Hemisphere:  Northern  ·  Constellation: Hercules (Her)  ·  Contains:  Hercules Globular Cluster  ·  M 13  ·  NGC 6205

Image of the day 06/18/2020

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    Messier 13 - Great Globular Cluster in Hercules, 



    
        

            Luca Marinelli
    Messier 13 - Great Globular Cluster in Hercules
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    Messier 13 - Great Globular Cluster in Hercules

    Image of the day 06/18/2020

    Getting plate-solving status, please wait...
      Messier 13 - Great Globular Cluster in Hercules, 



    
        

            Luca Marinelli
      Messier 13 - Great Globular Cluster in Hercules
      Powered byPixInsight

      Messier 13 - Great Globular Cluster in Hercules

      Imaging telescopes or lenses: Teleskop Service ONTC 10" f4 Newton

      Imaging cameras: ZWO ASI1600MM Pro

      Mounts: Astro-Physics 1100GTO

      Guiding telescopes or lenses: Teleskop Service ONTC 10" f4 Newton

      Guiding cameras: Starlight Xpress Ultrastar Mono

      Software: Astro-Physics Command Center (APCC) Pro Software  ·  Photoshop CC  ·  PIXINSIGHT 1.8  ·  PHD2 Guiding PHD2 v2.6.5

      Filters: Astrodon Tru-Balance Gen2 E-Series - R 36mm  ·  Astrodon Tru-Balance Gen2 E-Series - B 36mm  ·  Astrodon Tru-Balance Gen2 E-Series - G 36mm  ·  Astrodon Tru-Balance Gen2 E-Series - L 36mm

      Accessory: QHYCCD OAG-M  ·  Tele Vue Paracorr Type 2  ·  Pegasus Astro Ultimate Power Box  ·  QHYCCD QHYCFW3-M


      Dates:May 3, 2020May 14, 2020May 19, 2020May 25, 2020June 4, 2020

      Frames:
      Astrodon Tru-Balance Gen2 E-Series - B 36mm: 74x120" (2h 28') (gain: 50.00) -20C bin 1x1
      Astrodon Tru-Balance Gen2 E-Series - G 36mm: 65x120" (2h 10') (gain: 50.00) -20C bin 1x1
      Astrodon Tru-Balance Gen2 E-Series - L 36mm: 511x60" (8h 31') (gain: 50.00) -20C bin 1x1
      Astrodon Tru-Balance Gen2 E-Series - R 36mm: 55x120" (1h 50') (gain: 50.00) -20C bin 1x1

      Integration: 14h 59'

      Darks: 50

      Flats: 20

      Flat darks: 50

      Bias: 100

      Avg. Moon age: 14.96 days

      Avg. Moon phase: 48.87%

      Bortle Dark-Sky Scale: 5.00


      RA center: 16h41m42s

      DEC center: +36°2642

      Pixel scale: 0.685 arcsec/pixel

      Orientation: 179.118 degrees

      Field radius: 0.510 degrees


      Resolution: 4304x3200

      Locations: Home Observatory, Schenectady, New York, United States

      Data source: Backyard

      Description

      Messier 13 or M13 is the brightest and largest globular cluster visible from the Northern Hemisphere. It was discovered by Edmond Halley in 1714 and cataloged by Charles Messier in 1764. With an apparent magnitude of 5.8, M13 is barely visible to the naked eye from dark skies on clear nights. It appears as a fuzzy spot in low power binoculars and shines like a jewel box in the eyepiece on a larger telescope. It iss a favorite Spring and Summer DSO of mine to observe with the 10in Newtonian telescope.

      M13 is about 145 light-years in diameter and is located at a distance of roughly 25,000 light years from Earth. It contains several hundred thousand stars, which implies an average distance between stars in the Cluster of roughly 1 light-year. However, in the core, stars are much more tightly packed with distances that can be as short as the diameter of the Solar System. Collisions among stars can happen and new stars are formed in the process. These young stars are called "blue stragglers" and form a standalone branch off main sequence in a Hertzsprung-Russell diagram of the stars in the cluster. The stars in the red giant branch of the cluster HR diagram are the oldest and can be used to date the beginning of the cluster formation, almost 12 billion years ago for M13. See also Tolga Gumusayak's APOD image with M13's HR diagram.

      While M13 is a bright DSO and does not require a lot of data, my intent was to resolve faint background galaxies and see how deep I could reach from my Bortle 5 suburban skies.

      The annotated images show fuzzies that can be separated from background unambiguously down to magnitude 22. There are a few galaxies around mag 22.5 that can be kind of resolved but it starts being questionable.

      I used the excellent tutorial by Andre Van der Hoeven to create a custom annotation in Pixinisght.

      References:

      - Wikipedia

      -B. Carroll, D. Ostlie, An Introduction to Modern Astrophysics, 2nd edition, Cambridge U. Press

      Comments

      Revisions

      • Final
        Messier 13 - Great Globular Cluster in Hercules, 



    
        

            Luca Marinelli
        Original
        Messier 13 - Great Globular Cluster in Hercules, 



    
        

            Luca Marinelli
        B
        Messier 13 - Great Globular Cluster in Hercules, 



    
        

            Luca Marinelli
        C
        Messier 13 - Great Globular Cluster in Hercules, 



    
        

            Luca Marinelli
        D

      B

      Description: Annotated image with galaxies from Hyperleda database. The apparent magnitude of the galaxy is reported.

      Uploaded: ...

      C

      Description: Inverted luminance image annotated with galaxies from Hyperleda database. The apparent magnitude of the galaxy is reported.

      Uploaded: ...

      D

      Description: Crop of the core region of the cluster with the Propeller highlighted.

      Uploaded: ...

      Sky plot

      Sky plot

      Histogram

      Messier 13 - Great Globular Cluster in Hercules, 



    
        

            Luca Marinelli