THE SOUTHWORTH PLANETARIUM
207-780-4249 www.usm.maine.edu/planet
70 Falmouth Street Portland, Maine 04103
43.6667° N, 70.2667° W
Founded January 1970
"Nothing attacks a flu like 18 holes of golf."
THE DAILY ASTRONOMER
Monday, April 18, 2016
Pandora Minor
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LASER SHOWS!
ASTRONOMY SHOWS!
The Southworth Planetarium rocks hard this April vacation week.
Astronomy shows at 11:00 a.m and 1:00 p.m.
Lasers shows at 12:00 p.m, 2:00 p.m., 3;00 p.m, 7:00 and 8:00 p.m.
all week long!
Consult our web-site www.usm.maine.edu/planet for more information.
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Since we vanished last week due to alleged illness, we will not be off this week as we experience all of Laser Mania's two dozen tentacles. Instead, we'll attempt to clear out much of the parchment still stuffed in Pandora's Jar. For those who've just arrived, Pandora's Jar is the dome bin where we store questions that audience members, DA subscribers, and other sufferers ask us. We write these questions on parchment paper and let them ferment in Pandora's Jar. This week, we are determined to address as many of these questions as possible. On Friday, of course, we'll still have our weekly quiz!
Today, we offer quick answers to some of the more straightforward questions we found in Pandora's hidden depths. Find answers to other questions on our "Ask the Staff Astronomer" web-site: http://usm.maine.edu/planet/ask-staff-astronomer
"I know that Alpha Centauri is the closest star system to the Sun, but we can't see it here in Southern Maine. How far south do you have to travel to see it? How bright would it appear?" -K. Heldenbrand. Freeport
Although some people claim that an observer would have to travel to the Southern Hemisphere to see Alpha Centauri, one can see it at any point south of 30 degrees North latitude. So, it is visible in the southern regions of the United States. Of course, it is easier to see in the Southern Hemisphere. At the latitude 60 degrees South, Alpha Centauri would pass directly overhead.
Alpha Centauri next to Beta Centauri and the Southern Cross.
(Image: Akira Fujii)
Although Alpha Centauri is the closest star system to the Sun, it is not the brightest star in the sky. It is the third brightest star in the night sky. Sirius, the brightest star, is about 2.5 times brighter. However, Alpha Centauri is slightly brighter than Arcturus, the alpha star in Bootes.
"Is it true that the Sun is powered by the same process as the atomic bombs used in World War II?" -Y.T, Portland
Not exactly. The atomic bombs used against the Japanese during World War II exploited the power of nuclear fission, the "splitting of atoms," which released the potent binding energies within atoms. The materials within the two atom bombs used on Japan were Uranium -235 and Plutonium-239. The Sun generates energy by thermonuclear "fusion," in which lighter elements are fused together to form heavier elements. In the case of the Sun and most stars, the lighter element is hydrogen and the fused element is helium.
We should point out that nuclear fusion bombs, called H-bombs (or Hydrogen bombs) were developed in the early 1950's. Most nuclear bombs in stockpiles today are fusion bombs, which are more efficient and lethal. Fortunately, no H bomb has ever been used against people.
"Will the Sun become a black hole someday?"
-V,M, Indiana
No. The Sun is not nearly massive enough to become a black hole. Instead, it will eventually cast off its outer layers as a planetary nebula and then leave a white dwarf core behind. Only the highly massive stars, with masses at least 8-10 times greater than the Sun, will ever become black holes.
Our part of the galaxy contains many planetary nebulae, so named as they resemble planets when viewed telescopically. A famous example is the "Ring Nebula," in Lyra the Harp. Although no two planetary nebulae look alike, the Ring Nebula looks similar to how the Sun will appear when its life cycle ends.
The Ring Nebula in Lyra the Harp. A planetary nebula about 2,283 light years away. The Sun will become a planetary nebula in about 6.5 billion years. While it won't look exactly like the Ring Nebula, the Sun will be similar in appearance after its life cycle ends. (Image credit: NASA)