Calculation Of A Big Boom

Credit: NASA/CXC/JPL

Infrared image of Tycho's Nova which is the remnant of Type Ia supernova.

Because of the work of our guest last Wednesday, Dr. Ryan Foley, and some events earlier this year, I feel that it is time to study something about the supernova.

When a high-mass star reaches the end point of its life, it explodes into a big ball of flame called supernova.  Astronomers have calculated that around 3 massive stars will go through a special Type Ia supernova every thousand year in our Milky Way galaxy. In other words, within distance of several thousand light year from Earth, a fair amount (20+) of stars is about to give a big boom. The picture above shows a nice picture of the remnant of supernova. It is beautiful to observe from some distance but we don't want to get too close to the explosion. That is why we are trying to determine when a star will blow up.

Did Baptistina Asteroid Cause Dinosaur's Extinction?

Credit: www.tickreel.com

There are many theories behind the extinction of dinosaurs 65 million years ago. One theory is that an impact of an asteroid causes it but no one is sure what type or how the asteroid heads to the Earth. From the study in 2007 by using data from observatories in visible-wavelength range, the culprit is the type of asteroid called "Baptistina."

Stellar Properties From Afar

by Mee Wong-u-railertkun, Nathan Baskin, John Pharo, David Vartanyan

Credit: apod.nasa.gov Info about this picture is presented below.

We present the solution to the first question from the worksheet "Stellar Properties From Afar."

We are given the following information about the sun,
1) The angular diameter of the sun is 0.5 degrees.
2) The astronomical unit (AU), distance between the Earth and the Sun, is approximately 1.5 * 10^13 cm.

Determining the Astronomical Unit from Mercury's Transit

by Mee Wong-u-railertkun, John Pharo, David Vartanyan

We were given a picture of Mercury's transit taken by NASA's Transition Region and Coronal Explorer (TRACE) which is a polar low-Earth orbit satellite. The picture looks like this.

Planet Surface Temperature

by Mee Wong-u-railertkun, John Pharo, David Vartanyan

Abstract

We investigate the relationship between the energy emitted from a star and the surface temperature of a planet. We assume that a star and a planet are perfect spheres and they are perfect blackbodies, i.e. power absorbed equals to power emitted. Moreover, they radiate isotropically. Later, we compare between the theoretical surface temperature of the Earth with the real data.

A Brief History of Palomar Observatory

Credit: www.astro.caltech.edu/palomar

Since we, Ay20-ites, are going to Palomar Observatory tomorrow (Sunday 10/16), I should dig out some information before hand. Inside the big dome, the temperature is kept around 30 to 40 degree so we better bring a jacket!

The Palomar Observatory is located in north San Diego County, California around 100 miles south of Caltech. Its coordinates are 33 degree 21' 21''N and 116 degree 51' 50'' W with the altitude of 5618 feet or 1712 meter. It is a world-class instrument for astronomical research that is owned and operated by the California Institute of Technology. The observatory is consisted of five telescopes including the 200-inch telescope.

Recalling Blackbody Radiation

by Mee Wong-u-railertkun, John Pharo, David Vartanyan

Abstract

We present the solution to the Black Body Radiation worksheet problem 1, from week 3, recalling basic ideas of black body radiation from energy density to specific intensity and flux. In the first part, we investigate the contradiction of the units of energy density. In order to convert from energy density to intensity and flux, we have to study the concept of solid angle. These equations are used frequently in astronomy.