+

Criteria for CandidatesAltitude > 40°; Apparent Magnitude > 14;

Available Distance and Angular Radius; Available Spectra

IntroductionPlanetary nebulae are crucial in

returning heavier metals into the interstellar medium, influencing later

star and galaxy formation (Aller & Keyes, 87).

Project Goals-Identify emission lines

-Identify ionization potentials-Determine Density, Volume and Mass

Purpose To find a correlation between mass and ionization potentials as well as

to see if mass affects elements expelled into interstellar medium

Pictures of Candidates and Spectra from Williams (from top) NGC 7662; IC 1747; IC 289; M1-4; M2-2; NGC 7008; NGC

7534

Chart is a template that was used to determine spectral lines.

Probable chemical composition for planetary nebula.

Knowledge Base

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 starArnold, Jacob (2008)

MethodologyMethodology

Planetary Nebula candidates were found using Starry Night and the Williams Gallery of Planetary Nebula Spectra. Each candidate was

chosen based on criteria

Planetary Nebula candidates were found using Starry Night and the Williams Gallery of Planetary Nebula Spectra. Each candidate was

chosen based on criteria

NGC 7009NGC 7009

NGC

1501

NGC

1501

NGC 40

NGC 40

NGC 650NGC 650

NGC 7354NGC 7354

IC 5217

IC 5217

NGC 7008NGC 7008

M 2-2M 2-2M 1-4M 1-4IC 289IC

289IC

1747IC

1747NGC

7662

NGC

7662

NGC

7651

NGC

7651

VY 1-1

VY 1-1

Analyzed using spectra from Williams Gallery of Planetary Nebula Spectra

Elements identified (emission lines), ionization potentials calculated

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.

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).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. Maximum ionization potential was then compared with the masses.

Chart of Ionization Potentials for each element (measured in eV)Chart of Ionization Potentials for each element (measured in eV)

Graph of Intensity Ratio of λ6716 and λ6736 vs. Electron Density, used to

calculate density

Graph of Intensity Ratio of λ6716 and λ6736 vs. Electron Density, used to

calculate density

ResultsResults

0

5E+040

1E+041

1.5E+041

2E+041

2.5E+041

3E+041

3.5E+041

4E+041

4.5E+0410

10

20

30

40

50

60

70

Mass vs. Highest Ionization Potential

Mass (kg)

Hig

hest

Ioni

zatio

n Po

tenti

al (e

V)

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

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

(Above) Collected Spectra of 13 candidates showing emission lines.

Graphs represent wavelength vs. flux. Range from 3600-10000 angstroms.

(Above) Collected Spectra of 13 candidates showing emission lines.

Graphs represent wavelength vs. flux. Range from 3600-10000 angstroms.

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)

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

Limitations• Originally planned for self-viewing and astrophotography

• availablility of instruments

BibliographyAller & 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.”

AstrophysicalJournal. 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.