Hubble captured NGC 4698, a strange spiral galaxy whose stars and gas rotate at right angles, revealing clues to a chaotic past.<\/p>\n
Today\u2019s Image of the Day from the European Space Agency reveals a spiral galaxy that looks peaceful at first glance.<\/p>\n
Its sweeping arms are streaked with dark dust, while young blue stars glow across the outer disk.\u00a0<\/p>\n
Look more closely, though, and the galaxy<\/a> stops making sense.\u00a0<\/p>\n Parts of it are arranged almost at right angles to one another, and the stars and gas near its center rotate in a different direction from the main disk.\u00a0<\/p>\n Something appears to have knocked this galaxy badly out of alignment.<\/p>\n A strange galaxy in Virgo<\/p>\n The galaxy is NGC 4698, located about 55 million light-years from Earth in the constellation Virgo.\u00a0<\/p>\n It belongs to the Virgo Cluster, a huge collection of more than 1,000 galaxies held together by gravity. It is the nearest large galaxy cluster to our own cosmic neighborhood.<\/p>\n The new view comes from the NASA\/ESA Hubble Space Telescope<\/a>. At first, NGC 4698 has many of the features astronomers expect from a spiral galaxy.\u00a0<\/p>\n A thin disk contains stars, gas, and dust, while spiral arms curl around its center. In that sense, its basic structure resembles the Milky Way.<\/p>\n Spiral arms keep their distance<\/p>\n NGC 4698 becomes more unusual when its spiral pattern is examined closely.\u00a0<\/p>\n In many spiral galaxies, the arms wind inward toward the central region. Here, they are most obvious farther out, forming something closer to a ring around the galaxy.<\/p>\n Dust collects along the spiral structure, with pockets of recent star formation scattered farther from the center.<\/p>\n The center looks different. Its softer, off-white glow comes largely from smaller, cooler and older stars packed into the galactic bulge.<\/p>\n A black hole at the center<\/p>\n Those central stars orbit a supermassive black hole with a mass millions of times greater than that of the Sun.\u00a0<\/p>\n Evidence indicates that the black hole is active and still growing as its gravity pulls material inward.<\/p>\n Supermassive black holes<\/a> occupy the centers of many large galaxies, including the Milky Way.\u00a0<\/p>\n Their surroundings can reveal a great deal about a galaxy\u2019s history because gas flowing toward the center can feed the black hole while also affecting star formation nearby.<\/p>\n Parts spin at right angles<\/p>\n The real surprise in NGC 4698 is its geometry. The central bulge does not line up normally with the surrounding disk.\u00a0<\/p>\n Instead, it extends from the disk at roughly a right angle, making NGC 4698 one of only a small number of spiral galaxies known to have this configuration.<\/p>\n Hubble\u2019s image offers a faint visual clue. The glow of the elongated bulge can be seen extending above and below the dusty disk.\u00a0<\/p>\n Measurements of motion reveal an even stranger arrangement: stars and gas close to the center rotate perpendicular to the galaxy\u2019s main disk.\u00a0<\/p>\n Two parts of the same galaxy are effectively following different planes of rotation.<\/p>\n Gas arrived from elsewhere<\/p>\n Astronomers think the explanation probably involves material that came from outside NGC 4698.\u00a0<\/p>\n If the galaxy captured gas whose motion did not match that of its existing disk, the incoming material could have settled into a new plane.\u00a0<\/p>\n Stars forming from that gas would preserve the unusual orientation.<\/p>\n Galaxies frequently change through encounters with their neighbors. They can pull material from one another, capture gas, or merge entirely.\u00a0<\/p>\n Even a relatively small collision can leave structures that survive long after the encounter itself has ended.<\/p>\n A tail points to its past<\/p>\n NGC 4698 carries another possible clue to such an event. Observations have revealed a short tail of hydrogen extending from one side of the galaxy.\u00a0<\/p>\n Researchers have suggested that the feature could be evidence of a minor galactic merger<\/a> in its past.<\/p>\n That possibility is especially interesting in the Virgo Cluster. Galaxies there do not evolve in isolation.\u00a0<\/p>\n They move through a crowded environment where gravity from neighboring galaxies and interactions with gas between galaxies can reshape them.\u00a0<\/p>\n Other Virgo galaxies show distorted disks, stripped gas, and long gaseous tails produced by their surroundings.<\/p>\n Hubble studies a crowded neighborhood<\/p>\n The observations behind the new image were collected through the Hubble observing program 18103, led by principal investigator David Thilker.\u00a0<\/p>\n The program is studying Virgo Cluster galaxies closely enough to examine features such as individual star clusters and nebulae.<\/p>\n Researchers are also using those detailed observations to tackle a much larger question: how does life inside a galaxy cluster<\/a> change a galaxy over time?\u00a0<\/p>\n By studying star formation, gas, and unusual structures across nearby Virgo galaxies, astronomers can reconstruct some of that history.<\/p>\n NGC 4698 offers an especially striking case. Its calm spiral shape hides a galaxy whose inner and outer regions never quite got on the same page.\u00a0<\/p>\n Whatever happened in its past, the evidence is still written in the way its stars and gas move today.<\/p>\n Image Credit: NASA Earth Observatory<\/p>\n \u2014\u2013<\/p>\n Like what you read? Subscribe to our newsletter<\/a> for engaging articles, exclusive content, and the latest updates.\u00a0<\/p>\n Check us out on EarthSnap<\/a>, a free app brought to you by Eric Ralls<\/a> and Earth.com.<\/p>\n \u2014\u2013<\/p>\n","protected":false},"excerpt":{"rendered":"Hubble captured NGC 4698, a strange spiral galaxy whose stars and gas rotate at right angles, revealing clues…\n","protected":false},"author":2,"featured_media":899398,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[64,63,128],"class_list":["post-899397","post","type-post","status-publish","format-standard","has-post-thumbnail","category-science","tag-au","tag-australia","tag-science"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts\/899397","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/comments?post=899397"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts\/899397\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/media\/899398"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/media?parent=899397"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/categories?post=899397"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/tags?post=899397"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}