M13 was discovered in 1714 by Edmund Halley. The large globular cluster in the constellation Hercules is visible to the naked eye. It is about 26,000 light years away. More than 1,000,000 stars are concentrated in a region of about 160 light years diameter. The cluster has 600,000 times the mass of our Sun.
Image orientation: North is on top.
Telescope: Newtonian 250mm @f/4.8 on Losmandy G11 mount
Camera: MI G2-8300FR @-25°C
Exposure: LRGB: 8x300s / 5x300s / 4x300s / 5x300s. No binnig.
Note: Guidung with G0-0300 on OAG