Hubble Portrays a Dusty Spiral Galaxy
The NASA/ESA Hubble Space Telescope has provided us with another outstanding image of a nearby galaxy. This week, we highlight the galaxy NGC 4183, seen here with a beautiful backdrop of distant galaxies and nearby stars. Located about 55 million light-years from the sun and spanning about eighty thousand light-years, NGC 4183 is a little smaller than the Milky Way. This galaxy, which belongs to the Ursa Major Group, lies in the northern constellation of Canes Venatici (The Hunting Dogs).
NGC 4183 is a spiral galaxy with a faint core and an open spiral structure. Unfortunately, this galaxy is viewed edge-on from the Earth, and we cannot fully appreciate its spiral arms. But we can admire its galactic disk.
The disks of galaxies are mainly composed of gas, dust and stars. There is evidence of dust over the galactic plane, visible as dark intricate filaments that block the visible light from the core of the galaxy. In addition, recent studies suggest that this galaxy may have a bar structure. Galactic bars are thought to act as a mechanism that channels gas from the spiral arms to the center, enhancing star formation, which is typically more pronounced in the spiral arms than in the bulge of the galaxy.
British astronomer William Herschel first observed NGC 4183 on 14 January 1778.
This picture was created from visible and infrared images taken with the Wide Field Channel of the Advanced Camera for Surveys. The field of view is approximately 3.4 arcminutes wide.
This image uses data identified by Luca Limatola in the Hubble's Hidden Treasures image processing competition.
Hubble Catches Glowing Gas and Dark Dust in a Side-On Spiral
The NASA/ESA Hubble Space Telescope has produced a sharp image of NGC 4634, a spiral galaxy seen exactly side-on. Its disk is slightly warped by ongoing interactions with a nearby galaxy, and it is crisscrossed by clearly defined dust lanes and bright nebulae.
NGC 4634, which lies around 70 million light-years from Earth in the constellation of Coma Berenices, is one of a pair of interacting galaxies. Its neighbor, NGC 4633, lies just outside the upper right corner of the frame, and is visible in wide-field views of the galaxy. While it may be out of sight, it is not out of mind: its subtle effects on NGC 4634 are easy to see to a well-trained eye.
Gravitational interactions pull the neat spiral forms of galaxies out of shape as they get closer to each other, and the disruption to gas clouds triggers vigorous episodes of star formation. While this galaxy’s spiral pattern is not directly visible thanks to our side-on perspective, its disk is slightly warped, and there is clear evidence of star formation.
Along the full length of the galaxy, and scattered around parts of its halo, are bright pink nebulae. Similar to the Orion Nebula in the Milky Way, these are clouds of gas that are gradually coalescing into stars. The powerful radiation from the stars excites the gas and makes it light up, much like a fluorescent sign. The large number of these star formation regions is a telltale sign of gravitational interaction.
The dark filamentary structures that are scattered along the length of the galaxy are caused by cold interstellar dust blocking some of the starlight.
Hubble’s image is a combination of exposures in visible light produced by Hubble’s Advanced Camera for Surveys and the Wide Field and Planetary Camera 2.
"These are the things to keep in mind. These are not just academic exercises. We're not analyzing the media on Mars or in the eighteenth century or something like that. We're dealing with real human beings who are suffering and dying and being tortured and starving because of policies that we are involved in, we as citizens of democratic societies are directly involved in and are responsible for, and what the media are doing is ensuring that we do not act on our responsibilities, and that the interests of power are served, not the needs of the suffering people, and not even the needs of the American people who would be horrified if they realized the blood that's dripping from their hands because of the way they are allowing themselves to be deluded and manipulated by the system."
Jesus didn’t say yes to everyone. I mean Jesus knew that there was a place for everything and it is not necessarily everyone’s place to come to Australia
Tony Abbott......Current Australian PM