70 mm, zoom eyepiece, city lights, and Messier objects
By Jay Reynolds Freeman

On the evening of October 6, 1998, I took my recently purchased Vixen 70 mm f/8 fluorite refractor into my yard in Palo Alto, California, to see if I could chase down a few Messier objects in the short time before Moon rise. The telescope still had no finder, so I decided to us emy 8-24 mm Vixen zoom eyepiece. At the lowest magnification, the Vixen has an apparent field of view of 45 or 50 degrees, which gave an actual field of a bit over two degrees, which was wide enough for finding things by squinting along the tube.

The teapot of Sagittarius was pouring out its last dregs over the southwestern horizon. The background sky was so bright that I could just barely see the stars that define its outline, with my unassisted eyes. Nevertheless, I found the elongated cluster at the center of M8 in short order, using the Zoom eyepiece's widest field. Adjusting the magnification showed some of the nebulosity associated with the cluster, best seen for me in these conditions at about a 2 mm exit pupil. Sweeping north picked up M20 -- the brightest parts were just barely visible with averted vision, again at about a 2 mm exit pupil. Nearby M21 was showing resolution.

Things got a little easier as I lifted the line of sight up out of the murk. M23 was granular to resolved, M24 (the Sagittarius Star Cloud, not the "gathering spot") showed many stars and much granularity across its entire width, and bright M25 -- a large, pretty, and much neglected object -- provided a sparkle of glittering stars. Next I found M18, granular to resolved near the north edge of M24, and then scanned north of it for M17, the Swan or Omega Nebula.

Here the zoom eyepiece revealed its other virtue, of being able to find even narrow ranges of magnification that produce the best view. M17 was difficult, so low and with so much city light, but fiddling with the zoom control revealed a particular setting at which I could actually make out the familiar shape. It was fascinating to watch how the background sky darkens as I changed magnifications.

Next I moved northward, looking for M16, but the rising Moon and the descending object kept me from finding it. No matter, there were plenty of things handy that were less sensitive to light pollution. A little sweeping turned up M11, well resolved with its one prominent star, at the higher ranges of the zoom's magnification. I star-hopped to M26, but could not quite resolve it. Moving the field north of Aquila turned up the indistinct glow of M71, and a short star-hop revealed the distinct apple-core shape of M27.

I lined up on beta Cygni -- Albireo -- and took a moment to enjoy the blue and yellow color of this wide pair. I have heard it said that colorful doubles appear best at low magnification, but I found the color contrast somewhat more prominent at 70x than at 23x. Perhaps the brighter sky glow at the lower magnification was washing things out.

Anyhow, I star-hopped to M56, and then to M57. The former showed itself only as a faint glow, but the Ring Nebula revealed its characteristic shape at 70x, just as it was slipping behind the crown of one of the birches beside my house. Before the tree ate all of Lyra, I scanned north, picked up zeta Lyrae -- an easy split at 23x -- then on to epsilon. The double-double was tough with so little magnification, but I got a narrow yet clear split of both epsilon-1 and epsilon-2, at 70x.

A view of Jupiter rounded out the evening. I had just missed the end of a transit, it appeared, for one of the inner Galilean satellites -- I am pretty sure it was Io -- had just cleared the planet's disc.

It was a fine night, and another testimonial to how much fun it can be to play with pretty little telescopes in big ugly towns.