M 13
About image
The Globular Cluster of Hercules (also known as M 13 from its position in the Messier Catalog, or as NGC 6205) is a globular cluster visible in the constellation of Hercules. It is the brightest globular cluster in the northern hemisphere and is visible even to the naked eye given its apparent magnitude of 5.8.
Its angular diameter is 23 ', while its real diameter is approximately 165 light years.
M13 contains several hundred thousand stars: around its core, stars are about 500 times more concentrated than around the solar system.
The age of M 13 has been estimated to be between 12 and 14 billion years. Its distance from Earth is 23,157 light years.
In 1974 a symbolic attempt was made to send a message to other worlds. To celebrate a substantial expansion of Arecibo's 305-meter radio telescope (now unfortunately no longer operational), a coded message of 1,679 bits was transmitted to M13.
[text adapted from Wikipedia]
Technical data
Optic Tecnosky Apo refractor LT 130-910 with Riccardi reducer 0.75x (focal lenght 692mm, f/5.3)
Mount Skywatcher EQ8
Camera Moravian G3-16200 CCD with external filter wheel 7 positions
Filters Baader 50mm unmounted RGB
Guiding system Artesky Ultraguide 70mm
Exposure details R 46x120" bin1 -15C
G 43x120" bin1 -15C
B 51x120" bin1 -15C
Total integration 4h40'
Acquisition Voyager, PHD2
Processing Pixinsight 1.8, Photoshop CS5, NoiseXTerminator, BlurXterminator, StarXTerminator
SQM-L 18.2
Location Rescaldina (Italy), home terrace
Date 3/4/5/30/31 March 2025
© Roberto Marinoni 2019 - All rights reserved