Friday, February 22, 2008

Saturn at 480x

The evening was clear and cold and I needed to take a trip to Seabrook for some cold medicine, so I set up the XT8i and started the cooling fan before leaving. About an hour later I returned and looked at Saturn in the 13mm Hyperion. Crisp and clear image, and I thought I could see the Cassini Division! So I went to the 5mm and the planet just popped out, totally in focus with the CD clearly visible in direct vision, for the first time for me. Bands on the planetary cloud cover were clearly visible as well.

With the 5mm EP the mag is already at 240x but I figured why not try the 2x barlow as well, so we went to 480x and amazingly the image held together well. CD still plainly visible, but of course the image only stays in the FOV for about 10 seconds.

The movements of the scope at this magnification are so tiny that I can see a real need to improve the stiction/friction properties of the dob base. Luckily there are many web sites describing upgrades to these areas (different types of surface, Pledge furniture polish, beeswax, replacing some of the UHMW plastic with teflon or Ebony Star, etc.) One of these days... and I'm definitely planning on flocking and baffling the interior of the tube to improve contrast, since there is so much artificial light in most places I'm observing from.

Tuesday, February 19, 2008

Tuesday, February 19, 2008

The weather has been typical New England winter weather, but this morning was forecast to be clear so at 5am I headed across the street to Hampton Beach State Park for an hour or so of observing with the XT8i.

The sun was coming up quickly, so it was a race to find and identify two stars for the Orion COL alignment. Polaris was going to be star #2, but I used the good old planisphere to find Spica as star #1. Quickly swing to both stars, don't bother with high powered eyepiece - bingo, warp factor -0.5. Good enough!

Now what to look at in the remaining minutes? I decide to take the tour, but I have to select the April tour since the February tour assumes you are out at a 'normal' time like 9pm. M3 is the first target - wow, I have never seen it before and it's just beautiful even as the sky lightens around it. A globular cluster, clearly visible with the 13mm Hyperion at about 92x.

I tried a few more objects, but none were visible, so I used the scope and COL to identify some stars and begin to learn my way around the constellations. A bright star in Scorpio turned out to be Antares, and above Spica in the west was Arcturus (easy to identify if you can find Ursa Major, the big dipper, using the 'arc to Arcturus' mnemonic.

Now it was really getting light, so time to take a peek at Jupiter, saved for last since it really shines brightly even against a lightening sky. Jupiter is still very low, maybe 15 degrees above the horizon, so there was very little detail visible. I could see a few bands, but mostly the planet's detail was obscured by clearly visible high winds in the atmosphere. However, the Galilean moons were clearly visible, three on one side and on on the other.

After this, I packed up and drove back home, then took Samantha to the beach again for our morning walk.