February 22, 2008

Can a Tripod See First Light?


Tonight was first light with the new walnut tripod (my project during all those cloudy nights we've had recently). It has a fixed leg height, but I plan to use it only in the backyard and perhaps other flat places. I have an alt-az mount on the way, and am preparing for it. But the tripod worked beautifully under the GP, and I was able to observe with the Orion 100mm.
Besides the old standards, what grabbed my attention most tonight were four moons of Saturn, Cr 140 in Canis Major, VY Canis Majoris, and Rigel split in two.
Saturn was too edge-on for me to see the Cassini division in the 100mm, though I did not try very hard at 120x. The moons were great, though. Assuming the rings are at 3 and 9, one moon was at 9:30, one at 11:40, one at 3:45, and one at 4:15. The moon at 3:45 was about twice as far from the planet as the others. It was a wonderful sight.
Cr 140 is a bright cluster and would be even better if it were further north. I recommend it in the middle of a wide field. I saw it at 20x through a 30mm, 80-degree eyepiece which yields a true field 4 degrees wide. Even then Cr 140 loomed large in the middle.
VY Canis Majoris is a bloated giant, and is perhaps the largest star of which scientists know the rough size. It vacillates between magnitudes 7.4 and 9.6, and tonight it looked around magnitude 8 to me. It lies about 1.5 degrees southeast of Tau CMa and NGC 2362.
Rigel is always a treat. In the achromat, it is blue-white and framed by a soft blue halo. It's companion is blue, probably because the companion is in the halo. What is thrilling is seeing those two dots appear when focus is reached at 120x.

February 7, 2008

The Queen and her Court, and The Marshmallow

Last night was the new moon, and the day before that a cold front blew the moist Houston air into the Gulf. Under cloudless, transparent skies, in the backyard with the XT8, I visited an old friend and found a new.
First, I found NGC 2362, the Queen and her Court, my personal favorite open cluster. Tau Canis Majoris is surrounded by dimmer stars that follow her through the sky as if they adore her. It's a stunner.
Later, I found M47 and M46 and for the first time ever spotted NGC 2438, the planetary nebula in M46. It was not visible at 40x, but at 150x (with a new Baader Hyperion 8mm) it jumped out. It was brighter still at 240x, a great contrast to the dimmer but dense star setting of M46. The planetary is a ghostly marshmallow sitting in a box of loose precious stones!