Science Seminar April 3

Science Seminar Series

Presents

Naomi Schwartz

Doctoral student, Columbia University

Understanding the causes and effects

 of fire in the Peruvian Amazon

In recent years, wildfire activity has increased across the Amazon. In the past, fire was very rare there, so these changes could have big effects on biodiversity, ecosystems, and the carbon cycle. Most fires in the Amazon are started by people, either intentionally, through the use of fire for land management, or accidentally. Especially during drought years these fires can burn out of control into nearby forests. Naomi Schwartz is a Ph.D. student in ecology, evolution, and environmental biology at Columbia University. Her work uses a combination of ground and satellite measurements to understand the causes and effects of these fires in the Peruvian Amazon. She is especially interested in understanding the relationships between human activities and fire occurrence, and the effects of fire on secondary forests.

Wednesday, April 3

7 pm

Bronxville High School Auditorium

Closest Star System Found in a Century

                According to a paper that will be published in Astrophysical Journal Letters, the third-closest star system to the Sun is discovered. The duo is the closest star system discovered since 1916. The discovery was made by Kevin Luhman, an associate professor of astronomy and astrophysics at Penn State University and a researcher in Penn State's Center for Exoplanets and Habitable Worlds.  By combining the detections of the star system from the various surveys, Luhman was able to measure its distance via parallax, which is the apparent shift of a star in the sky due to Earth's orbit around the Sun. He then used the Gemini South telescope to obtain a spectrum of it, which demonstrated that it had a very cool temperature, and hence was a brown dwarf, which is star that are too small in mass to ever become hot enough to ignite hydrogen fusion. As a result, the newly discovered system is very cool and dim, resembling a giant planet like Jupiter more than a bright star like the Sun.


                The star system is named "WISE J104915.57-531906" because it was discovered in a map of the entire sky obtained by the NASA-funded Wide-field Infrared Survey Explorer (WISE) satellite. It is only slightly farther away than the second-closest star, Barnard's star, which was discovered 6.0 light years from the Sun in 1916. The closest star system consists of Alpha Centauri, found to be a neighbor of the Sun in 1839 at 4.4 light years, and the fainter Proxima Centauri, discovered in 1917 at 4.2 light years. “The distance to this brown dwarf pair is 6.5 light years -- so close that Earth's television transmissions from 2006 are now arriving there,” Luhman said. “It will be an excellent hunting ground for planets because it is very close to Earth, which makes it a lot easier to see any planets orbiting either of the brown dwarfs. Since it is the third-closest star system, in the distant future it might be one of the first destinations for manned expeditions outside our solar system,” Luhman said.


                 I think it’s an excellent article about the new discovery of the new star system.  The author included a lot of quotes from professor Luhman, which made it well-informed while interesting.  There are also descriptions of how Luhman found out that it’s 6.5 light years from Sun— parallax, which is closely related to the topic we are studying now.  It increases my knowledge on the classification of dwarf stars.  Overall, I really enjoyed reading the article, and I hope there are further discoveries soon.

“Radiation ring around Earth mysteriously appears, then dissipates”

            This article was very interesting, and insightful. It talks about the rings of energetic charged particles that float high above the Earth’s surface. Normally there are two of these rings floating above Earth, and previous to last September, scientists did not know there could be a different number of rings. Normally, the inner-most ring in made mostly of protons and some electrons, and the outer zone is dominated by electrons. On August 30, NASA launched twin space probes to study the fine details of disruptions in these rings, and just days after the probes were launched, researchers led by Daniel Baker watched a third ring grow between the two existing ones. After a month, this ring disappeared, but so did the outer ring, and in the following months the outer ring returned.

            This discovery provides some very important, previously unknown information about these rings of high-energy particles.  In the words of Yuri Shprits of the University of California, “this most important region of space where most of the satellites operate presents us with new puzzles.” This discovery, and the monitoring of these rings by NASA’s space probes, provide some extremely important information that will prevent the loss of some satellites.

            I thought this article was very interesting, and was made pretty well. One thing that I wish was done differently was that I would have liked there to be some more information about the composition of the rings, and possibly a little more information about the new ring that appeared. Overall, I liked how the information in this article was presented, and I thought it was very informative.

Solar System Planet Projects

This quarter's project assignment for the Core Earth Science students was to prepare a PowerPoint Presentation on a planet or heavenly body within our solar system.

Alberghine Frayne Venus by Charles Ippolito

Connor Elder Uranus by Charles Ippolito

Drygulski Neptune Presentation by Charles Ippolito

Giangola Mroz Mercury by Charles Ippolito

Grant Huang Io by Charles Ippolito

Huncke SUN by Charles Ippolito

Louka Owen Jupiter by Charles Ippolito

Lynch Shultz Earth Ppt by Charles Ippolito

McCann Walsh Mars by Charles Ippolito

Minoli Redpath Saturn by Charles Ippolito

Chrappa Gay Mars by Charles Ippolito