The “Noon At The Nerman” program connects artwork throughout the Johnson County Campus to the scholarly activities of the faculty here on campus. This past month, Dr. Doug Patterson, Professor of Astronomy, was invited to lead off the Fall Semester with a discussion of the Galileo’s Garden sculpture that now resides on the south lawn in front of the new Sustainability Building.
During Dr. Patterson’s talk, he refered to Prof. Paul Tebbe’s work with the analemma when the Galileo’s Garden sculpture was next to where the fountain between the SCI and GEB buildings is now. Thanks to Dr. Anita Tebbe, we rediscovered a video of Prof. Tebbe’s public talk demonstrating the analemma and the overlay he and his students made for the sculpture.
Our public open house for the Transit of Venus was surprising for a few different reasons. First, we had clear skies! Usually, when we plan a public observing events, that’s the signal for clouds to rush in from all directions and hover over the Paul Tebbe Observatory. Our second surprise after having clear skies was to have hundreds of people lined up to take a look at the Sun and Venus! Normally, we have a 50 or so people turn out for one of our events. For this past Spring’s Evening With The Stars program, we were elated to have 150 people come out. This past Tuesday, we EASILY had double that number if not more! People from the college and the community lined up down the stairwell from the roof and all the way down the hall on the 4th floor of the CLB, and all evening long, the line never shrank!
We apologize to those who weren’t able to make it to the roof before sunset, but for those who did, we got to see a fantastic and rare sight, Venus eclipsing the Sun! Venus is nearly as large as the Earth, and nearly four times the size of our Moon, but since it’s much further away from us, it’s angular size in the sky is much smaller than the Moon’s so when Venus passed directly between us and the Sun, it didn’t block the entire disc of the Sun, but only a part of it. Since Venus doesn’t orbit in precisely the same plane around the Sun as the Earth, it’s very rare that Venus ever passes directly between us and the Sun. Usually, Venus misses the Sun by a degree or two, but when the geometry is just right, we’re treated to a transit event like we were able to witness last Tuesday evening.
The dark disc of Venus passing across the face of the Sun wasn’t the only thing that visitors were able to see when they came to the Paul Tebbe Observatory. With the two different types of filters we were using to observe the Sun, we were able to see a number of sunspots, and some solar prominences, hydrogen and helium gas caught up in large magnetic arcs above the solar surface. After sunset, many stayed around and were able to see Mars and Saturn through the telescopes as well as the double-star Alberio.
All in all, it was a fantastic evening and we were overwhelmed and humbled by the magnitude of the turnout. We would like to thank everyone who came out to join us and look forward to our next observing event! To see more photos from the event, check out our page on Facebook.
The JCCC Science Division presents an EVENING WITH THE STARS to be held on April 28th at 7:00pm in the Craig Auditorium, GEB 233.
Dr. Thomas Armstrong, Retired Professor of Physics from the University of Kansas and Principle Scientist at Fundamental Technologies, LLC, will give a talk on the history of space exploration, Human History in Space, looking at the major events in space exploration and discoveries that shape our understanding of Earth, the Solar System, the Galaxy, and the Universe as well as discussing presently understood challenges and opportunities in space for present and future generations.
After the talk and weather permitting, we will have several telescopes set up to observe the night-sky at the Paul Tebbe Observatory on the roof of the CLB. Some objects of note that will be viewable are:
The corn is starting to dry out, so it must be time for the Fall semester to start up again. Here at JCCC, though, the work doesn’t stop just because its Summertime. This past summer term, I had an honors student that worked on astrophotography and differential photometry. Both were fun projects, and I’ll write more about the variable star photometry later. For now, let me show off some of the excellent images G. W. Francis took with our SBIG ST-8 CCD camera and his own Nikon D40.
Every Monday evening in June, it seemed, was cloudy, so we decided to take advantage of a sunny afternoon and image the Sun using an H-alpha filter. This filter only allows the one wavelength of red light emitted by hydrogen atoms which enables us to see features like the prominence shown above.
GW mounted his D40 onto the piggyback mount of our Celestron 8″ SC telescope and tried to take an image of the constellation Ursa Major. Most of what he got was the reflected light from the sodium vapor lamps in the parking lot. This was the last night of observing at the college. The light pollution was just too much for us.
GW mounted his Nikon D40 on a tripod and pointed it northward, centering Polaris in the field of view and collected 21 images each with a 30-sec exposure. By rotating and aligning each image, a detailed view of the Northern Night Sky is revealed. When the images are not rotated, but simply stacked and merged together, the rotation of the Earth becomes apparent as the stars leave trails through the sky. Notice that Polaris, which is very close to the North Celestial Pole, remains nearly fixed in place.
Before settling down onto the program variable star for the evening, the we targeted several Messier objects. M57, the Ring Nebula, is a planetary nebula. A star, not unlike our Sun, threw off its outer layers as it died leaving behind an expanding shell of gas and a small but staggeringly hot white dwarf in the center.
M16, The Eagle Nebula, made famous by the Hubble Telescope’s image Pillars of Creation, had to be imaged by peeking through the gaps in a maple tree near where we had setup the telescope. The location was chosen for optimum viewing of the variable star DY Her, not M16, but we got lucky. In the image you can make out the famous pillars in the top center of the image.
M13, the Great Cluster in Hercules, is one of the closest (relatively speaking) globular clusters to our planet. This dense cluster is home for around a million ancient stars.
Rather than using the SBIG ST-8 CCD camera, I opted for my Nikon D90 for these photos. In some respects its better, in other ways not so much. First stop: The Sun.
In this image, you can see the Sun’s chromosphere and a small prominence on the left side of the image. The camera doesn’t have the resolution nor dynamic range of your eyeball, so cool though this may be, nothing substitutes for seeing the Sun live. This image was taken through a DayStar H-alpha filter threaded to the back of our 12″ Meade on the roof of the CLB with my D90. I’ve tried doing solar imaging with the SBIG camera, but even at the fastest shutter speed, the image saturates. Even in the above image, the disc of the Sun is overexposed in order to make the chromosphere visible.
Alberio is a nice double star in the constellation of Cygnus. If you have a pair of binoculars, this is an easy target. The color difference between the two stars is due to their different temperatures. The bright blue star is extremely hot where as the yellow star is cooler (relatively speaking) with a temperature closer to that of our own Sun. This image is a single 30″ exposure with the D90 set at ISO3200. The noise isn’t too bad, but being a single shot, there’s more noise and less detail than one could get by taking multiple images and combining them. I’ll try that some time soon. With the D90 as opposed to the SBIG, the colors of the two stars are really easy to capture. With the SBIG, one would have to take three separate images through a red, a green, and a blue filter and combine them to form the color image. Doable, but definitely more work.
This image of the Great Cluster of Hercules, M13, is a single 30″ exposure like the image of Alberio, but with the much dimmer object comes a lower signal-to-noise ratio. Imaging objects like this is where the SBIG becomes vastly superior to a digital SLR like the D90. As with the Alberio image, this image could be improved by combining multiple exposures.
The Evening With The Stars this spring had a great turn out. Thanks to all who came out. Leo gave a great talk, and I’ve heard from many of the attendees that they really enjoyed the evening. Unfortunately, the weather was not as cooperative and clouds ruined our planned observing. We’ll try again in the Fall when we have our EWtS event again. Here are some pictures from the evening.