The NASA/ESA Hubble Space Telescope has taken a picture of the barred spiral galaxy NGC 1672, which is visible from the southern hemisphere.
This Hubble image shows NGC 1672, a barred spiral galaxy some 49 million light-years away in the constellation of Dorado. The color image was made from separate exposures taken in the ultraviolet, visible and near-infrared regions of the spectrum with Hubble’s Advanced Camera for Surveys (ACS) and Wide Field Camera 3 (WFC3). Six filters were used to sample various wavelengths. The color results from assigning different hues to each monochromatic image associated with an individual filter. Image credit: ESA / Hubble / NASA / O. Fox / L. Jenkins / S. Van Dyk / A. Filippenko / J. Lee / PHANGS-HST Team / D. de Martin / M. Zamani.
NGC 1672 is located around 49 million light-years away in the constellation of Dorado.
Also known as ESO 118-43, IRAS 04449-5920, LEDA 15941 or VV 826, this galaxy has a diameter of 75,000 light-years.
It was discovered by the Scottish astronomer James Dunlop on November 5, 1826.
NGC 1672 is a prototypical barred spiral galaxy and differs from normal spiral galaxies in that the spiral arms do not twist all the way into the center.
Instead, they are attached to the two ends of a straight bar of stars enclosing the nucleus.
NGC 1672 is seen almost face on and shows regions of intense star formation.
The greatest concentrations of star-forming regions are found near the ends of the galaxy’s strong galactic bar.
NGC 1672 is also classified as a Seyfert galaxy, named after the astronomer, Carl Keenan Seyfert, who studied a family of galaxies with active nuclei extensively in the 1940s. The energy output of these nuclei can sometimes outshine their host galaxies.
The active galaxy family also includes the exotically named quasars and blazars.
Although each type has distinctive characteristics, they are thought to be all driven by the same engine — supermassive black holes — but are viewed from different angles.
“NGC 1672 is a multi-talented light show, showing off an impressive array of different celestial lights,” the Hubble astronomers said in a statement.
“Like any spiral galaxy, its disk is filled with billions of shining stars that give it a beautiful glow.”
“Along its two large arms, bubbles of hydrogen gas are made to shine a striking red light by the powerful radiation of newly-forming stars within.”
“Near to the center lie some particularly spectacular stars: newly-formed and extremely hot, they are embedded in a ring of hot gas and are emitting powerful X-rays,” they added.
“And in the very center sits an even more brilliant source of X-rays, an active galactic nucleus created by the heated accretion disk around NGC 1672’s supermassive black hole; this makes NGC 1672 a Seyfert galaxy.”
“But a highlight of the new picture is the most fleeting and temporary of these lights: supernova SN 2017gax, visible in just one of the six Hubble images that make up this composite image.”
“This was a Type I supernova caused by the core-collapse and subsequent explosion of a giant star, going from invisibility to a new light in the sky in just a matter of days.”
“In that image from later that year, the supernova is already fading, and so is only just visible here as a small green dot, just below the crook of the spiral arm on the right side.”
“In fact this was on purpose, as we wanted to look for any companion star that the supernova progenitor may have had — something impossible to spot beside a live supernova.”
Source : Breaking Science News