Sunday, February 28, 2010

Feb 24 Recap

Some topics we talked about:

1. Astronomers found Type Ia SNe born differently in some elliptical galaxies than we originally thought. Read the Nature paper here.

2. Four dwarf galaxies relatively nearby (few hundred million light-years away), are in the process of merging, which usually happened billions of light-years away. Read the story here.

3. By studying the age and chemical properties of globular star clusters in our galaxy, astronomers believe at least a quart of star clusters are invaders from other galaxies. Read the story here.

4. Primitive stars have been found outside Milky Way galaxy. Read the news release here.

Monday, February 15, 2010

Feb 10 Recap

This week's journal club was hosted by Michael Bietenholz. Some highlights were:

1. A numerical simulation shows that, even a galaxy like ours should host hundreds of intelligent civilizations, the civilizations like us are likely exist one at a time. Read the article here. If you like to know about the Rare Earth hypothesis mentioned in the article read the paper here.

2. "Seven-Year WMAP Results: No, They're NOT Anomalies", read the article here, or try your hand to find interesting patterns in WMAP here.

3. Radio astronomers have found a supernova explosion with properties similar to a gamma-ray burst, but without seeing any gamma rays from it. Read the press release here.

4. Astronomers in the Netherlands catch supernova, observe relativistic expansion. Read Nature paper here.

Wednesday, February 3, 2010

Feb 3 Recap

This week's journal club was hosted by Prof. Paul Delaney. Some of the topics we discussed were:

1. This week NASA announced their new budget plan. News stories about Constellation has been cancelled, and NASA gave the human spaceflight to 5 commercial companies. Read the details of NASA budget at its homepage.

2. Hubble Space Telescope caught a head-on collision between two asteroids. Read the news here.

3. "What else is out there?" appears in the March edition of Sky & Telescope, discussed about whether earth-size objects exist in the Kuiper Belt, and the detection of interstellar comets.

4. Study of W33A, a Massive Young Stellar Object (MYSO), shows that massive stars form in much the same way as in smaller stars. But planets is less likely to be formed  around massive stars. Read the story here.

5. A stellar-mass black hole is found in a binary system in NGC300. It is the second most massive (15 solar masses), and the most far-away (outside the Local Group) stellar-mass black hole ever found. Its company is a Wolf-Rayet star. Read the story here.