Greetings, stargazers.
The summer Milky Way is one of the many things you get to enjoy if you are lucky enough to live in the Four Corners. From most big cities you might never get the chance to see it. On more than one occasion, I have heard from stargazing newbies something like: “What is that hazy patch? I thought tonight was perfectly clear!”
This is a particularly good time for binocular astronomy because of all the easy targets along the Milky Way. Especially for those who like to just lie back and scan the sky with no particular goal in mind. For astronomic use, the general rule for binoculars is bigger is better.
So you don’t wear out your arms before your eyes get adjusted to the dark, mounting binoculars on a tripod will make your experience more enjoyable. Binoculars that are 7x50 or bigger (and many binoculars that are smaller) almost always have a ¼-20 threaded hole in the front along the axis that changes the eye spacing. That is the thread size used on most photographic tripods. Quite often, this hole will be covered with a decorative cap, or a button with a logo on it, so you might not even know you have this feature if you don’t look for it. Most will unscrew without tools.
Your only challenge to mounting binoculars on a tripod is to get something to provide a 90-degree angle to the top of the tripod. Many companies sell such adapters, but I have used a corner brace from the hardware store and assorted ¼-20 nuts and bolts very successfully.
You will quickly find that unless your binoculars are offset from your tripod, that it will be practically impossible to point them directly overhead. A rod or board suspended off the axis of the tripod will do the job, but that will need a counterweight to keep the tripod from toppling.
The ideal solution to mounting binoculars on a tripod is a parallelogram mount. These mounts hold the binoculars well away from the tripod center and have an adjustable counterweight to offset a variety of binocular sizes. The parallelogram structure allows the offset binoculars to move up and down without changing where they are pointed. That is a great help at star parties where everyone is a different height.
Mars is dominating the southern evening sky. The nearby red star in Scorpius is Antares, meaning Rival of Mars. With Mars being relatively close to Earth right now, it appears so much brighter than Antares that you might wonder how anyone could think Antares could be a rival.
Jupiter and Saturn are both well positioned for telescope viewing in the early evening. It is also fun to see if you can see all four Galilean moons of Jupiter with binoculars.
Some of my favorite telescope targets are rising with the summer Milky Way. M8, the Lagoon Nebula, is faintly visible with the naked eye. With binoculars, numerous stars are visible as part of the open cluster associated with it. The glowing hydrogen gas that makes M8 so interesting will show up red in photographs, but because of the limitations of our eye sensitivity, we will only see this as a pale blue-gray fuzzy patch.
M4 is a globular cluster easy to find with a small telescope because it is little more than a degree west of Antares. M22 is a brighter globular cluster about 2 degrees up and to the left of the topmost star in the teapot of Sagittarius. There are many other globular clusters visible with telescopes, but none are as bright as M22.
The Delta Aquarids meteor shower will be July 28-29, but that is just a warm-up for the Perseid shower coming up in August.
Charles Hakes teaches in the Physics and Engineering Department at Fort Lewis College and is director of the Fort Lewis Observatory. Email him at hakes_c@fortlewis.edu.
Useful links
Astronomy picture of the day: http://apod.nasa.gov/apod
An astronomer’s forecast for Durango: www.cleardarksky.com/c/DrngoCOkey.html?1
Old Fort Lewis Observatory: www.fortlewis.edu/observatory
Four Corners Stargazers:
http://groups.google.com/group/Four-Corners-Stargazers
https://sites.google.com/site/fourcornersskies
www.facebook.com/groups/1549029695393951
