Cookie consent

AstroBin saves small pieces of text information (cookies) on your device in order to deliver better content and for statistical purposes. You can disable the usage of cookies by changing the settings of your browser. By browsing AstroBin without changing the browser settings, you grant us permission to store that information on your device.

I agree
Contains:  NGC 6939, NGC 6946
Getting plate-solving status, please wait...
Pair of NGC6939 & NGC6946, 



    
        

            Sergiy_Vakulenko
Pair of NGC6939 & NGC6946
Powered byPixInsight

Pair of NGC6939 & NGC6946

Technical card


Dates:Aug. 31, 2018

Frames:
Baader Blue 36 mm: 40x300" bin 1x1
Baader Green 36 mm: 30x300" bin 1x1
Baader Luminance 36 mm: 60x300" bin 1x1
Baader Red 36 mm: 30x300" bin 1x1

Integration: 13.3 hours

Avg. Moon age: 19.49 days

Avg. Moon phase: 76.76%


Basic astrometry details

Astrometry.net job: 2924249

RA center: 20h 33' 17"

DEC center: +60° 24' 14"

Pixel scale: 2.137 arcsec/pixel

Orientation: 355.655 degrees

Field radius: 0.927 degrees


Resolution: 2400x2000

Locations: Remote observatory, Kiev, Ukraine

Data source: Own remote observatory

Remote source: Non-commercial independent facility

Description

NGC 6946 also known as the Fireworks Galaxy is a face-on intermediate spiral galaxy with a small bright nucleus, whose location in the sky straddles the boundary between the northern constellations of Cepheus and Cygnus. Its distance from Earth is about 25.2 million light-years, similar to the distance of M101 (NGC 5457). Both were once considered to be part of the Local Group, but are now known to be among the dozen bright spiral galaxies near the Milky Way but beyond the confines of the Local Group. NGC 6946 lies within the Virgo Supercluster.

Discovered by William Herschel on 9 September 1798, this well-studied galaxy has a diameter of approximately 40,000 light-years, about one-third of the Milky Way's size, and it contains roughly half the number of stars as the Milky Way. The galaxy is heavily obscured by interstellar matter as it lies quite close to the galactic plane of the Milky Way. Due to its prodigious star formation it has been classified as an active starburst galaxy.

Various unusual celestial objects have been observed within NGC 6964. This includes the so-called 'Red Ellipse' along one of the northern arms that looks like a super-bubble or very large supernova remnant, and which may have been formed by an open cluster containing massive stars. There are also two regions of unusual dark lanes of nebulosity, while within the spiral arms several regions appear devoid of stars and gaseous hydrogen, some spanning up to two kiloparsecs across. A third peculiar object, discovered in 1967, is now known as "Hodge's Complex". This was once thought to be a young supergiant cluster, but in 2017 it was conjectured to be an interacting dwarf galaxy superimposed on NGC 6964.

Ten supernovae have been observed in NGC 6946 in the last century: SN 1917A, SN 1939C, SN 1948B, SN 1968D, SN 1969P, SN 1980K, SN 2002hh, SN 2004et, SN 2008S, and SN 2017eaw. For this reason NGC 6946 in 2005 was dubbed the "Fireworks Galaxy", a name becoming increasingly popular. NGC 6946 has an unusually high rate of supernovae production compared to our Milky Way galaxy, whose rate averages just one supernova event per century. This is the more remarkable as our Galaxy comprises twice as many stars.

NGC 6939 is an open cluster in the constellation Cepheus. It was discovered by William Herschel in 1798. The cluster lies 2/3° northwest from the spiral galaxy NGC 6946. The cluster lies approximately 4.000 light years away and it is over a billion years old.

Comments

Author

Sergiy_Vakulenko
Sergiy_Vakulenko
License: Attribution Creative Commons
911
Like

Sky plot

Sky plot

Histogram

Pair of NGC6939 & NGC6946, 



    
        

            Sergiy_Vakulenko