Hemisphere:  Northern  ·  Constellation: Gemini (Gem)
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The Medusa Nebula, SH2-274, Abell 21, 



    
        

            Steven Bellavia
The Medusa Nebula, SH2-274, Abell 21
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The Medusa Nebula, SH2-274, Abell 21

Getting plate-solving status, please wait...
The Medusa Nebula, SH2-274, Abell 21, 



    
        

            Steven Bellavia
The Medusa Nebula, SH2-274, Abell 21
Powered byPixInsight

The Medusa Nebula, SH2-274, Abell 21

Technical card

Imaging telescopes or lenses: TS-Optics PHOTOLINE 115 mm F7 triplet apo

Imaging cameras: ZWO ASI533MC Pro

Mounts: Sky-Watcher EQ-6R Pro SynScan

Guiding telescopes or lenses: The Bellavia Basic-II 50mm f/7.5 guidescope

Guiding cameras: ZWO ASI 290MC

Focal reducers: TS-Optics TSRed279 0,79 Reducer

Software: Pleiades Astrophoto PixInsight  ·  IDEIKI AstroPhotography Tool (APT)  ·  Stark Labs Nebulosity 4.2  ·  Annie's Astro Actions V7  ·  Noel Carboni's Astro Tools for PhotoShop Noel Carboni Actions  ·  SharpCap Pro 3.2

Filters: ZWO Duo-Band Filter

Accessory: Starizona slightly modified 2" Filter Slider


Dates:April 4, 2021April 5, 2021April 6, 2021

Frames:ZWO Duo-Band Filter: 75x240" (5h) (gain: 100.00) -5C bin 1x1

Integration: 5h

Darks: ~30

Flats: ~30

Flat darks: ~30

Avg. Moon age: 23.24 days

Avg. Moon phase: 38.62%

Bortle Dark-Sky Scale: 3.00

Mean SQM: 21.43

Mean FWHM: 3.73

Temperature: 1.50


Basic astrometry details

Astrometry.net job: 4394531

RA center: 7h 29' 2"

DEC center: +13° 14' 56"

Pixel scale: 1.192 arcsec/pixel

Orientation: 354.419 degrees

Field radius: 0.497 degrees


Resolution: 2400x1800

Data source: Traveller

Description

The Medusa Nebula, SH2-274, Abell 21, is a planetary nebula in the constellation of Gemini. It was originally discovered in 1955 by University of California, Los Angeles astronomer George O. Abell, who classified it as an old planetary nebula. Until the early 1970s, the nebula was thought to be a supernova remnant. With the computation of expansion velocities and the thermal character of the radio emission, Soviet astronomers in 1971 concluded that it was most likely a planetary nebula. As the nebula is so large, its surface brightness is very low, with surface magnitudes of between +15.99 and +25 reported

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The Medusa Nebula, SH2-274, Abell 21, 



    
        

            Steven Bellavia