How Rockets Work

Audience: Educators
Grades: K-12


This section of the Rockets Educator Guide explains Newton's Laws of Motion, which support the basic principles of rocketry.

How Rockets Work  [372KB PDF file]

How Rockets Work is part of the Rockets Educator Guide.

Laboratorium Astrofisika

Astrophysics Laboratory
 

  “Life is either a daring adventure or nothing.”

"Hidup adalah petualangan yang membutuhkan keberanian, bila tidak itu bukanlah hidup."

Harvard-Smithsonian Center for Astrophysics
60 Garden Street, Cambridge, MA 02138

H-R Diagram of M67 using the Clay Telescope

 
 

Instructors: Allyson Bieryla and Jonathan Grindlay

The Clay Telescope is located on the roof of the Science Center. It is a 16" telescope equipped with a CCD (charged coupled device) imager. This project is divided into three main parts. First you will learn to use the telescope to observe and image the open cluster M67 in B and V filters. We will probably need no more than three nights of observing to accomplish this, but that is just an estimate. We will then learn how to process the images using IRAF (Image Reduction and Analysis Facility) software. 

This software will enable us the tools to reduce the data, subtracting away the inherent biases of observing. We will also use IRAF to do the actual photometry to determine the magnitudes of the stars in the cluster in both B and V fields. Finally we will create an Hertzsprung-Russell diagram, which plots the V magnitude vs. B-V magnitude. This shows where the stars in the cluster are on the main sequence. From this diagram, we can estimate the cluster's age and determine the approximate distance to the cluster. Also, knowing the angular width of the CCD image and the distance to cluster, we can approximate the number of stars in a single image to get a rough density of stars in the cluster. 

Laboratory Astrophysics

Science is successful because the physical laws we discover on Earth work everywhere and every when. We use laboratory experiments to expand our understanding of physical processes and then apply these results to the processes throughout the Universe. In some cases laboratory experiments can reproduce similar physics. For example, highly charged plasmas can be created in the laboratory to study the collisions between electrons and ions that occur in the hot solar corona. In other cases, such as in the extreme environments of black holes, we cannot reproduce the conditions. However, even in those cases, the pattern of observed spectral signatures allows us to identify the species and determine some of the physical conditions and processes. Spectral features observed in the solar corona are also observed from black hole sources.  

Useful Link

• ADS Bibliographic databases, an essential tool of modern astronomers
  
  
• astro-ph Astronomy e-prints
  
  
• Astronomy Picture of the Day - never disappoints
  
  
• Chandra Coordinate Conversion and Precession Tool
  
  
• Clear Sky Clock - best local cloud forecaster
  
  
• SkyView - virtual telescope
  
  
• AstroWeb - Guide to astronomy on the internet
  
  
• AAS American Astronomical Society
  
  
• Handbook of Space Astronomy and Astrophysics by Martin V. Zombeck
  
  
• Research links from Harvard Department of Astronomy

 

COSMIC RAY ACCELERATION AT BLAST WAVES FROM TYPE Ia SUPERNOVAE

By: HYESUNG KANG

Department of Earth Sciences, Pusan National University, Pusan 609 -735, Korea

E-mail: hskang@pusan.ac.kr

(Received November 10, 2006; Accepted December 6, 2006)

ABSTRACT

We have calculated the cosmic ray (CR) acceleration at young remnants from Type Ia supernovae expanding into a uniform interstellar medium (ISM). Adopting quasi-parallel magnetic fields, gasdynamic equations and the diffusion convection equation for the particle distribution function are solved in a comoving spherical grid which expands with the shock. Bohm-type diffusion due to self-excited Alfv´en waves, drift and dissipation of these waves in the precursor and thermal leakage injection were included. With magnetic fields amplified by the CR streaming instability, the particle energy can reach up to 10 16 Z eV at young supernova remnants (SNRs) of several thousand years old. The fraction of the explosion energy transferred to the CR component asymptotes to 40-50 % by that time. For a typical SNR in a warm ISM, the accelerated CR energy spectrum should exhibit a concave curvature with the power-law slope flattening from 2 to 1.6 at E > ∼ 0.1 TeV. Key Words : cosmic ray acceleration – supernova remnants – hydrodynamics – methods:numerical

http://arxiv.org/pdf/astro-ph/0701027.pdf