The Vineyard is an ideal place for stargazing, and of course comet-gazing. The skies are dark, and unlike in urban and suburban areas on the mainland, light pollution is not a problem.
Comet Lulin is fast-moving. Last week, the comet resided in the zodiacal constellation Virgo. This week it resides in Leo and next week it moves into Cancer. That is a lot of space to cover.
Stargazing and comet watching is a pleasant family event. Last Friday I was joined by my brother Jack and my sister Debbie who were visiting the Vineyard for the weekend. We all dressed warmly and went out to get a good look at the comet. Comets are beautiful wanderers, though faint, and often hard to spot. When you spot one, there is good reason to cheer.
The hard part of backyard astronomy has nothing to do with equipment, what you wear or the friends who join you. The trouble is always the weather. Last Friday night the air was clear but it was also blustery with a bitter cold breeze from the northwest. Temperatures dropped into the teens. The cold breeze kept up for most of this week, except on Tuesday night.
But last Friday we were determined to see the comet. We took frequent breaks and came inside to huddle near the woodstove and sip hot tea.
Through a telescope, Comet Lulin looks like a lot of comets that have passed over the Vineyard since I began stargazing as a child. It looks like a dust ball.
The center is as brilliant as a bright star, and the rest is all luminous fuzz. The magnification of the telescope tends to disperse the image, making it less interesting to watch.
Therefore low power view is usually better. The lowest power on even the largest telescope renders the comet an impressive sight.
Even so, comet watching is more poetry than science.
The color — the blues, greens and yellows that are sometimes recorded in photographs are left to the astronomers with the biggest scopes.
Photographing a comet is difficult unless the comet is as bright as Hale-Bopp, which passed over head 12 years ago.
The best way to take a picture is to use a slow shutter speed.
The photograph of Comet Lulin that was taken for the Gazette Tuesday night was shot with a camera with a shutter that opened for 30 seconds, and the telephoto lens wide open. The camera was not on a tripod; had it been on a stationary tripod, all the stars and the comet would have appeared as lines crossing the field of view. This is because the earth turns. Even a picture of the moon will be blurred if the exposure is longer than a few seconds.
My camera was parked piggyback on an eight-inch reflector telescope with a clock drive.
The camera was pointed directly at the comet. The telescope acted as a guide. The telescope is attached to a drive that was pointed at the North Star at the start of the evening, guaranteeing that any pictures taken during the night would be rendered sharp. The clock runs continuously.
The clock drive is convenient even for normal nightly viewing. For instance, when the telescope is pointed at Venus, I can walk away for 10 minutes and come back and Venus is still in view in the eyepiece.
For photographic purposes, a remote control device that looks like a cable television remote control device is used to make the fine adjustments necessary to make sure that the stars and comet stay stationery in the camera while the picture is being taken.
Digital photography has made a world of difference. Pictures can be checked within minutes on a computer and adjustments made.
In the days of Comet Hale-Bopp, before digital photography, we only knew we had a good picture after spending hours in the darkroom. By the time we knew we had the picture, dawn had turned to daylight.
Whether seen or photographed, comets are the pearls in the jewelry box. But they also are here today, and then quickly gone.