Wednesday, May 11, 2016

first time using the 30-inch challenger telescope

Monday night I used the Challenger telescope on my own for the first time.  I knew it wouldn’t be a great night transparency wise, but I really wasn’t expecting to accomplish much serious observing.  I just needed time to learn the ropes.  The maritime metaphor is apt: a thick marine layer spread over all the surrounding valleys and looked like a ghostly ocean, its slow swells tinted by the setting sun.  As I stood high atop the wooden rolling steps holding the massive yet smoothly moving telescope in my hand, the wind blowing and the wood observatory creaking, I felt like a sailor atop the rigging of a ship setting off on a voyage.

I made the usual rookie mistakes.  I’d forget to change the secondary’s position after shifting the telescope to different parts of the sky, so I’d have to lower it back down and reset.  Or I’d forget to remove the 3” to 2” reducer from one focuser to the next.  Or I’d remember to change the secondary’s position but left my eyepiece in the wrong focuser.  I struggled to find a good position for the wooden rolling steps, and I rammed the concrete pier more than a few times.  I slowly learned which focuser position would be best for different angles of the scope.  It was weird looking at an object with my back to it and me on the steps looking up.  What is worse, I couldn’t get the key to open the cabinet to retrieve the finder scope eyepiece, so I was left to use just the Telrads to find targets.  The number of objects I can find with the Telrad is limited, but it was enough to get me through the night.  To use the Challenger effectively in the future I will need to learn how to use its digital setting circles.

I started out with the Leo Triplet, just to get orientated; both of M65 & M66 were bright and large, and NGC 3628 showed up well despite the sky not being fully dark. 

Once darkness came I wandered about the sky, practicing how to move the telescope.  Omega Centauri was pale, but it was submerged in low haze.   M68 was bright and broken apart, well resolved to the core.  There was a very faint round haze with a brighter core, just to the side of a nearby star: it was galaxy ESO-506-29.  M4 looked like a dot-to-dot picture of a barred spiral galaxy, with many curving loops and bands twirling away from the core, which has a bright red star just off center. 

Around midnight coyotes started singing to each other from two distant hilltops, and I noticed that the telescope had become pretty well drenched with dew.  I rolled the roof back over it and went into the observatory's classroom for a rest.  I fell asleep in a chair, and surprised myself awake at 2:30am.


By then the scope was dry, and the sky was still and much improved, registering a respectable 21.36 on the SQML.  Summer targets were higher.  There was Daneb, last seen sinking to the west on New Year’s night.  And what is Cassiopeia doing, rising already in the east?

NGC 6528 & 6522, twin globular clusters off Gamma Sagittari, the tip of the teapot’s spout, seen at 118x in the same FOV.   I experimented with different eyepiece combinations and filters while scanning around the summer Milky Way.  What does the core of M22 look like at 1463x?  Like shining from shook foil.

The core of M13 at 915x is a spangle of stars surrounding a small, grayish round cocoon of yet unresolved stars, with many dark paths twisting away from it.  All those dark lanes really surprised me.

M57 was pretty high so I gave it a try.  It was a fat greenish tube, with annular wisps pinched out from the NE and SW rims.  Its companion star was a bright steady button.  I increased magnification to 915x and, while bringing my eye to the center of the eyepiece, glimpsed the shy central star, which quickly withdrew into the dim central nebulosity.  I coaxed it back out with my averted eye.  It appeared for a while as a nebulous condensation, then the small round button of star flashed out, held with averted vision for about five seconds.  Tendrils of nebulosity reached from the inner ring into the dimmer center.  The Challenger’s spot-on tracking really helped because I could concentrate on looking rather than bumping the scope along to keep pace with the sky.  What is more, I was able to see IC 1296 as an extremely faint, small elongated glow off to the west of the Ring while viewing at 281x. 

In the morning I gazed over the marine layer as the sun tinted it, now from the brown brink eastward.  I hiked to the summit to take in the full panorama, and to add my small shadow to the shadow the Peak cast on the ocean of clouds below.

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