星系

The galaxy known as NGC 5907 stretches wide across this image. Appearing as an elongated line of stars and dark dust, the galaxy is categorized as a spiral galaxy just like our own Milky Way. In this new image from the NASA/ESA Hubble Space Telescope, we don’t see the beautiful spiral arms because we are viewing it edge-on, like looking at the rim of a plate. It is for this reason that NGC 5907 is also known as the Knife Edge galaxy. The Knife Edge galaxy is about 50 million light-years from Earth, lying in the northern constellation of Draco. Although not visible in this image, ghostly streams of stars on large arching loops extend into space, circling around the galaxy; they are believed to…

Seen here in incredible detail, thanks to the NASA/ESA Hubble Space Telescope, is the starburst galaxy formally known as PLCK G045.1+61.1. The galaxy, which appears as multiple reddish dots near the center of the image, is being gravitationally lensed by a cluster of closer galaxies, also seen in the image. Gravitational lensing occurs when a large distribution of matter, such as a galaxy cluster, sits between Earth and a distant light source. As space is warped by massive objects, the light from the distant object bends as it travels to us, creating stretched, magnified and sometimes multiple images of the lensed object. This effect was first predicted by Einstein’s general theory of relativity. From 2009 to 2013, the European Space Agency’s Planck space observatory captured…

Looking deep into the universe, the NASA/ESA Hubble Space Telescope catches a passing glimpse of the numerous arm-like structures that sweep around this barred spiral galaxy, known as NGC 2608. Appearing as a slightly stretched, smaller version of our Milky Way, the peppered blue and red spiral arms are anchored together by the prominent horizontal central bar of the galaxy. In Hubble photos like this, bright foreground stars in the Milky Way will sometimes appear as pinpoints of light with prominent light flares known as diffraction spikes, an effect of the telescope optics. A star with these features is seen in the lower right corner of the image, and another can be spotted just above the pale center of the galaxy. The majority of the…

This remarkable spiral galaxy, known as NGC 4651, may look serene and peaceful as it swirls in the vast, silent emptiness of space, but don’t be fooled — it keeps a violent secret. It is believed that this galaxy consumed another smaller galaxy to become the large and beautiful spiral that we observe today. Although only a telescope like the NASA/ESA Hubble Space Telescope, which captured this image, could give us a picture this clear, NGC 4651 can also be observed with an amateur telescope — so if you have a telescope at home and a star-gazing eye, look out for this glittering carnivorous spiral. Text credit: ESA (European Space Agency) Image credit: ESA/Hubble & NASA, D. Leonard 这个引人注目的螺旋星系，即NGC 4651，当它在广袤、寂静的太空中旋转时，看起来像宁静祥和，但不要被愚弄了——它隐藏着一个暴烈的秘密。据信，这个星系吞噬了另一个较小的星系，形成了我们今天看到的巨大而美丽的螺旋。 尽管只有像NASA/ESA哈勃太空望远镜这样的望远镜能够捕获到这张图像，才能使我们获得清晰的照片，但是NGC 4651也可以用业余望远镜观察到——所以如果你家里有望远镜和一双观星的眼睛，留意一下这个闪闪发光的食肉螺旋。 文字来源：ESA（欧洲航天局） 图片来源：ESA/Hubble和NASA, D….

NGC 4618 was discovered on April 9, 1787, by the German-British astronomer William Herschel, who also discovered Uranus in 1781. Only a year before discovering NGC 4618, Herschel theorized that the “foggy” objects astronomers were seeing in the night sky were likely to be large star clusters located much farther away than the individual stars he could easily discern. Since Herschel proposed his theory, astronomers have come to understand that what he was seeing was a galaxy. NGC 4618, classified as a barred spiral galaxy, has the special distinction among other spiral galaxies of only having one arm rotating around the center of the galaxy. Located about 21 million light-years from our galaxy in the constellation Canes Venatici, NGC 4618 has a diameter of about…