Astronomers have watched as a massive, dying star was likely reborn as a black hole. It took the combined power of the Large Binocular Telescope (LBT), and NASA's Hubble and Spitzer space telescopes to go looking for remnants of the vanquished star, only to find that it disappeared out of sight. Read more
Patrick Wiggins discovers supernova in Fireworks Galaxy
On May 13, 2017, Patrick Wiggins, public outreach educator for the University of Utah's Department of Physics & Astronomy, and NASA solar system ambassador to Utah, spotted something unusual in the sky. He was looking at the spiral galaxy NGC 6946, known as the Fireworks Galaxy, in the Cygnus constellation over 22 million light-years away from his telescope at his home near Erda, Utah. He noticed a bright spot that he hadn't seen before. By comparing what he was seeing with earlier photographs taken of the same galaxy, he realised he was witnessing a star explode. He had just discovered a supernova. Read more
NGC 6946 (also The Fireworks Galaxy, Arp 29, Caldwell 12, MCG 10-29-6, UGC 11597 and PGC 65001) is a magnitude ++9.6 intermediate spiral galaxy located 22.5 ±7.8 million light-years on the border of the constellations Cepheus and Cygnus.
The galaxy was discovered by German-British astronomer William Herschel using a 47.5 cm (18.7 inch) f/13 speculum reflector at Observatory House, Windsor Road, Slough, Berkshire on the 9th September 1798.
Right Ascension 20h 34m 52.3s, Declination +60° 09' 14"
NGC 6946 is highly obscured by interstellar matter of the Milky Way galaxy, as it is quite close to the galactic plane. Ten supernovae have been observed in NGC 6946 in the last 100 years: SN 1917A,SN 1939C, SN 1948B, SN 1968D, SN 1969P, SN 1980K, SN 2002hh, SN 2004et,SN 2008S, and SN 2017eaw) . Read more
River of Hydrogen Flowing through Space Seen with Green Bank Telescope
Using the National Science Foundation's Robert C. Byrd Green Bank Telescope (GBT), astronomer D.J. Pisano from West Virginia University has discovered what could be a never-before-seen river of hydrogen flowing through space. This very faint, very tenuous filament of gas is streaming into the nearby galaxy NGC 6946 and may help explain how certain spiral galaxies keep up their steady pace of star formation. Read more
Title: Spectroscopy of H II Regions in the Late-Type Spiral Galaxy NGC 6946 Authors: Alexander S. Gusev, Firouz Sakhibov, Sergey N. Dodonov
We present the results of spectroscopy of 39 H II regions in the spiral galaxy NGC 6946. The spectral observations were carried out at the 6-m BTA telescope of the SAO RAS with the SCORPIO focal reducer in the multi-slit mode with the dispersion of 2.1A/px and spectral resolution of 10A. The absorption estimates for 39 H II regions were obtained. Using the "strong line" method (NS-calibration) we determined the electron temperature, and the abundances of oxygen and nitrogen for 30 H II regions. The radial gradients of O/H and N/H were constructed.
Title: Giant molecular clouds in the non-grand design spiral galaxy NGC 6946 Authors: David Rebolledo, Tony Wong, Adam Leroy, Jin Koda, Jennifer Donovan Meyer
We present high spatial resolution observations of Giant Molecular Clouds (GMCs) in the eastern part of the nearby spiral galaxy NGC 6946 obtained with the Combined Array for Research in Millimetre-wave Astronomy (CARMA). We have observed 12CO(1-0), 12CO(2-1) and 13CO(1-0), achieving spatial resolutions of 5.4" x 5.0", 2.5" x 2.0" and 5.6" x 5.4" respectively over a region of 6 x 6 kpc. This region extends from 1.5 kpc to 8 kpc galactocentric radius, thus avoiding the intense star formation in the central kpc. We have recovered short-spacing u-v components by using single dish observations from the Nobeyama 45m and IRAM 30m telescopes. Using the automated CPROPS algorithm we identified 44 CO cloud complexes in the 12CO(1-0) map and 64 GMCs in the 12CO(2-1) maps. The sizes, line widths, and luminosities of the GMCs are similar to values found in other extragalactic studies. We have classified the clouds into on-arm and inter-arm clouds based on the stellar mass density traced by the 3.6 um map. On-arm clouds present in general higher star formation rates than clouds located on inter-arm regions. Although the star formation efficiency shows no systematic trend with galactocentric radius, some on-arm clouds -- which are more luminous and more massive compared to inter-arm GMCs -- are also forming stars more efficiently than the rest of the identified GMCs. These structures appear to be located on two specific regions in the spiral arms. One of them shows a strong gradient, suggesting that this region of high star formation efficiency may be the result of gas flow convergence.