae team (ASAS-SN), an international collaborationheadquartered at the Ohio State University, which uses a network of14-centimeter telescopes around the world to scan the visible sky every two orthree nights looking for very bright supernovae. The only all-sky variabilitysurvey in existence, it is capable of finding normal supernovae out to about 350 million light years from Earth.
"On June 14 of this year, we spotted a newly occurring explosion in a galaxy of an unknown distance," Shappee said. "Subsequent observations--includingthose made at our Las Campanas Observatory by Nidia Morrell and Ian Thompson--allowed the team to confirm the existence of the supernova ASAS-SN-15lh."
The supernova's spectra matched that of other hydrogen-poor super-luminous supernovae. But it wasn't until further follow-up was conducted that the study's lead author Subo Dong of the Kavli Institute for Astronomy and Astrophysics (KIAA) at Peking University and the rest of the team realized how unusual the supernova is. Itis two times more luminous than any supernova previously discovered. In fact,ASAS-SN-15lh at peak was almost 50 times more luminous than the entire Milky Way galaxy.
"When the first du Pont spectrum was available, as usual, I quickly checked what kind of supernova it was. To my surprise, I was not able to even tell for sure it was a supernova. My first reaction was: 'this is interesting, we should get more data,'" Morrell said. "It was only when we obtained higher resolution spectra from the Southern African Large Telescope and the Magellan Clay Telescope that I realized how distant the host galaxy is and consequently,how luminous the supernova."
1 astronomers
n.天文学者，天文学家(astronomer的名词复数 )
参考例句：
• Astronomers can accurately foretell thedate,time,and length of future eclipses. 天文学家能精确地预告未来日食月食的日期、时刻和时长。 来自《简明英汉词典》
• Astronomers used to ask why only Saturnhas rings. 天文学家们过去一直感到奇怪，为什么只有土星有光环。来自《简明英汉词典》
2 luminous
adj.发光的，发亮的；光明的；明白易懂的；有启发的
参考例句：
• There are luminous knobs on all the doorsin my house.我家所有门上都安有夜光把手。
• Most clocks and watches in this shop arein luminous paint.这家商店出售的大多数钟表都涂了发光漆。
3 neutron
n.中子
参考例句：
• Neutron is neutral and slightly heavierthan the proton.中子是中性的，比质子略重。
• Based on the neutron energy,the value ofweighting factor was given.根据中子能量给出了相应的辐射权重因子的数值。
4 magnetism
n.磁性，吸引力，磁学
参考例句：
• We know about magnetism by the waymagnets act.我们通过磁铁的作用知道磁性是怎么一回事。
• His success showed his magnetism ofcourage and devotion.他的成功表现了他的胆量和热诚的魅力。
5 galaxies
星系( galaxy的名词复数 )； 银河系； 一群（杰出或著名的人物）
参考例句：
• Quasars are the highly energetic cores ofdistant galaxies. 类星体是遥远星系的极为活跃的核心体。
• We still don't know how many galaxiesthere are in the universe. 我们还不知道宇宙中有多少个星系。
6 automated
a.自动化的
参考例句：
• The entire manufacturing process has beenautomated. 整个生产过程已自动化。
• Automated Highway System (AHS) isrecently regarded as one subsystem of Intelligent Transport System (ITS). 近年来自动公路系统(AutomatedHighway System,AHS)，作为智能运输系统的子系统之一越来越受到重视。
7 collaboration
n.合作，协作；勾结
参考例句：
• The two companies are working in closecollaboration each other.这两家公司密切合作。
• He was shot for collaboration with the enemy.他因通敌而被枪毙了。
8 spotted
adj.有斑点的，斑纹的，弄污了的
参考例句：
• The milkman selected the spottedcows,from among a herd of two hundred.牛奶商从一群200头牛中选出有斑点的牛。
• Sam's shop stocks short spotted socks.山姆的商店屯积了有斑点的短袜。
9 galaxy
n.星系；银河系；一群(杰出或著名的人物)
参考例句：
• The earth is one of the planets in theGalaxy.地球是银河系中的星球之一。
• The company has a galaxy of talent.该公司拥有一批优秀的人才。
10 observatory
n.天文台，气象台，瞭望台，观测台
参考例句：
• Guy's house was close to the observatory.盖伊的房子离天文台很近。
• Officials from Greenwich Observatory havethe clock checked twice a day.格林威治天文台的职员们每天对大钟检查两次。
11 spectra
n.光谱
参考例句：
• The infra-red spectra of quinones presenta number of interesting features. 醌类的红外光谱具有一些有趣的性质。
• This relation between the frequency andthe field spectra was noted experimentally. 实验上已经发现频率和场频谱之间的这种关系。
12 previously
adv.以前，先前（地）
参考例句：
• The bicycle tyre blew out at a previouslydamaged point.自行车胎在以前损坏过的地方又爆开了。
• Let me digress for a moment and explainwhat had happened previously.让我岔开一会儿，解释原先发生了什么。
13 milky
adj.牛奶的，多奶的；乳白色的
参考例句：
• Alexander always has milky coffee atlunchtime.亚历山大总是在午餐时喝掺奶的咖啡。
• I like a hot milky drink at bedtime.我喜欢睡前喝杯热奶饮料。
14 spectrum
n.谱，光谱，频谱；范围，幅度，系列
参考例句：
• This is a kind of atomic spectrum.这是一种原子光谱。
• We have known much of the constitution ofthe solar spectrum.关于太阳光谱的构成，我们已了解不少。
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