The Hubble team has released a new image snapped by the NASA/ESA Hubble Space Telescope of the barred spiral galaxy NGC 6951.
This Hubble image shows NGC 6951, a barred spiral galaxy some 78 million light-years away in the constellation of Cepheus. The color image includes both optical and infrared observations from both Hubble’s Advanced Camera for Surveys (ACS) and Wide Field Camera 3 (WFC3). Image credit: NASA / ESA / Hubble / A. Filippenko, University of California, Berkeley / R. Foley (University of California, Santa Cruz / C. Kilpatrick, Northwestern University / D. Sand, University of Arizona / Gladys Kober, NASA & Catholic University of America.
NGC 6951 is located approximately 78 million light-years away in the constellation of Cepheus.
Also catalogued as NGC 6952, the galaxy is about 75,000 light-years across, and since it is close to the northern celestial pole, it is visible from the northern hemisphere.
NGC 6951 was discovered independently by the French astronomer Jerome Coggia in 1877 and the American astronomer Lewis Swift in 1878.
“The galaxy had its highest rates of star formation about 800 million years ago, then sat quietly for 300 million years before beginning to birth stars again,” the Hubble astronomers said.
“The average age of a star cluster, or gravitationally-bound group of stars, in this galaxy is 200 to 300 million years old, though some are as old as one billion years.”
“Turbulent regions of gas, shown in dark red, surround the bright blue pinpricks that are star clusters.”
Astronomers classify NGC 6951 as a Type II Seyfert galaxy and a low-ionization nuclear emission-line region (LINER) galaxy.
“A Type II Seyfert galaxy is a type of active galaxy that emits large amounts of infrared radiation and has slow-moving gaseous matter near its center,” the researchers explained.
“LINER is similar to a Type II Seyfert galaxy but with a cooler nucleus that emits weakly ionized or neutral atoms like oxygen, nitrogen, and sulfur.”
At the center of NGC 6951 lies a supermassive black hole surrounded by a so-called circumnuclear ring.
This circumnuclear ring is 3,700 light-years across and is between 1 and 1.5 billion years old.
“Astronomers hypothesize that interstellar gas flows through the dense, starry bar of the galaxy to the circumnuclear ring, which supplies new material for star formation,” the scientists said.
“Up to 40% of the mass in the ring comes from relatively new stars that are less than 100 million years old.”
“Spiral lanes of dust, shown in dark orange, connect the center of the galaxy to its outer regions, contributing more material for future star formation.”
“Some of the stars in NGC 6951 have also experienced terrific stellar explosions known as supernovae; astronomers have counted as many as six supernovae in this galaxy in the past 25 years.”
