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Gathering the Wrong Light July 21, 2012

Posted by pjhsscience in Astronomy, Observatory, telescopes.
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Imagine for a moment, driving at night through the vast and unpopulated expanses of the western deserts of North America. Frequently, some of the most amazing photos of our night sky are taken from locations such as these and for very good reason. The only light visible is that which is being projected from the stars above. Back to yourself in the car now, you are approaching a town, a rather large town. As you get closer the lights from above start to fade as your eyes are drawn toward the glowing city. It’s not that street lamps and stoplights are more of an amazing site than our celestial blanket; it’s just that those lights are quickly becoming the only thing visible. You are experiencing the plague of metropolitan exorbitance, a form of pollution, light pollution.

Light pollution is one of the newest forms of pollution plaguing modern society. Before electric grids the night sky, even in large cities, was still an intriguing sight. As technology evolved and electricity flowed we were able to combat our limited night vision by lighting the night. As the world at night become brighter we covered the sky by uncovering what lies beneath us at night.

Lighting too has evolved throughout time. We are becoming more familiar with the glow of HID, or high intensity discharge lights, while becoming less familiar with the arrangement of the heavens. To get a view of just how encroaching light pollution can be we need only look at the animal kingdom. Lighting areas where light is not naturally present at night is having a major effect on nocturnal animals. Sea turtle hatchlings are often confused by brightly lit beaches and wander away from safe havens. Migration patterns of many species of waterfowl have been altered due to excess lighting. Feeding is a naturally performed at night for nocturnal creatures and feeding patterns have brought unwanted guests to our doorsteps due to light pollution. Lights attract bugs and bugs attract bats.

Astronomers from amateur to professional can all agree that light pollution is a great disturbance. Before even viewing a star astronomers without an enclosure cannot expect to have full dark adaption at night. The tools of astronomy are also plagued by light pollution. For instance, the Mt. Wilson Observatory just outside of Los Angeles is now operating at 11% of its original capacity due to the glowing L.A. night sky. While some stars may be visible in areas of high light pollution galaxies and nebula are greatly dimmed and very difficult to see even with advanced telescopes. New observatories are increasingly being constructed in remote areas in order combat light pollution but remote construction brings higher costs.

Limiting magnitude can be described as the faintest apparent magnitude of a celestial body capable of being detected and dependent upon equipment. Light pollution has a direct and sustained impact on the limiting magnitude in a given area. The limiting magnitude of the human eye under a completely dark sky is somewhere in the range of 7.6-8.0. At the other side of this scale, imagine yourself staring up at the night sky in a brightly lit inner-city setting. The limiting magnitude of your eye has been reduced by fifty percent to 4.0 or less. That comparison is simply applied to eyeball astronomy though, what about astronomers looking to make an observation. Under a dark sky with a 32 centimeter reflecting telescope you might just make some observations at the 18th magnitude. Again, we travel to the city where you set up your scope and find that you will only be making observations at the 13th magnitude.

For those in areas affected by light pollution there are some methods of circumventing it. Astronomers often employ narrow or high-band filters that do not allow light of certain spectral lines to pass through a telescope. The spectral lines targeted are those emitted by common vapor lamps including mercury and sodium. Though a good tool, these filters do limit the use of higher magnification.

If you wish to calculate how much light pollution will affect your astronomy work there is a simple equation to employ. The equation, I=0.01Pd-2.5 where I is the increase in sky glow, P is the population of the targeted city and d is the distance to the center of the city, works very well. This law is commonly referred to as Walker’s Law. Merle Walker proposed this relation after taking measurements of sky glow in several California cities. If you used this calculation and yielded a value of .03 that would mean that at the midway point between the horizon and zenith angle in the direction of the city the current sky would be 3% brighter than the natural background.

It is easy to see that combating light pollution would be of great benefit to society in general, the cost savings alone are staggering. Every year we waste one billion dollars lighting the night sky. Remediation of this problem is not as difficult as one might think; in fact, light pollution is the easiest of all forms of pollution to fix. Replacing old style lamps that radiate light in all directions with lamps that focus light downward is one remediation tactic. Also, we have to realize that lighting is not always necessary and we should take steps to remove lighting where it is not needed. Changing output is another effective method. Extremely bright bulbs are used in a number of lighting applications where they are not needed, limiting energy output not only reduces light pollution but also saves money.

