0
Astronomers using the Gemini North telescope have captured this vivid image of the strangely lopsided spiral galaxy NGC 772.
The overdeveloped spiral arm of the galaxy NGC 772 dominates this image from the Gemini North telescope. Image credit: Gemini Observatory / NOIRLab / NSF / AURA / T.A. Rector, University of Alaska Anchorage / J. Miller, Gemini Observatory & NSF’s NOIRLab / M. Zamani / D. de Martin.
NGC 772 resides approximately 116 million light-years away in the constellation of Aries.
Also known as LEDA 7525, UGC 1466 and Arp 78, this galaxy has a diameter of 200,000 light-years.
First discovered on November 29, 1785 by the German-born British astronomer William Herschel, NGC 772 is both a peculiar and an unbarred spiral galaxy.
The new image from the Gemini North telescope in Hawai’i, one half of the international Gemini Observatory, shows NGC 772’s overdeveloped spiral arm, which stretches across toward the left-hand edge of the frame,” the astronomers said.
“This extra large arm is due to one of NGC 772’s unruly neighbors, the dwarf elliptical galaxy NGC 770.”
“The tidal interactions between NGC 772 and its diminutive companion have distorted and stretched one of the spiral galaxy’s arms, giving it the lopsided appearance seen in this image.”
“NGC 772 also lacks a bright central bar,” the researchers added.
“Other spiral galaxies such as the Andromeda Galaxy or our own Milky Way exhibit prominent central bars — large, linear structures composed of gas, dust, and countless stars.”
“Without a bar, NGC 772’s spiral arms sweep out directly from the bright center of the galaxy.”
Astronomer Halton Arp included NGC 772 in his Atlas of Peculiar Galaxies as Arp 78, where it is described as a ‘spiral galaxy with a small high-surface brightness companion.’
“The galaxy’s unusual appearance has earned it the distinction of appearing in the Atlas of Peculiar Galaxies, a careful curation by Halton Arp of some of the weird and wonderful galaxies populating the Universe,” the scientists said.
“The 338 galaxies in the Atlas are a rogues’ gallery of strange and unusual galaxy shapes chosen to provide astronomers with a catalog of odd galaxy structures.”
“Entries in the Atlas of Peculiar Galaxies include galaxies boasting trailing tidal tails, rings, jets, detached segments, and a host of other structural idiosyncrasies. NGC 772 is included as Arp 78.”
“While NGC 772’s peculiarities dominate this image, there is also a menagerie of galaxies lurking in the background,” they added.
“The bright smears and smudges littering this image are distant galaxies — some of the closer examples can be resolved into characteristic spiral shapes.”
“Every direction on the sky that astronomers have pointed telescopes toward contains a rich carpet of galaxies, with an estimated 2 trillion galaxies in total in our observable Universe.”
Source link: https://www.sci.news/astronomy/gemini-ngc-772s-overdeveloped-spiral-arm-10643.html
Source link: https://vietnet.org/gemini-focuses-on-ngc-772s-overdeveloped-spiral-arm/
