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Star Clusters
Willy Wassmer
Knowledge Base
• Stars have similar age• Distances to Stellar
Objects can be found from Parallax view
Parallax Viewhttp://www.astro.umd.edu/resources/introastro/images/parallax.gif
Distance Modulus
• D=m-M• m represents apparent magnitude• M represents absolute magnitude
• Example: D=16-975+1+1
100*2.5*2.562510 parsecs *√62510 parsecs *25250 parsecs
Metallicity
• Fe/H
• Shows amount of fusion that has occurred
• Shows age
Mass Segregation
• Larger Stars move towards center• Smaller stars move towards outer edges • KE mass*speed2
Minimum Spanning Tree
• Prim algorithm
• Can be automated in excel
5
4
3
A B
C
Knowledge Base Cont.Globular Clusters
• Similar age • 50 to 300 light years across• Hundreds to 200 million stars• Formed when the universe was very young• Hercules Cluster
Hercules Cluster http://www.rc-astro.com/php/phpthumb/cache/phpThumb_cache_rc-astro.com_srce4d4565e800c0a1c8e17c177a7713b4e_par0ddf367c5f01d9ba090bf356b6761f52_dat1208719109.jpeg
Knowledge Base Cont.Open Clusters
• Stars have relatively Same age• Similar Chemical Composition• Composed of Younger Stars which are bright and
can be easily observed • Pleiades, Beehive, Perseus (double cluster), M6
cluster, Hyads
Pleiades http://apod.nasa.gov/apod/image/0711/pleiades_fs_bi
g.jpg
Using The Minimum Spanning Tree to Trace Mass Segregation
• quantified mass segregation
Richard J. Allison 2009
Ages of Globular Clusters Derived From BVRI CCD Photometry
• By using different wavelengths a different method of determining cluster age is presented
William Liller
• Mass segregation patterns
Observations and Theory of Star Cluster Formation
Bruce G. Elmegreen
Purpose
• To search for a correlation between metallicity and Mass segregation ratio.
Candidates
M39
M29
M103
M52
NGC 457
NGC 663
NGC 7790
NGC 7788
NGC 7209
NGC 7243
Pleiades- M45
Beehive Cluster- M44
Perseus Double Cluster-NGC 869 884
The Butterfly Cluster or M6
M34
M35
M47
M46
Jewel Box Cluster- NGC 4755
Ptolemy Cluster- M7
Methodology Candidates
Candidate Selection based on viewing time and altitude
Images obtained using CCD imager
Images processed and sharpened using MaxIm DL
MST calculated using Prim algorithm
Mass Segregation Formula by Richard J Allison
Search for correlation between Metallicity and Mass Segregation
Metallicity taken from surveys using National Virtual Observatory
Distance Calculated using distance modulus
Do-Ability
• Materials are readily available – Computer– CCD imager– Telescope– National Virtual Observatory
Budget
Equipment Cost
CCD Imager
MaxIm DL
$1895
$665 http://www.cyanogen.com/maximdl_buy.php Http://www.sbig.com/sbwhtmls/online.htm
Site/Supplier
Bibliography• The Columbia Encyclopedia, Sixth Edition Copyright ©2004, Columbia University Press. Licensed from Lernout &
Hauspie Speech Products N.V. All Rights Reserved. http://www.questia.com/library/encyclopedia/star_cluster.jsp • Eugenio Carretta “Abundances in Red Giant Stars of NGC 2808 and Correlations between Chemical Anomalies
and Global Parameters in Globular Clusters.” Osservatorio Astronomico di Bologna. The Astronomical Journal, 2006 March.http://adsabs.harvard.edu/abs/2006AJ....131.1766C
• Lee, H.; Kim, S.-L.; Kim, H.-J. ; Jeon, Y.-B.; Park, H,-S. “New Variable Stars in the Open Cluster M103.” Konkoly Observatory, Budapest, 26 October 2005, Dept. of Earth Science Education, Korea National University of Education, Korea Astronomy and Space Science Institute. http://adsabs.harvard.edu/abs/2005IBVS.5656....1L
• Gonzalo Alcaino and William Liller “Ages of Globular Clusters Derived from BVRI CCD photometry.” Instituto Isaac Newton, Ministerio de Educación de Chile, Santiago, Chile. Societá Astronomica Italiana, Vol 57 No. 3. http://adsabs.harvard.edu/abs/1986MmSAI..57..321A
• Prof. Fabrizio Mazzucconi, Enrico Albisetti and Bernardo Mannucci. “Atlas of The Skies: Journeying between the stars and planets in the discovery of the universe.”TAJ Books 2003
• Mike Lynch. “The Essential guide to Our Night Sky: New York Starwatch.” Voyageur Press 2005 p.46 and 47• Elmegreen, Bruce G., Yuri Efremov, Ralph E. Pudritz, and Hans Zinnercker. “Observations and Theory of Star
Cluster Formation.” http://www.uapress.arizona.edu/onlinebks/ppiv/chap07.pdf• Chandra X-ray Observatory (2008, April 29). Oldest Known Celestial Objects are Surprisingly Immature. Science
Daily. Retrieved April 28, 2009, from http://www.sciencedaily.com/releases/2008/04/080428140351.htm • ESA Hubble Information Centre (2008, August 6). Thousands of Globular Clusters Identified in Virgo Cluster of
Galaxies. Science Daily. Retrieved April 28, 2009, from http://www.sciencedaily.com/releases/2008/08/080805234054.htm