We often light outdoor areas without a thought as to what we are losing. We may gain a little extra ease of night time navigation but we lose light at the same time. The light we lose is the light from nebula, galaxies and stars. This light has traveled a great distance, often many light years. This light has traveled those great distances through the vast reaches of outer space. This light ends its journey within our atmosphere at the hands of our lighting. Light pollution is a problem we have created but a problem that we can fix. Take a moment to look at the heavens through a dark sky and ask yourself if it is worth saving. My answer is yes.


Posted by jcconwell in Astronomy, Observatory.
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30" RC Astroscope

Yerkes Skynet Night Registration

You are invited…


Skynet Night

Yerkes Observatory event Friday Feb. 24th – 7:00 PM


In 2012, Yerkes will be engaged in a series of fund-raising events to support the restoration and upgrades of Yerkes telescopes and support funding for Yerkes Education Outreach programs. On Friday evening February 24th, Yerkes will host the first of these events.

Supporting SKYNET and Yerkes telescopes

Funds from this first event will be used specifically to upgrade the mirror coating and operation of the Yerkes 41″ reflector, and to support the redesign of the optics of the reclaimed Hands-On Universe 30” telescope by Robert Holmes of the Astronomical Research Institute. Both of these telescopes are operable through SKYNET (http://skynet.unc.edu/), a world-wide network of telescopes, used by scientists, and teachers and students associated with our Yerkes Education Programs and our Collaborators, including Hands-On Universe (HOU) and International Asteroid Search Campaign (IASC).

Limited participation, register now!

Participation will be limited to 100 guests; cost $50 per person. There will be several scientists, engineers, educators and students attending to mingle with the guests to discuss SKYNET, our participation in SKYNET and the plans we have to restore Yerkes telescopes. If weather permits, guests will also be invited to do some stargazing through the Yerkes great refractor. Wear warm clothes (domes are not heated) and shoes appropriate for climbing narrow stairs; flashlights are suggested as well.

It is our hope to find benefactors among the guests who will be interested in a contribution beyond the initial $50.

Name___________________________________________ Address___________________________________________ City______________________________ State _____________ Zip__________ YES, _____________ Person(s) will attend @ $50 per person

Check enclosed for $_________________

Checks payable to: University of Chicago, Yerkes Observatory
Send checks to Yerkes Observatory, 373 W. Geneva Street, Williams Bay, WI 53191 Additional information, phone: 262-245-5555, fax: 262-245-9805
You may also register online at http://astro.uchicago.edu/yerkes/yo_feb24/index.html 

Astronomy Club Tonight: Gamma Ray Bursts November 3, 2010

Posted by jcconwell in Astronomy, Gamma Ray Bursts.
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Astronomy Club tonight in Room 2153, at 8:00 PM in the Physical Science Building. Dr J Conwell will be talking about Gamma Ray Bursts; the most violent explosions since the big bang.

Earth-sized Exoplanet is in Nearby Star’s Habitable Zone! September 29, 2010

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Gliese 581d

(From Universe Today) An enticing new extrasolar planet found using the Keck Observatory in Hawaii is just three times the mass of Earth and it orbits the parent star squarely in the middle of the star’s “Goldilocks zone,” a potential habitable region where liquid water could exist on the planet‘s surface. If confirmed, this would be the most Earth-like exoplanet yet discovered and the first strong case for a potentially habitable one. The discoverers also say this finding could mean our galaxy may be teeming with prospective habitable planets.

“Our findings offer a very compelling case for a potentially habitable planet,” said Steven Vogt from UC Santa Cruz. “The fact that we were able to detect this planet so quickly and so nearby tells us that planets like this must be really common.”

Vogt and his team from the Lick-Carnegie Exoplanet Survey actually found two new planets around the heavily studied red dwarf star Gliese 581, where planets have been found previously. Now with six known planets, Gliese 581 hosts a planetary system most similar to our own. It is located 20 light years away from Earth in the constellation Libra.

