M101 was among the first "spiral nebulae" identified as such. In
smaller telescopes is visible only the central region of this galaxy. On images,
M101 is revealed as one of the most prominent Grand Design spirals in the sky.
The distance of M101 has been determined by the measurement of Cepheid variables
with the Hubble Space Telescope in 1994/95 to be about 24 +/- 2 million light
years and it has a linear diameter of over 170,000 light years .
M101 obtained through a
refractor William Optics FLT 98/618; TeleVue 0,8 reducer/flattener; SBIG ST-8300C CCD; 15x6 minutes. Mount
Celestron AVX, guider ZWO ASI120C
Image
is taken with Celestron Pixcel 237 CCD Camera through a C8 at f:3,3. LRGB image
is assembled of luminance image (25x30 second) and RGB image ( Red 11x30 second,
Green 10x30 second and Blue 15x30 second). Processed in CCDSoft v5, AIP for
Win and Photoshop.
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