The long-awaited transit of planet Mercury across the face of our sun had finally arrived. As with many astronomical events, planning would be very important.
For me in Arizona that transit or solar crossing would be well underway by the time the sun rose. Therefore a clear eastern horizon would provide an advantage to witness the entire event, or at least as much as possible from Arizona. The transit was predicted to occur on the morning of Nov. 11, so a few days in advance I would seek out my eastern horizon, a task not so easily accomplished here in Arizona—our beautiful pine trees and majestic rock formations that are generally an inspiration to artists and photographers can be a problem for those studying the sky.
One advantage Floridians in a flat state enjoy is that eastern and western horizons are readily available.
For astronomy, I like to stay as close to home as I can be, for equipment can be delicate and expensive. And one never knows who or what one might meet in the dark. Another thing is that the support of your home will give access to tools you might need or things you may have forgotten.
After more information was gathered, I realized my own driveway would be acceptable for this event. I would just have to wait until the sun rose above some pine trees; that was okay because even though the transit would be about half over by the time I could see it, the most important segment, the egress, where Mercury would exit the solar disk, would be free of obstructions.
This particular event would occur at dawn during daylight, so things would be a bit different. The first thing one notices about solar astronomy is that it is daylight and manipulating cameras and telescopes can be done with ease! The next thing is that the overwhelming glare of our nearest star reminds us of the importance of properly filtering optical equipment when viewing or photographing the sun.
Something also to consider is the polar alignment of your telescope's mount. This must be done to ensure proper tracking of a celestial object, keeping it centered in the eyepiece.
There are several ways to do this, however, the most efficient way to align my mount is to view certain stars through the center of the right ascension axis. This is done by way of a small telescope bored through the center of that axis. That being said, the mount must be aligned in the darkness of night. Once aligned, many hours might pass before the desired object comes into view.
Another reason to stay close to home, where it is warm and comfortable waiting for the event to occur.
One thing I can say about my neighborhood in Sedona is that I can leave expensive equipment unattended, sometimes overnight, and no one would disturb it. Neighbors here voluntarily shut off yard lights when they see a telescope in my front yard, which is unnecessary for solar astronomy but still a very kind and thoughtful gesture.
Very sophisticated people here in Sedona.
At about 9 a.m. the sun cleared the trees and there it was, as predicted, Mercury in the center of the solar disk. I was using a Lunt hydrogen alpha telescope that would reveal the sun’s chromosphere, or outer space, and the planet as it crossed the sun and hopefully produce the most dramatic images.
Mercury was surprisingly small compared to the solar disk, so I gradually increased magnification by way of the eyepiece projection method until I was satisfied with the image. Eyepiece projection is where an eyepiece is placed between the telescope’s objective and the camera body.
For the next couple of hours, I made some still photographs and a video of the last 10 minutes of Mercury’s egress ... this I would time-lapse into about one minute.
I have said it before ... but being in the right place at the right time is paramount, and being well prepared is a must for fine astrophotography.
I had invited several neighbors to share this event with me. But no one showed. I think I must have scared them off with my talk about the potential dangers when observing the sun. Don’t get me wrong, the sun and solar events can be observed safely ... but it must be done correctly and with confidence that you are doing things right.
The next transit of planet Mercury occurs in 2032, so we have plenty of time to prepare!