Quote:
Originally Posted by AG Hybrid
Well spotted it again tonight. Had to wait for "sucker holes" in the clouds so I can get some clear sky for Sirius.
Here was my log of events:
*Removed cover off my 12" dob.
*Rolled it out of a rather warm garage.
*Extended the OTA to full length.
*Checked collimation and made adjustments accordingly.
*Selected a 14 min Delos. This gives about 106x magnification and an exit pupil of about 3.3 mm
*Turned on the rear fan which both cools the mirror and due to selective baffling pushes air over the primary effectively eliminating the boundary layer.
*Pointed the scope at a random star that was near where the OTA was pointing and brought it to focus.
*Waited about 2-3 min for a hole in the clouds to open up around Sirius.
*Moved Sirius to the center of the field of view in the eyepiece.
*Spotted Sirius B immediately at about 11 o'clock just above a diffraction spike located at 10 o'clock from Sirius.
This was all done in the space of about 10 minutes. Sometimes folks you just need light gathering power and resolving power. With the clouds moving fast overhead obviously seeing was pretty average too.
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Hello Adrian .
Yes- it now appears to be established that aperture is a big advantage in all the reports coming in; though it also appears that a nice refractor in the 100mm range will do it also, but with difficulty: VIZ Allan ; but not yet for Morton in his superb Tak.
The cooling fans also would have been a must with such a large mirror - 12" about the maximum limit of what some seasoned doubles observers say is required, so as not to be so affected by average seeing conditions, which is less of an issue with smaller much apertures.
You make it sound so easy , but it's NOT and you are a seasoned observer with vast experience, and 10 O'clock is where it should be East -following; so well done once in a remarkable time frame, and through sucker holes!!!
Cheers bigjoe.