Astronomy Part3

Astronomy An introduction to Astronomy for the BSA Astronomy Badge

Part 3: Deep Space

In this night view of the USA from space, we can see virtually every city, town and major highway lit up by the lights we have put up. These lights have destroyed our view of the night sky that our ancestors counted on to tell the seasons for planting and other things. They are also damaging to not only nocturnal animals such as bats and rodents, but other animals like birds, frogs, sea turtles and possibly humans.

Here we can see the summer sky as it looks from an area that has little or no light pollution. The constellations of Sagittarius (look for the teapot) and Scorpius are easily seen as is the Milky Way as we look toward the center of our galaxy.

Here is what many of us now see when they look at the same sky. While Sagittarius and Scorpius are still seen, most of the rest of the night sky, including the Milky Way are now drowned out by the lights of civilization. Groups like the International Dark Sky Association (www.darksky.org) are trying to get municipalities to more wisely light their towns so that we can lessen the impact of lighting on our night skies.

Here are the constellations we can see in the southern summer sky including Aquila, the eagle; Ophiuchus, the 13th constellation in the Zodiac; and Libra.

Here are the constellations we can see overhead in the summer sky including Cygnus, the swan, Delphinus, the dolphin, and the hero Hercules. What can we see with telescopes in this area of the Sky?

M20, The Trifid Nebula in Sagittarius Photo by Richard Bennion A former SPL with Troop 47, Foster City, California.

M16, The Eagle Nebula also in Sagittarius. Not to be confused with the constellation Aquila, The Eagle. Photo by Richard Bennion

The beaks of the Eagle are often call “The Pillars of Creation” as stars are being born in this area. Nebulas are clouds of gas and dust. They can be areas where stars are forming, where stars are dying or both.

M13 Globular Cluster in Hercules. Photo by R. Jay GaBany

M27, The Dumbbell Nebula in Vulpecula. Photo by R. Jay GaBany

Globular clusters are peppered around the nucleus of our galaxy. Imagine if the earth was located in a cluster like this, what our night sky would look like. These are just some of the many objects that can be seen with telescopes High in the summer sky.

In the Autumn night sky we can see the constellations Pegasus, the winged horse; Cassiopeia, the queen; Pisces, the fish; Aries, the ram; Perseus and Andromeda. We can also see the open cluster near Perseus and Aries known as the Pleiades, or the seven sisters.

M45, The Pleiades or Seven Sisters open cluster Photo by Richard Bennion

M31, The Andromeda Galaxy Photo by Richard Bennion

Open clusters unlike globular clusters are located through out our galaxy. The Andromeda galaxy is similar to our own galaxy and in an area with dark skies, can be seen with your eyes without the use of telescopes or binoculars. It takes the light of the Andromeda galaxy over 2 million years to reach us. In other words we are seeing this galaxy as it looked 2 million years ago.

This is the winter night sky as it looks from an area away from the lights of a city. The constellations of Orion, the hunter and Canis Major, the big dog are easily seen as we look toward the outer rim of our Milky Way galaxy.

Here are the constellations we can see in the southern winter sky including Taurus, the bull; Gemini, the twins; Cancer, the crab; and Lepus, the rabbit. In Canis Major we can see Sirius, the brightest star in our night sky. Also the star at Orion’s right shoulder is Betelgeuse.

M1, The Crab Nebula in Taurus Photo by R. Jay GaBany

The Horsehead Nebula in Orion. Located just under the far left belt star. Photo by R. Jay GaBany

The Crab nebula was born from a supernova seen by the Chinese on July, 4, 1054 AD. The star at it’s center is now a pulsar, a rapidly rotating neutron star. This pulsar was first known as LGM-1 for “Little Green Men” because it’s radio signal, first discovered by Jocelyn Bell, was first thought to be a signal from an alien culture.

The Crab nebula pulsar was not the only signal thought to be of extraterrestrial origin. In August of 1977, The Ohio State University’s “Big Ear” radio telescope received a powerful signal that lasted 72 seconds and appeared to originated from somewhere in the constellation Sagittarius. Jerry R. Ehman, a professor, and volunteer at the observatory, wrote “WOW!” on the printout of the signal strengths that the telescope had received. The strengths start at 0 (a blank space) and goes up to 9. For signals stronger that 9, the alphabet was used, A,B,C, etc. As you can see the strength of this signal got as high as “U”, the strongest ever seen. The signal was never repeated and it source is still debated today.

Photo by Richard Bennion One of the most famous objects in the winter sky is M45, the Orion Nebula. Located in Orion’s sword, this nebula is where stars are being born

The constellations of the spring sky including Leo, the lion; Virgo, the virgin; Hydra, the water serpent; and Corvus, the crow. In this area of the sky, we can see plenty of one kind of deep sky object: galaxies!

M65, M66, and NGC 3628 in Leo Photo by Richard Bennion

M104, The Sombrero Galaxy in Virgo. Photo by R. Jay GaBany

These are just a few of the many galaxies that are visible in this area of the sky. These galaxies are approximately 35 million light years away from us. Remember, the Andromeda galaxy is just over 2 million light years away.

Looking north we can see the constellations Ursa Major and Ursa Minor, the big and little bears. Notice that the asterism “The Big Dipper” is part of Ursa Major and the “Little Dipper” is part of Ursa Minor. Can you find Polaris, the “North Star”?

M81 and M82 in Ursa Major Photo by Richard Bennion

M51, The Whirlpool Galaxy in Canes Venatici. Photo by R. Jay GaBany

These are some of my favorite galaxies found in the northern sky. Can you see more distant galaxies near M51? What does our galaxy, “The Milky Way” look like?

This is what we think the Milky Way looks like. Notice where our sun is located, far from the center of the galaxy. The Milky Way is one of the millions of galaxies in the universe.

This panoramic image taken by the Hubble Space Telescope in 2009 shows just some of the many galaxies that are in the universe. There are 7,500 galaxies in this image. The faint red specks are over 13 billion light years away from us.

How can we see these wonderful objects in the sky. Binoculars and telescopes such as the 120 millimeter (4.72 inch) refractor on the left or the 10.1 inch reflector on the right. Of course there’s always the Hubble Space Telescope.

Above you can see how a refractor scope bends light through a lens while a reflector scope reflects light on mirrors. Some telescopes, such as a catadioptric types, a Schmidt-Cassegrain for example, both refract and bend light.

So let us return to our little home, Earth, and end our odyssey. I hope you have enjoyed this presentation and hopefully learned a few things too.

Credits: I would like to thank R. Jay GaBany, San Jose, California, USA http://ccd.cosmotography.com and Richard Bennion, Belmont, California, USA www.ewellobservatory.com for giving me permission to use their wonderful deep sky images used in this presentation. Photos of sunset and refractor telescope, telescope graphic by Steve Smith, Waynesville, Ohio, USA. Photo of reflector telescope by Gordon Beatty, Waynesville, Ohio, USA. Graphics of the night sky, constellations, and intro page created with Starry Night software, Simulation Curriculum Corp. Volume Visualization of the Orion Nebula film courtesy of the American Museum of Natural History and the San Diego Supercomputer Center. WOW! signal photograph courtesy of The Ohio State University Radio Observatory and the North American AstroPhysical Observatory (NAAPO). Night view of USA and Hubble photos courtesy of NASA/JPL-Caltech. Milky Way Galaxy graphic courtesy of NASA/JPL-Caltech/R. Hurt (SSC-Caltech).