Hemisphere:  Northern  ·  Constellation: Cepheus (Cep)  ·  Contains:  Fireworks Galaxy  ·  NGC 6939  ·  NGC 6946
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Fireworks and NGC 6939, 



    
        

            Astro-TAPAS
Fireworks and NGC 6939
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Fireworks and NGC 6939

Getting plate-solving status, please wait...
Fireworks and NGC 6939, 



    
        

            Astro-TAPAS
Fireworks and NGC 6939
Powered byPixInsight

Fireworks and NGC 6939

Acquisition details

Dates:
July 18, 2021 ·  July 19, 2021 ·  July 20, 2021 ·  July 21, 2021 ·  July 22, 2021
Frames:
Astrodon Ha 1.25 5nm: 12×900(3h) -20°C bin 1×1
Baader B 1.25'' CCD Filter: 27×300(2h 15′) bin 1×1
Baader G 1.25'' CCD Filter: 15×300(1h 15′) bin 1×1
Baader L 1.25" CCD Filter: 220×300(18h 20′) -20°C bin 1×1
Baader R 1.25'' CCD Filter: 24×300(2h) -20°C bin 1×1
Integration:
26h 50′
Darks:
35
Flats:
11
Bias:
200
Avg. Moon age:
10.75 days
Avg. Moon phase:
81.01%
Bortle Dark-Sky Scale:
2.00

Basic astrometry details

Astrometry.net job: 5468839

RA center: 20h34m02s.2

DEC center: +60°2743

Pixel scale: 1.652 arcsec/pixel

Orientation: 180.207 degrees

Field radius: 0.640 degrees

Resolution: 1916x2026

File size: 19.2 MB

Data source: Own remote observatory

Remote source: e-EyE Extremadura

Description

NGC 6946 – FireWorks GalaxyThe galaxy NGC 6946 is nothing short of spectacular. In the last century alone, NGC 6946 has experienced 10 observed supernovae, earning its nickname as the Fireworks Galaxy. In comparison, our Milky Way averages just one to two supernova events per century.We are able to marvel at NGC 6946 as it is a face-on galaxy, which means that we see the galaxy “facing” us, rather than seeing it from the side (known as edge-on). The Fireworks Galaxy is further classified as an intermediate spiral galaxy and as a starburst galaxy. The former means the structure of NGC 6946 sits between a full spiral and a barred spiral galaxy, with only a slight bar in its center, and the latter means it has an exceptionally high rate of star formation.NGC 6946 is ablaze with colorful galactic fireworks fueled by the birth and death of multitudes of brilliant, massive stars. Massive stellar giants have been ending their lives in supernova explosions throughout NGC 6946 in rapid-fire fashion for tens of millions of years. It is speculated that if just a million years of this galaxy’s history were compressed into a time-lapse movie lasting a few seconds, there would be nearly constant outbursts of light as new stars flare into view, while old ones expire in spectacular explosions. Over the past century eight supernovae have exploded in the arms of this stellar metropolis, making NGC 6946 the most prolific known galaxy for supernovae during the past 100 years. Yet, it is the ubiquitous occurrence of starbirth throughout NGC 6946 and not its supernovae that lend this galaxy its blazingly colorful appearance. For reasons not completely understood, it experiences a much higher rate of star formation than all the large galaxies in our local neighborhood. The prodigious output of stellar nurseries in this galactic neighbor eventually leads to accelerated numbers of supernova explosions. Starbirth regions exist in most galaxies, particularly in spirals, and are obvious as clouds of predominantly hydrogen gas called HII regions. These areas coalesce over millions of years to form stars. Young, hot, massive stars formed in these regions emit copious amounts of ultraviolet radiation, which strip the electrons from hydrogen atoms in which they are embedded. When these ionized hydrogen atoms re-associate with electrons they radiate in a deep red color (at a wavelength of 656.3 nanometers) as the electrons transition back to lower energy levels.NGC 6946 lies 25.2 million light-years away on the border between the constellations of Cepheus and Cygnus, and was discovered by Sir William Herschel (1738-1822) on September 9, 1798. Astronomers estimate that this galaxy contains about half as many stars as the Milky Way and it is also used as a laboratory to study and characterize the evolution of massive stars and the properties of interstellar gas. NGC 6939At the bottom left of the image, much closer to us, the open cluster NGC 6939 offers an interesting contrast, with stars with well-pronounced colors. There is a high concentration of red giants within this cluster, more than a dozen of which are variable stars.Between these two objects is a more diffuse element, called "IFN" (Integrated Flux Nebulae), which could be confused with weak cloudiness within our galaxy in this image. These are actually clouds of gas and dust in the interstellar medium, or on the periphery of the galaxy, and which are visible because of the radiation of all the surrounding stars (unlike the classic nebulae by emission or absorption which are strongly linked to a particular star or star cluster). These clouds are very tenuous and can extend over gigantic dimensions around the Milky Way. We can speak, in a pictorial way, of "galactic cirrus”. If the IFN appears in visible light, it reveals its true importance only in infrared.

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Fireworks and NGC 6939, 



    
        

            Astro-TAPAS