by Jay Reynolds Freeman
Not wishing to lose a good night of serious deep-sky observing to chasing bright and familiar things, I decided to attempt a Messier marathon in an unusual way: On the Saturday nearest the present new Moon, I went hunting Messier objects in broad daylight. Many of my friends and fellow amateur astronomers were suspicious of my ability to accomplish anything thereby, but of course, none of them have nearly as much observing experience as I do, and besides, I have Refractor Red, my 55 mm Vixen fluorite. If it can find the Herschel-400 objects by night, surely the Messier list by day would not be too difficult.
One advantage of daylight deep-sky observing is that there is far less problem with light pollution: Most outdoor lighting is turned off in the daytime. Hence there is no need to travel far in search of a particularly dark site. Furthermore, you don't need a red flashlight, a simple piece of red cellophane held between your charts and the Sun will suffice. In addition, there is less chance of dew, though neighbors' lawn sprinklers are sometimes a local hazard.
Of course, star-hopping is more difficult, but I had previously determined the azimuths and elevations of various tree branches, telephone poles, chimneys, and the like, as seen from my front yard. So, with the aid of a simple planetarium program, I was able to identify the stars in the field of a high-power eyepiece when the telescope was aimed tangent to these local fixtures, and take it from there. No doubt users of computer-controlled telescopes will have a particular advantage for this kind of work; I am anxious to hear how well they fare.
As an aid to dark adaptation, I observed with a black knit ski cap pulled down over my face. I had cut holes through it over both eyes, and wore a jeweler's loupe, with optics removed, strapped over my observing eye, further to constrain the view. I plugged the loupe with a blackened cork when I was away from the telescope for extended periods of time, to save the strain of holding my eyelid shut. The police were most curious about this apparel when they came by; perhaps my program would not have been so frequently interrupted if my jeans and sweat shirt had not also been black, or if I had left my long black cape inside.
I have always sought to stress the importance of observing technique in deep-sky work, and it is all the more vital in day-lit work. Averted vision seemed less than normally useful, but jiggling the telescope helped a great deal, as did lots of heavy breathing. Remember also, that patience is a virtue. And I breakfasted and lunched on bilberry jam. Yum.
I expect that most of you are sufficiently familiar with my work to anticipate how much success I had at my marathon, so I will save discussion of the details of the observations for a subsequent posting. I will have plenty of time to prepare it, for after all, the opportunity to perform a Messier marathon when the Sun is up comes but once a year...