| Globular Cluster M3 - DSLR |
The globular cluster M3 lies in the constellation Canes Venatici, on the border with Bootes. Although it may contain as many stars at the Great Hercules Cluster M13, it
is a third farther away at a distance of about 33,000 light years, and therefore somewhat dimmer and visually smaller. Furthermore, the cluster contains a dense core, with
half of its 500,000 stars contained within an 11 light-year radius of its core. For comparison, only a dozen stars reside within 11 light-years of our sun. M3 is also notable
for the unusually high number of variable stars, which have been used to calculate the distance to the cluster. Visually through a telescope, the dense central concentration
stars of M3 obscures resolution of the core. M3, truly, hides its heart from us.
The image above is a cropped "snapshot" with a Canon 60Da, averaging just four 1-minute exposures at ISO 1600, through an Astro-Physics Ricardi-Honders 12" f3.8
telescope. To keep the test simple, the image was obtained without guiding, used the camera's internal dark subtraction, and no flat field. I did not do any fancy
processing, just curves and levels in Photoshop Raw mode, before stacking the 4 images.
.
A comparison CCD image through a telescope with a similar aperture is shown below, obtained with an ST10XME camera, with an AP 0.67x reducer, through a 12"
Meade LX200R telescope. I combined exposures of 25 minutes of red, and 20 minutes each of blue and green. Extensive processing was applied with Maxim DL,
CCDstack, and Photoshop.
is a third farther away at a distance of about 33,000 light years, and therefore somewhat dimmer and visually smaller. Furthermore, the cluster contains a dense core, with
half of its 500,000 stars contained within an 11 light-year radius of its core. For comparison, only a dozen stars reside within 11 light-years of our sun. M3 is also notable
for the unusually high number of variable stars, which have been used to calculate the distance to the cluster. Visually through a telescope, the dense central concentration
stars of M3 obscures resolution of the core. M3, truly, hides its heart from us.
The image above is a cropped "snapshot" with a Canon 60Da, averaging just four 1-minute exposures at ISO 1600, through an Astro-Physics Ricardi-Honders 12" f3.8
telescope. To keep the test simple, the image was obtained without guiding, used the camera's internal dark subtraction, and no flat field. I did not do any fancy
processing, just curves and levels in Photoshop Raw mode, before stacking the 4 images.
.
A comparison CCD image through a telescope with a similar aperture is shown below, obtained with an ST10XME camera, with an AP 0.67x reducer, through a 12"
Meade LX200R telescope. I combined exposures of 25 minutes of red, and 20 minutes each of blue and green. Extensive processing was applied with Maxim DL,
CCDstack, and Photoshop.
Music: You've got to hide your love away, by the Beatles
