Mar 3 - Las Atmósferas Estelares

(This was our 3rd Annual Spanish-Language Lecture)

Turns out the Sun has an atmosphere, albeit very different from Earth’s. Alejandro Núñez, a graduate student at Columbia University, unveiled what is known about this gaseous envelope, layer by layer. He further described how a flotilla of space probes is helping scientists clarify some remaining mysteries by continuously gathering data from all angles and wavelengths. The most vexing of these unsolved questions is how the corona -the outer layer of the Sun’s atmosphere- can be hundreds of times hotter than the photosphere -its visible surface-, reaching temperatures in excess of a million degrees Celsius. While a detailed description of the heating mechanism still needs to be developed, it seems to be linked to the complex interaction between the Sun’s magnetic field and its atmospheric plasma.

Turns out the Sun is also a star. Thus, we can extrapolate what we learn about the Sun to other stars. As Alejandro explained, we need to do so with caution, for different stars can have diverse levels of magnetic activity. He illustrated this with a discussion on how the red dwarf at the core of the recently discovered multiple planetary system Trappist-1 seems to be much more active than our Sun, and the consequences that this could have for the habitability of the planets orbiting it.

This was the Spanish public lecture of this season, and the audience had the opportunity to stargaze at the Rutherford observatory on Pupin Laboratories’ roof after the talk. The night was cold and partly cloudy, but we managed to get a glimpse of some objects like the Moon and Mizar through some clearings.

-- Jose Zorilla (graduate student) 

May 20 - La Escalera de Distancias Cósmicas

Our last public outreach night of the spring semester was a special version, as the whole event was conducted in Spanish. Although the event was targeted to the Spanish-speaking community of New York, the audience was mixed, as some non-Spanish speaking attendees chose to skip the talk and head directly to the roof top to observe the sky. We were lucky enough that night to have bright Jupiter and the Moon easily accessible from our telescopes.

José Zorrilla, a graduate student in the Astronomy Department at Columbia University, gave a talk titled “La Escalera de Distancias Cósmicas” (“The Cosmic Distances Ladder”), in which he explained some of the ideas and methods used in astronomy to determine distances across the universe. He began by explaining the concept of trigonometric parallax and how astronomers use it to measure the distance to nearby stars. He then talked about astronomical objects known as standard candles, such as supernovae and some types of variable stars. These, he explained, can be used to measure much greater distances, to galaxies in the vicinity of the Milky Way and beyond. Lastly, José talked about redshift as a way to measure distances to the most faraway galaxies in the universe. To put it all together, José explained how the different methods rely upon others to determine distances to the most remote objects we know in the universe, hence the term “ladder”. He also pointed out that the discovery of new distance measuring methods has led the revolution in our understanding of the universe and its true extent.

-- Alejandro Núñez (graduate student)

May 8: “Al Otro Lado del Espectro” (At the Other Side of the Spectrum)

Our last public outreach night of the semester took place on May 8th and it was a very special one since it marked the first Spanish-speaking outreach event in many years. The whole event was conducted in Spanish, including announcements, the presentation, and the activities that took place afterward. It was a mixed audience, consisting of regular attendees, people interested in practicing their Spanish, and Spanish-speakers in the community.  

Alejandro Núñez, a graduate student in the Astronomy Department at Columbia University, gave a talk titled "Al Otro Lado del Espectro" ("At the Other Side of the Spectrum"). Alejandro started the talk by describing the wave nature of light, and introduced concepts such as frequency and wavelength. Then he showed several spectacular images of celestial objects at different wavelengths, starting from the long-wavelength radio waves, all the way to the short-wavelength gamma rays. He included many images of the Sun, other planets, and our Milky Way.  He concluded by showing us the different telescopes capable of observing the different parts of the electromagnetic spectrum.

After the talk, many audience members went to the roof to see Jupiter and M3 through the telescopes, where they had the opportunity to talk with the Spanish-speaking volunteers.  Some  attendees stayed in the lecture hall asking Alejandro a few more questions. In addition, undergraduate student Gladys Velez-Caidedo  showed several movies on the 3D wall.  It was a good turnout and we expect to have similar events in the future.  

-- Ximena Fernandez (graduate student)