The most interesting of the two new planets is Gliese 581g, with a mass three to four times that of the Earth and an orbital period of just under 37 days. Its mass indicates that it is probably a rocky planet with likely enough gravity to hold on to an atmosphere.

For more go to the rest of the article at Universe Today.

Open House at the Observatory Tonight! September 24, 2010

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EIU Observatory

It’s the last Friday of the month and the first Friday of Autumn! Time for the open house. Weather cooperating the target for tonight is Jupiter. It’s in opposition to the sun (in the sky ~180 degrees from the Sun), which mean it is also closest to the Earth. So Jupiter will not look any better until next year. So come on out, viewing begins at 8:30.

Attendees will be able to look through the observatory’s state-of-the-art, 16-inch Schmidt-Cassegrain telescope. Even if it’s cloudy, the observatory will be open for tours.

Eastern’s observatory is located southwest of the Campus Pond. A map is available online at http://www.eiu.edu/~physics/campusmap.pdf.


Posted by jcconwell in Astronomy, physics.
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Tonight the Astronomy Club is having the first meeting of the semester.  We will be meeting in the usual spot, room 2153 in the Physical Sciences Building, at 8pm.  We will discuss our agenda for this year and plan out any events that people would like to do.  Tyler will talk a little bit about the work he did at the observatory and Yerkes this summer, and talk about his plans with continuing that through the semester.

See you there,

Josh Hawkins, President

Hamburgers Tonight! August 26, 2010

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Yes it’s really called Gomez’s Hamburger Nebula. A perfect picture for the first Astronomy Club meeting tonight. To learn more about celestial hamburgers, and to eat a few terrestrial ones, along with brats, boca burgers, and and other goodies; come to Dr. Conwell’s house (921 6th street) at 5:30PM,  for the first meeting and cookout of the astronomy club. The Society of physics student will also be there!  If you are new to campus and just curious now’s the perfect time!

NEW PODCAST:Where Do We Come From? July 19, 2010

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This episode of “365 Days of Astronomy” is sponsored by the Physics Department at Eastern Illinois University: “Caring faculty guiding students through teaching and research” at www.eiu.edu/~physics/.

Description: Carolyn Collins Petersen, The Spacewriter, muses on our cosmic origins, starting with our home here on Earth. It’s a story that takes you out to the most distant reaches of the universe.


Bio: Carolyn Collins Petersen is a science writer and show producer, as well as vice-president of Loch Ness Productions, (http://www.lochnessproductions.com/index2.html) a company that creates astronomy documentaries and other materials. She works with planetariums, science centers, and observatories on products that explain astronomy and space science to the public. Her most recent projects range from documentary scripts, exhibits for NASA/JPL, the Griffith Observatory and the California Academy of Sciences, to video podcasts for MIT’s Haystack Observatory and podcasts for the Astronomical society of the Pacific’s “Astronomy Behind the Headlines” project.

Congratulations to Dr. Kasey Wagoner!! June 4, 2010

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Dr. Kasey Wagoner

Congratulations to Kasey Wagoner for recieving his Ph.D in physics from Washington University in St. Louis this spring. Dr.  Wagoner received his BS in physics here at EIU. He will be spending the next two years as a post-doctoral fellow in the physics department at Washington University. He was in my freshman astronomy class in 2001 when I managed to convince him that physics and astronomy were a lot more fun than accounting! The smile proves I was right!

Congratulations to the Physics class of 2010! May 9, 2010

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Yesterday May 8, was the spring commencement at Eastern Illinois University, we have pictures of the five graduates who walked in the spring, there are two more students who were not at the commencment. First and foremost my son David Conwell

Herding people after commencement is somewhat like herding cats, but we did get manage to get most of them in one group photo.

David Conwell , Nick Prorok , Alicia VonLanken, Tom Malkowski

Last but not least Bill Wolf! Bill was pulled out of line to make the seating even, otherwise we probably could have gotten everyone group photo. Bill and Alicia VonLanken are the first two students to graduate from Eastern in the Physics -Astronomy option.

Bill Wolf