Star Clusters

Willy Wassmer

And

Nick DiPreta

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

Spectroscopy• Used to study properties of a star ex:

metalicity

• Spectroscope-makes graph of intensity

<http://www.sbig.com/dss7/dss7_25s.jpg>.

•http://loke.as.arizona.edu/~ckulesa/camp/spectroscopy_intro.html>. http://www.astro.washington.edu/users/premap/images/project_images/solar_spectrum.jpg

Metallicity

• Fe/H

• Shows amount of fusion that has occurred

• Shows age

Photometry

• Luminosity• CCD imager- longer exposures better images• filters• APT- image J

http://teleskop-service.se/produkter/eng/atikpics/start/mit-rgb-2.jpg>.http://teleskop-service.se/produkter/eng/atikpics/start/mit-rgb-2.jpg>.

Image Stacking• Spectrograph/CCD create image

• Stacking images increases quality

• Photoshop/MaxIm DL

http://teleskop-service.se/produkter/eng/atikpics/start/mit-rgb-2.jpg>.

Astroimaging/Preprocessing

• Darks

• Bias

• Flats

• Signal to noise ratio

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

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_big.jpg

HR Diagram• observation

and stellar evolution

• From observation other facts can be derived.

•<http://www.bramboroson.com/astro/images/hrdiagram.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

No evidence of mass Segregation in Massive Young Clusters

• Mass segregation methods (including MST) not 100% accurate

J. Acenso

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