我們剛剛得到銀河系年齡的最新估計

我們剛剛得到銀河系年齡的最新估計

Like many other spiral galaxies in the Universe, the Milky Way Galaxy consists of two disk-like structures – the thin disk and the thick disk. The thick disk, which envelopes the thin disk, contains about 20 percent of the Milky Way's stars and is thought to be the older of the pair based on the composition of its stars (which have greater metallicity) and its puffier nature.

像宇宙中許多其他螺旋星系一樣，銀河系由兩個盤狀結構組成——薄圓盤和厚圓盤。這個厚厚的圓盤包裹著這個薄薄的圓盤，它包含了銀河系大約20%的恒星，根據(jù)它的恒星組成(有更大的金屬豐度)和膨脹的性質，它被認為是這對恒星中較老的一個。

However, in a recent study, a team of 38 scientists led by researchers from Australia's ARC Centre of Excellence for All Sky Astrophysics in Three Dimensions (ASTRO-3D) used data from the now-retired Kepler mission to measure starquakes in the Milky Way's disk.

然而，在最近的一項研究中，一個由澳大利亞ARC卓越中心(ARC Centre of Excellence for All Sky Astrophysics in Three - Dimensions)的研究人員領導的38名科學家組成的團隊，使用了現(xiàn)已退役的開普勒(Kepler)任務的數(shù)據(jù)來測量銀河系圓盤上的星震。

From this, they have revised the official estimates on the age of the Milky Way's thick disk, which they conclude is around 10 billion years old.

據(jù)此，他們修正了官方對銀河系厚盤年齡的估計，他們得出的結論是它大約有100億年的歷史。

The study which describes their findings – titled "The K2-HERMES Survey: age and metallicity of the thick disc" – recently appeared in the Monthly Notices of the Royal Astronomical Society. The research team was led by Dr. Sanjib Sharma of the Sydney Institute for Astronomy and the ARC Centre of Excellence for All Sky Astrophysics in Three Dimensions (ASTRO-3D) and included members from multiple universities and research institutes.

這項研究描述了他們的發(fā)現(xiàn)——標題為“k2 -赫爾墨斯調查:厚盤的年齡和金屬豐度”——最近發(fā)表在《皇家天文學會月刊》上。該研究小組由悉尼天文研究所和ARC三維天體物理學卓越中心的Sanjib Sharma博士領導，成員來自多個大學和研究機構。

To determine the age of the thick disk, Dr. Sharma and his team employed a method known as asteroseismology. This consists of measuring a star's oscillations caused by starquakes, where the crusts of stars undergo sudden shifts similar to Earthquakes.

為了確定厚圓盤的年齡，Sharma博士和他的團隊采用了一種被稱為星震學的方法。這包括測量由恒星地震引起的恒星振動，恒星的外殼經歷類似于地震的突然轉變。

This process allows researchers to conduct "galactic-archaeology", where they are able to look back in time to the formation of the Milky Way (over 13 billion years ago).

這個過程使研究人員能夠進行“銀河考古學”，在那里他們能夠回顧銀河系形成的時間(超過130億年前)。

As Dennis Stello – an associate professor at the University of New South Wales and a co-author on the study – explained, this allowed them to determine a star's internal structures:

正如新南威爾士大學副教授、該研究的合著者丹尼斯·斯泰羅解釋的那樣，這使得他們能夠確定恒星的內部結構:

The quakes generate soundwaves inside the stars that make them ring, or vibrate. The frequencies produced tell us things about the stars' internal properties, including their age. It's a bit like identifying a violin as a Stradivarius by listening to the sound it makes.

“地震在恒星內部產生聲波，使它們發(fā)出聲音，或者振動。產生的頻率告訴我們恒星的內部屬性，包括它們的年齡。這有點像通過聽小提琴發(fā)出的聲音來辨別它是不是斯特拉迪瓦里琴。”

It is important to note that astronomers are not able to detect actual "sounds" generated by stars. Instead, movements within a star's interior are measured based on changes in a star's brightness.

需要注意的是，天文學家無法探測到恒星發(fā)出的實際“聲音”。相反，恒星內部的運動是根據(jù)恒星亮度的變化來測量的。