The forecast for Southern Utah calls for clear and cold skies all week long. I may get the refractor out on the driveway if the seeing is excellent. Was hoping to try to split Sirius so I was wondering what the ideal magnification would be to see the pup. May also try for "e" and "f" stars in the Trapezium as well. Has anybody split Sirius in the past couple of years? Clear Skies, Debbie
I haven't split Sirius in decades, but from what I remember, very high magnification was needed. What scope do you plan to use? If a Newt with a rotatable tube, you can use the spider diffraction spikes to your advantage by putting the pup between the spikes. They will draw glare away from Sirius itself and slightly improve contrast close to the main star's diffraction disk. You may need at least 10" of aperture to resolve it at current separation. Perfect skies help, as well as optics at thermal equalibrium. And get it as close to the meridian as possible (highest altitude). Good luck, let us know how you do! On Mon, Jan 14, 2013 at 9:22 PM, Debbie <astrodeb@beyondbb.com> wrote:
The forecast for Southern Utah calls for clear and cold skies all week long. I may get the refractor out on the driveway if the seeing is excellent. Was hoping to try to split Sirius so I was wondering what the ideal magnification would be to see the pup. May also try for "e" and "f" stars in the Trapezium as well. Has anybody split Sirius in the past couple of years?
Chuck, I may try it with the 15" dobsonian reflector at the St George Star Party if the conditions permit. I have decided not to take my refractors on any dirt roads from now on. I heard if you get the 2 stars between the diffraction spikes you can see the pup clearly at high magnification. The weather is finally starting to warm up some so I will see what the conditions are Friday. If I can get some decent seeing then I will pull out the William Optics 120mm f/7.5 refractor and finish some of the doubles I have been viewing. Seeing hasn't been very good these last couple of nights. My last clear and cold night was on Jan 4th. I had good seeing but blew a fuse and lost power. The other two fuses were bad as well so I had a short and sweet observing session. Spent some time observing Orion doubles and open star clusters in Auriga and Gemini. Went to Radio Shack and bought some more fuses so this won't happen again. I may put on the ski pants to stay warm. Since I don't ski I will use them for observing and fishing in the winter. Clear Skies, Debbie On Wed, Jan 16, 2013 at 8:26 AM, Chuck Hards <chuck.hards@gmail.com> wrote:
I haven't split Sirius in decades, but from what I remember, very high magnification was needed. What scope do you plan to use? If a Newt with a rotatable tube, you can use the spider diffraction spikes to your advantage by putting the pup between the spikes. They will draw glare away from Sirius itself and slightly improve contrast close to the main star's diffraction disk. You may need at least 10" of aperture to resolve it at current separation. Perfect skies help, as well as optics at thermal equalibrium. And get it as close to the meridian as possible (highest altitude).
Good luck, let us know how you do!
On Mon, Jan 14, 2013 at 9:22 PM, Debbie <astrodeb@beyondbb.com> wrote:
The forecast for Southern Utah calls for clear and cold skies all week long. I may get the refractor out on the driveway if the seeing is excellent. Was hoping to try to split Sirius so I was wondering what the ideal magnification would be to see the pup. May also try for "e" and "f" stars in the Trapezium as well. Has anybody split Sirius in the past couple of years?
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Here is a good discussion on the Pup from Cloudy Nights. http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Number/5624259/pag... On Wed, Jan 16, 2013 at 8:26 AM, Chuck Hards <chuck.hards@gmail.com> wrote:
I haven't split Sirius in decades, but from what I remember, very high magnification was needed. What scope do you plan to use? If a Newt with a rotatable tube, you can use the spider diffraction spikes to your advantage by putting the pup between the spikes. They will draw glare away from Sirius itself and slightly improve contrast close to the main star's diffraction disk. You may need at least 10" of aperture to resolve it at current separation. Perfect skies help, as well as optics at thermal equalibrium. And get it as close to the meridian as possible (highest altitude).
Good luck, let us know how you do!
On Mon, Jan 14, 2013 at 9:22 PM, Debbie <astrodeb@beyondbb.com> wrote:
The forecast for Southern Utah calls for clear and cold skies all week long. I may get the refractor out on the driveway if the seeing is excellent. Was hoping to try to split Sirius so I was wondering what the ideal magnification would be to see the pup. May also try for "e" and "f" stars in the Trapezium as well. Has anybody split Sirius in the past couple of years?
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Chuck Hards -
Debbie