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. Methodology Planetary Nebula candidates were found using Starry Night and the Williams Gallery of Planetary Nebula Spectra. Each candidate was chosen based on criteria NGC 7662 IC 1747 IC 289 M 1-4 M 2-2 NGC 7008 IC 5217 NGC 7354 NGC 650 NGC 40 NGC 1501 NGC 7009 NGC 7651 VY 1-1 • Analyzed using spectra from Williams Gallery of Planetary Nebula Spectra • Elements identified (emission lines), ionization potentials calculated Distances and size (in arc seconds) was determined using Starry Night as well as other research articles. Using the spectral data density was found by finding the peak height of λ 6716 and λ 6736 as well as the continuum height in the formula ((λ 6716-continuum height)/(λ 6736 – continuum height)). The value from that formula was then used in a graph, which then would match up with the density. Volumes were then determined using ((4/3)π*r3). Mass was then determined by (V*D). Maximum ionization potential was then compared with the masses. Graph of Intensity Ratio of λ6716 and λ6736 vs. Electron Density, used to calculate density Chart of Ionization Potentials for each element (measured in eV) Results (Above) Collected Spectra of 13 candidates showing emission lines. Graphs represent wavelength vs. flux. Range from 3600-10000 angstroms. Graph 1: Graph of each PN’s mass (in kg) and highest ionization potential value (measured in eV), line represents trend- direct correlation between mass and highest ionization potential

3. Results • Direct Correlation found between mass and highest ionization potential value (graph) • Chemical elements identified, generally lighter • heaviest overall- Ar • Discussion • Goals: identify elements, calculate ionization potentials/mass, find relationship • supports findings of Harrington (1969), Szyszka et. al (2009) • Correlation: more massive PN, greater value of highest ionization potential • More energy required- greater mass • Chemicals returned to interstellar medium lighter • heaviest element: Argon lightest element: Hydrogen • PNe early stages of life, only ionizing outer shells (seen in Figure 1) • Limitations • Originally planned for self-viewing and astrophotography • availablility of instruments • Conclusion • Mass and highest ionization potentials have correlation: greater mass related to larger ionization potential values • Chemicals returned to interstellar medium identified • PNe relatively early in life cycles • ionizing lighter ions, have not begun to ionize heavier materials near central star • Predict stellar evolution • Future Studies • Goncalvez et. al (2009)- relation between ionization and temperature • Relate ionization potentials to surface temperature and compare to mass 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, pg. 171. 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.” Astrophysical Journal. 9 June 2008. Santa Barbara Instrument Group. “DSS-7: Deep Space Spectrograph.” 20 March 2006. <http://www.sbig.com/sbwhtmls/online.htm> Szyszka C. et al. “Detection of the Central Star of the Planetary Nebula NGC 6302.” Astrophysical Journal. 21 October 2009. 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>/ Webster, Louise B. “The Masses and Galactic Distribution of Southern Planetary Nebulae.” Royal Astronomical Society. 11 April 1968.