Hemisphere:  Northern  ·  Constellation: Draco (Dra)  ·  Contains:  NGC 5976  ·  NGC 5981  ·  NGC 5982  ·  NGC 5985
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Draco Triplet • NGC 5985, 5982 & 5981, 



    
        

            Douglas J Struble
Draco Triplet • NGC 5985, 5982 & 5981
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Draco Triplet • NGC 5985, 5982 & 5981

Getting plate-solving status, please wait...
Draco Triplet • NGC 5985, 5982 & 5981, 



    
        

            Douglas J Struble
Draco Triplet • NGC 5985, 5982 & 5981
Powered byPixInsight

Draco Triplet • NGC 5985, 5982 & 5981

Technical card

Imaging telescopes or lenses: Explore Scientific 152 mm Carbon Fiber

Imaging cameras: ZWO ASI1600MM-PRO

Mounts: Astro-Physics Mach 1 GTO

Guiding telescopes or lenses: Orion 80mm Short Tube

Guiding cameras: Starlight Xpress Lodestar x2

Software: PHD2  ·  Sequence Generator Pro  ·  PixInsight  ·  Photoshop CS5  ·  SkySafari Pro

Filters: Astrodon Lum Tru-Balance E-Series Gen 2  ·  Astrodon Green Tru-Balance E-Series Gen 2  ·  Astrodon Blue Tru-Balance E-Series Gen 2  ·  Astrodon Red Tru-Balance E-Series Gen 2

Accessory: QHYCCD PoleMaster  ·  ZWO 8x 1.25" Filter Wheel (EFW)  ·  Hotech 2" SCA Self-Centering Field Flattener  ·  MoonLite CFL 2.5" Large Format Focuser


Dates:May 26, 2019July 1, 2019July 2, 2019July 4, 2019

Frames:
Astrodon Blue Tru-Balance E-Series Gen 2: 213x60" (3h 33') (gain: 0.00) -20C bin 1x1
Astrodon Green Tru-Balance E-Series Gen 2: 172x60" (2h 52') (gain: 0.00) -20C bin 1x1
Astrodon Lum Tru-Balance E-Series Gen 2: 730x60" (12h 10') (gain: 0.00) -20C bin 1x1
Astrodon Red Tru-Balance E-Series Gen 2: 111x60" (1h 51') (gain: 0.00) -20C bin 1x1

Integration: 20h 26'

Darks: ~50

Flats: ~50

Bias: ~250

Avg. Moon age: 20.30 days

Avg. Moon phase: 14.56%

Bortle Dark-Sky Scale: 6.00


Basic astrometry details

Astrometry.net job: 2789230

RA center: 15h 38' 27"

DEC center: +59° 24' 3"

Pixel scale: 0.649 arcsec/pixel

Orientation: 135.304 degrees

Field radius: 0.338 degrees


Resolution: 3000x2260

Locations: Backyard White Zone Observatory, Taylor, MI, Michigan, United States

Data source: Backyard

Description

I believe this is the last capture of my galaxy season. It has been a rough season here in my red zone with a bortal sky scale of 6.0. Looking forward to narrowband again with the milky way rising.

Not as well-known as the Leo triplet NGC 5981, 5982 and 5985, collectively known as the Draco triplet are a fine group of galaxies high in Draco.

Unlike the Leo triplet however these galaxies are probably not related and reside at different distances so the triplet is purely a line of sight effect. NGC 5985 is about 120 million light years away, NGC 5982 about 130 million years and the small edge on NGC 5981 about 100 million light years away. However given the errors in astronomical distance measurement they could still be related.

NGC 5981 is quite a small dwarf galaxy. NGC 5982 and 5985 were found by William Herschel in 1788 but NGC 5981 had to wait until 1850 when it was found by J Stoney at Birr castle, probably with the 72".

NGC 5985 is an almost face on spiral and probably the easiest of the group so see. It is classified as a Seyfert type 1 galaxy with an active black hole at its nucleus. It is also classified as a LINER.

NGC 5982 is classified as an elliptical galaxy class E3. Although it looks quiescent now deep images reveal shells surrounding which are the results of a merger with another galaxy. These shells were found in the optical but were among the first to be discovered in the mid infra-red using data from Spitzer. NGC5982 may also be an active galaxy hiding a black hole. The merger probably happened about a billion years ago. Although it is an elliptical galaxy it also contains a young population of stars, perhaps as a result of the merger. Both 5985 and 5982 are visible in telescope as small as 15cm from a dark site.

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Draco Triplet • NGC 5985, 5982 & 5981, 



    
        

            Douglas J Struble