Criteria for Candidates

1. Introduction Planetary nebulae are crucial in returning heavier metals into the interstellar medium, influencing later star and galaxy formation (Aller & Keyes, 87). Criteria for Candidates Altitude > 40°; Apparent Magnitude > 14; Available Distance and Angular Radius; Available Spectra + Knowledge Base Probable chemical composition for planetary nebula. Chart is a template that was used to determine spectral lines. Pictures of Candidates and Spectra from Williams (from top) NGC 7662; IC 1747; IC 289; M1-4; M2-2; NGC 7008; NGC 7534 • Literature Review • -C. Szyka, JR Walsh et al determined the highest ionization potential of planetary nebula NGC 6302 by use of spectral analysis. They also calculated temperature. • K. Hermann et al determined the mass of several planetary nebulae and found distance using the luminosity function. • B Webster studied emissions of magellanic clouds as determined approximated distances. Figure 1 Stratification of ions: higher near core, lower farther from star Arnold, Jacob (2008) Purpose To find a correlation between mass and ionization potentials as well as to see if mass affects elements expelled into interstellar medium Project Goals -Identify emission lines -Identify ionization potentials -Determine Density, Volume and Mass

2. Results • Spectra reveal lighter chemical elements • Most massive overall- Ar • Significant direct correlation found between mass and highest ionization potential value, r=0.944 and p=0.01 (Graph 1) • Age (youngest to oldest) vs. average density: significant direct inverse relationship, younger nebulae are more dense than older, r=-0.926 and p=0.037 (Graph 2) • Discussion • Goals: identify element, calculate ionization potentials/mass, find correlation, relate to age and evolution • supports findings of Harrington (1969), Szyszka et. al (2009) • Direct correlation: more massive PN, greater value of highest ionization potential • Chemicals returned to interstellar medium lighter • PNe and central stars same composition • Future star formation- same present elements • Relative ages determined: heavier elements found in older PNe due to nuclear fusion over time • Grouped and compared to average density, inverse relationship found- older nebulae have lower densities due to less massive chemicals present and ionized • Limitations • Possible discrepancies in identification of emission lines • Conclusion • Mass and highest ionization potentials have correlation: greater mass related to larger ionization potential values • Less massive chemicals returned to interstellar medium and compose central stars and PNe • PNe relatively old in age • only light elements present, nuclear fusion did not create heavier elements yet • older PNe, less dense • Predict stellar evolution • Future Studies • Harrington (1969)- temperature and luminosities calculated from ionization potentials, help place nebulae along H-R diagram • Relation to mass, density, age Bibliography Aller & Keyes, et al. “A Spectroscopic Survey of 51 Planetary Nebulae.” 19871. Arnold, Jacob. “Planetary Nebulae. AY 230, Fall 2008. Canright, Shelley. “Stellar Evolution - The Birth, Life, and Death of a Star.” NASA. 10 April 2009. <http://www.nasa.gov/ audience/forstudents/912/features/stellar_evol_feat_912.html> Ciardullo, Robin. “The Planetary Nebula Luminosity Function.” Astrophysical Journal. 14 July 2004. Covington, Michael A. “Processing DSLR Raw Images with MaxDSLR and MaxIm DL.” 25 December 2006. http://www.covingtoninnovations.com/dslr/MaxDSLR/index.html#top Guerrero, Martin A. “Physical Structure of Planetary Nebulae. II. NGC 7662.” The Astronomical Journal, American Astronomical Society. October 2004. Flower, D.R. “The Ionization Structure of Planetary Nebulae-VII:The Heavy Elements.” Royal Astronomical Society, Vol. 146, pg171. 24 July 1969. Herrmann, Kimberly A. “Planetary Nebulae in Face-On Spiral Galaxies. II. Planetary Nebula Spectroscopy.” Astrophysical Journal. 4 August 2009. Jacoby, George et al. “A Library of Stellar Spectra.” Astrophysical Journal. October 1984. Kelusa, Craig. “What is Spectroscopy?” University of Arizona. 14 Feb 1997. <http://loke.as.arizona.edu/~ckulesa/camp/spectroscopy_intro.html> Kwitter, Karen B. “Gallery of Planetary Nebulae Spectra.” Williams College.<http://oit.williams.edu/nebulae/Exercise1.html> 2006. Lee, Kevin. “Spectral Classification of Stars.” 2005. <http://astro.unl.edu/naap/hr/hr_background1.html> Lestition, Kathy. “Stellar Evolution.” Chandra X-Ray Observatory. NASA. 24 September 2008. <http://chandra.harvard.edu/edu/formal/stellar_ev/> National Optical Astronomy Observatory. “Spectral Analysis for the RV Tau Star R Sct.”RBSE. 2008. Ransom, R. R. et al. “Probing the Magnetized Interstellar Medium Surrounding the Planetary Nebula SH 2-216.”AstrophysicalJournal. 9 June 2008. Sabbadin, F. “Planetary Nebulae at Known Distance.” Astronomy and Astrophysics Supplement Series Vol. 64, No. 3. June 1986. Sandin, Christopher et. al. “Spatially Resolved Spectroscopy of Planetary Nebulae and their Halos.” Astronomy & Astrophysics Institute Potsdam, Germany. 4 July 2008. Santa Barbara Instrument Group. “DSS-7: Deep Space Spectrograph.” 20 March 2006. <http://www.sbig.com/sbwhtmls/online.htm> Seeds, Michael A. Foundations of Astronomy. Brooks/Cole. 2005. Sloan Digital Sky Survey. “The Hertzsprung-Russell Diagram.” 2007.<http://cas.sdss.org/dr7/en/proj/advanced/hr/> Stanghellini, Letizie. “The Magellanic Cloud Calibration of the Galactic Planetary Nebula Scale.” Astrophysical Journal. 7 July 2008. Szyszka C. et al. “Detection of the Central Star of the Planetary Nebula NGC 6302.” Astrophysical Journal. 21 October 2009. Webster, Louise B. “The Masses and Galactic Distribution of Southern Planetary Nebulae.” Royal Astronomical Society. 11 April 1968.