Sunday, July 23, 2017

Will and his 13.1" Telescope . . .

Hi Dennis: 

Here’s a glamour shot of the scope at Pinnacles National Park.  We actually moved to a less scenic location, but with better horizons, for observing.

It was a fun night.  Even though it’s a bit past prime time for spring galaxies, my first target once it was sufficiently dark (after some nice views of Jupiter and especially Saturn) was M51.  Interesting coincidence, the “pinnacles” that give Pinnacles its name come from a volcano that erupted 23 million years ago…just about the same time the light we’re seeing from M51 started its journey.  The arms were apparent, but the northwestern sky at Pinnacles is the worst direction to look in terms of distant light domes.

I spent the rest of the night revisiting favorites among the milky way from Scorpius and Sagittarius up through Cygnus.  Nebulae looked bigger and brighter, and clusters richer with stars, than I’d ever seen them.  I spent a fair bit of time just panning around with a nearly 1.5° field of view provided by a 31mm Baader Hyperion Aspheric, with more detailed views provided by 20 and 11mm eyepieces.  My highest power eyepiece is a 6.7mm yielding about 223x, which I used on the planets, tracking was very easy at that power and I’m sure it could have done well at considerably higher powers if conditions and targets warranted tracking down a Barlow.

Incidentally, I have somewhat figured out the meaning of the circled “-2” on the side of the Coulter mirror.  It definitely has to do with the actual (as opposed to nominal) focal length (, although it’s not clear to me what the units are…definitely not inches but might be % (

Take care,

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