90 MilliMeters » seeing http://www.90mm.us Backyard Astronomy with Small Telescopes Fri, 23 Jul 2010 02:42:31 +0000 en hourly 1 http://wordpress.org/?v=3.0.1 Scanning Through Cassiopeia http://www.90mm.us/2009/10/07/scanning-through-cassiopeia/ http://www.90mm.us/2009/10/07/scanning-through-cassiopeia/#comments Wed, 07 Oct 2009 22:41:14 +0000 Dan http://www.90mm.us/?p=144 I’m going to try and get out there a little early tonight with my binoculars for a little scanning through Cassiopeia. The moon will rise around 8:18 PM EDT but will remain low enough until around 9:00 PM to get a few good views in. I guess I’m getting a little anxious. Before the full moon this month it skies were cloudy, now that we’re a few days past full moon and headed toward third quarter the skies have been clear but unsteady so seeing has been very poor. Makes me a little crazy sometimes. I was hoping to get some planetary observing done with Jupiter being so well placed, but, as you know, when seening is poor, objects in the eyepiece just boil.

Speaking of scanning through Cassiopeia, did you know, If we were able to observe our Sun from Alpha Centauri, the Sun would appear in Cassiopeia as a yellow-white 0.5 magnitude star. The famous ”W”of Cassiopeia would become a zig-zag pattern with the Sun at the leftmost end. Cassiopeia is positioned directly in the Milky Way.

]]> http://www.90mm.us/2009/10/07/scanning-through-cassiopeia/feed/ 0 Jupiter and the Great Red Spot http://www.90mm.us/2009/09/29/jupiter-and-the-great-red-spot/ http://www.90mm.us/2009/09/29/jupiter-and-the-great-red-spot/#comments Wed, 30 Sep 2009 02:39:24 +0000 Dan http://www.90mm.us/?p=97 One of the interesting features about Jupiter is the Great Red Spot (GRS). The GRS is a vast storm, spinning like a cyclone. I learned that the GRS would transit on September 28, 2009 around 11:17 PM EDT (you can get that information here) so I setup my DS-90 and got ready to watch. I know that this happens often enough that it shouldn’t be a big deal but, I never took tje time to really look at the event. The moon on this night was waxing gibbous and shining brightly just left of Jupiter.

I focused on Jupiter at x40 and then dropped in my 11mm Plossl for x90. Much to my disappointment, the planet seemed to boil. This is an effect of the atmosphere known as “Seeing”. While the sky was transparent, the view was poor. You can learn more about Seeing and Transparency here.

As I continued to look, waiting for breaks in the turbulent atmosphere, I caught a few glimpses of the GRS which appeared as a light grayish oval at x90. At x117 the seeing was just a nightmare so I stayed at x90 for the night. 

I will try to watch this event again in the coming weeks.

Clear Skise,

-Dan

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