February 2009

Tony Martinez

Each month I will describe sights of interest in the night skies of South Carolina. These sights will be broken down into three sections; what you can see with the naked eye, with binoculars, and with a small telescope. The best time to view the night sky is at and around the times when the Moon is not visible, what is known as a New Moon; which will occur this month on February 25th. For February, your best viewing nights will be from February 13th through February 28th. The Star chart below is set for Florence, SC on February 15th at 9 pm.


ScienceSouth’s New Astronomy Program!

On September 14th this year John Dobson will be 94 years old. In his earlier life, he spent 23 years as a monk. During his time at a California monastery, his spiritual questions about the universe lead to his physical probing of the universe with telescopes. Living a monk’s life of poverty, Dobson was forced to improvise. A reflecting telescope is the only scope that an amateur can easily build from scratch. In the early 1960’s, Dobson ground, silvered, and polished his mirrors, and then placed them in cardboard tubes. This left the final task of building a good inexpensive mount for his reflecting telescopes. Unlike traditional telescope mounts utilizing a tripod, and a sophisticated means of aiming the scope on the tripod, Dobson designed a mount that held the telescope in a stable rotating plywood base placed flat on the ground with a “lazy Susan” turntable. This inexpensive telescope and mount developed by a poor monk has now become the telescope of choice for amateur astronomers around the world. These Dobsonian telescopes, usually called “Dobs,” offer amateur astronomers the greatest viewing experience for the least amount of money.

In 1967 Dobson left the monastery, and began his second contribution to the world of astronomy. Dobson wanted the world to see the beauty of the universe. However, asking people to come somewhere to look through someone’s telescope would attract only a small portion of the general population. Dobson took another approach. His homemade Dobs had a great deal of light gathering ability; therefore, many nighttime objects would be visible even in the poor light conditions found in cities. So Dobson took his telescopes to the street. He would set up a telescope on a sidewalk at different locations in San Francisco, and let passersby’s view various sky objects. Dobson then founded a group called the San Francisco Sidewalk Astronomers. As of today, there are many sidewalk astronomy organizations throughout the United States.

To celebrate the International Year of Astronomy, ScienceSouth has initiated our own Sidewalk Astronomy Program. Each month we will bring our telescopes out on the sidewalks of the Florence area. For nighttime viewing we will use a 10” Dob (of course), and for daytime viewing we will use a solar sunspotter, which projects a large image of the Sun, which will allow us to see any sunspots present. In addition, we will also use a special solar telescope known as an H1α solar telescope. This scope will allow you to see the solar prominences as they erupt off the surface of the Sun. A typical view is shown in the image below.

Many solar prominences are short lived, so on any given viewing day you may see one, none, or several appear on the edge of the Sun. By filtering out all the light except one emission wavelength from the hydrogen atom, this special telescope allows you to visualize these hydrogen rich eruptions of the Sun. These prominences are often several thousand miles long. In the image below, the “blue ball” shows the size of the Earth compared to a typical prominence.

So throughout the year, look for the ScienceSouth sidewalk astronomers. We may show up at malls, the library, sporting events, etc. I will keep you updated on our Sidewalk Astronomy program in my future columns.

Comets: This month’s special event is the arrival of Comet Lulin. Lulin is a unique comet in that its orbit differs from usual comet trajectories. It is traveling almost on the plane of the planets, plus it is traveling opposite the direction the planets travel. This means that it will have the fastest apparent speed of any known comet. Its closest approach will be on February 24th, although you can see it before and after that date. Whether or not it will be visible to the naked eye cannot be predicted with certainty, however, as of now it is believed that it will be an easy binocular object. Due to its trajectory, Comet Lulin may be the only comet that you will ever be able to see move in real time through your binoculars. Almost every comet takes several hours to see even a minor change in position. If we can see its motion in seconds or minutes, it will be a real astronomy thrill! Use the constellation Leo as your guide as shown in the image below. Most binoculars have a threaded hole on the bottom for mounting on a tripod. If possible, use a tripod to attempt to see the motion of Lulin.

Naked Eye Sights: Watch in the west as Venus makes its turn and begins to move lower in they sky beginning at the end of the month. Look to the east and watch as Saturn makes its return as a night sky object. Saturn will first become obvious at mid month, reaching about 35 degrees above the horizon by month’s end.

If we get lucky, Comet Lulin may become visible to the naked eye.

Binocular Sights (7 to 10 power): Comet Lulin is the target of choice this month.

Telescope Sights (60-100mm): Check out Comet Lulin. Also, visit Saturn on its return to the night skies, and note the scarcity of its ring as it tips toward us this year.

See you next month.