November 2015: Picture of the Month


The Pelican Nebula, also known as IC 5070, is an H II region that is slowly being divided from the larger North America Nebula by a molecular cloud of dark dust. The Pelican is often studied due to its particular mix of active stars formation and evolving gas cloud. This picture was produced in three specific colors – each associated with light emitted by sulfur, hydrogen and oxygen. The bright orange color on the right, known as the ionization front, is due to the fact that the light from young, energetic stars is transforming the cold gas into hot gas. Although this nebula got its name due to its resemblance to a pelican, millions of years of now, it might no longer be known as the Pelican, as the balance and placement of stars and gas will leave something quite different.

For more information, check out APOD.


Star Talk: Seeing Beyond Red with Cool Technology


“Seeing Beyond Red with Cool Technology”, presented by Dr. Suresh Sivanandam

Abstract: Humans often don’t realize that they can sense more than visible light. They feel infrared radiation as heat, which is also another form of light. Over the past few decades, there has been an explosion of technological innovation in the detection of infrared light. This has opened up huge discovery spaces in astronomy. It has enabled us to see the effects of our galaxy’s central supermassive black hole and take pictures of planets in nearby star systems. Stardust in galaxies also lights up in the infrared, allowing us to track the evolution of galaxies from very early times. The technology required to detect infrared light is quite unique and presents difficult engineering challenges. I will present an overview of the great new discoveries in infrared astronomy and the associated technological breakthroughs that have ushered in this new and exciting era of astronomy. I will end with the pinnacle of space engineering, the James Webb Space Telescope, which is going to be the largest space telescope ever built. When this telescope is launched in 2018, it is going to completely revolutionize astronomy as we know it.


October 2015: Picture of the Month

This is one of the two global maps of Jupiter captured on January 19, by observing the ten hours rotation of the giant gas planet with the Hubble Space Telescope. The all-planet projection represents the first of a series of planned annual portraits by the Outer Planet Atmospheres Legacy program. An interesting feature in the picture: the Great Red Spot, the famous long-lived storm with the wind speed of 300 miles per hour, seems to be decreasing in size (if you compare the original two pictures which can be viewed by going to the APOD site below), although it is still large compared to planet Earth.

For more information, check out APOD and NASA.


Star Talk: Thermonuclear Supernovae


Thermonuclear Supernovae and the Quest to Understand Why White Dwarfs Explode by Professor Marten van Kerkwijk

If a carbon-oxygen white dwarf explodes, it will look like a type Ia supernova, with most of the carbon and oxygen fused to silicon- and iron-group elements. But it remains unclear both under what physical conditions the explosions are triggered and in what astronomical configurations these conditions are brought about. What is clear is that the standard picture, in which unstable fusion is ignited in white dwarfs that approach or are made to exceed the largest possible (Chandrasekhar) mass, can easily reproduce neither the rates nor the properties of normal type Ia supernovae. I will discuss these and related conundrums, describe our efforts to see if supernovae could result generally from mergers of similar-mass carbon-oxygen white dwarfs, and try to summarize possible observational tests.

Marten van Kerkwijk is a Professor of Astronomy and Astrophysics at the University of Toronto, with interests covering much of astronomy but a focus on compact objects (“stellar corpses”), stars and binaries, their structure, formation, and evolution, and their use to infer fundamental physical properties. A major focus of his career has been to use neutron stars to study high-density and high field-strength physics, in conditions out of reach of terrestrial experiment (and theory, as yet), and to solve associated astronomical puzzles. More recently, he has turned to a different quest: to understand what triggers thermonuclear supernovae.


September 2015: Picture of the Month


These dark streaks seen on Mars, called recurring slope lineae, are inferred to have been formed by flowing liquid water. Recently, by using an imaging spectrometer on NASA’s Mars Reconnaissance Orbiter (MRO), scientists have detected signatures of hydrated salts on slopes where the mysterious streaks are seen. These streaks appear to flow over time; flowing down slopes during warm seasons and fading in colder seasons. The findings of hydrated salts hints the idea that the freezing point of a liquid brine is lower, making it possible for shallow subsurface flow.

For more information, click HERE.