Aging Star Clusters

Nick DiPreta

Globular Clusters• Similar age • 50 to 300 light years across• Hundreds to 200 million stars• Formed when the universe was young

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 http://apod.nasa.gov/apod/image/0711/pleiades_fs_big.jpg

Mass Segregation

• Larger Stars move towards center• Smaller stars move towards outer edges

Minimum Spanning Tree

• Prim algorithm

• Can be automated in excel

5

4

3

A B

C

Using The Minimum Spanning Tree to Trace Mass Segregation

• quantified mass segregation

Richard J. Allison 2009

Metallicity

• Heavier metals are created over time

• Shows amount of fusion that has occurred

• Shows age

Stellar Rotation

• proposed indirect measure of stellar age

• slows down as the star ages

• Can be measured using light curves- measurements of periodicity in photometric luminosity

Stellar Ages From Stellar RotationMeiborn

2008

blue red

• Mass segregation patterns found of single stars in Pleiades

Raboud and Milliad(2000)

Purpose

• To determine if stellar mass segregation occurs over time, and if so why. Also, to see if there is a relationship between age and mass segregation.

• To explore and determine the relationship between radial velocity and age.

Methodology Candidates Images obtained using CCD imager

Images processed and sharpened using photoshop

MST calculated using Prim algorithm

Mass Segregation Formula by Richard J Allison

Metallicity taken from surveys using National Virtual

Observatory

Rotational velocity taken photometrically in 3hrs/ hr for the full period of rotation of specific stars within a cluster n=40 (duration to be determined)

APT used to determine luminosity

Change in luminosity plotted to form light curve and determine rate of rotation

Compared to

Images obtained using CCD imager

Images processed and sharpened using photoshop

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

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

• Meibom, Søren. "Stellar Ages from Stellar Rotation." Proceedings of the International Astronomical Union 4.S258 (2008): 357.