Astronomy Picture Of The Day: Spiral Galaxy NGC 1566

 

#NASA, #Space, #astronomy, #διάστημα

Black Hole@konstructivizm

Webb and Hubble’s Views of Spiral Galaxy NGC 1566 In Hubble’s images, the galaxies’ cores are not as bright so these spikes are absent. Diffraction spikes only appear when the source is extremely bright and compact. Sometimes, the central region in Webb’s image has a blue glow. This is a marker of high concentrations of older stars. Webb’s infrared observations allow us to see through the gas and dust to identify these older stars. The light these old stars emit are some of the shortest infrared wavelengths in Webb’s images, which is why they are assigned blue. (Read more about how color is precisely applied to Webb’s images.) In comparison, the cores of Hubble’s image may appear yellower, washing the central region in a soft glow and fully obscuring individual points of light. Hazy brown dust lanes may also cover part of this area. In Hubble’s images, older stars are emitting some of the longest wavelengths of visible light Hubble captures, which is why the color assignments are different. (Compare the wavelengths of light Hubble and Webb observe.) In Webb’s image, the newly fully formed stars also appear blue along the galaxies’ spiral arms. Those blue stars have blown away the gas and dust that immediately surrounded them. The farther away they are from the core, the more likely stars are to be younger. Orange stars, likely seen in groups in these images, are even younger: They are still encased in their cocoons of gas and dust, allowing them to continue forming. In Hubble’s view, distant galaxies are often light orange if they are slightly closer. Like in Webb's image, those that are deeper red are also more distant. Galaxy NGC 1566 was observed as part of the Physics at High Angular resolution in Nearby GalaxieS (PHANGS) program, a large project that includes observations from several space- and ground-based telescopes of many galaxies to help researchers study all phases of the star formation cycle, from the formation of stars within dusty gas clouds to the energy released in the process that creates the intricate structures revealed by Webb’s new images. NGC 1566 is 60 million light-years away in the constellation Dorado. Image: NASA, ESA, CSA, STScI, PHANGS Team, Janice Lee (STScI), Thomas Williams (Oxford), Rupali Chandar (UToledo), Daniela Calzetti (UMass)