Click here for my listing in the ADS database.

Publications
Steffl, A. J., P. A. Delamere, and F. Bagenal (2008) Cassini UVIS observations of the Io plasma torus IV. Modeling temporal and azimuthal variability, Icarus, 194, 153-165.

Retherford, K.D., J. R. Spencer, S. A. Stern, J. Saur, D. F. Strobel, A. J. Steffl, G. R. Gladstone, H. A. Weaver, A. F. Cheng, J. Wm. Parker, D. C. Slater, M. H. Versteeg, M. W. Davis, F. Bagenal, H. B. Throop, R. M. C. Lopes, D. C. Reuter, A. Lunsford, S. J. Conard, L. A. Young, and J. M. Moore (2007) Io’s Atmospheric Response to Eclipse: UV Aurorae Observations, Science, 318, 237-240.

Gladstone, G.R., S. A. Stern, D. C. Slater, M. Versteeg, M. W. Davis, K. D. Retherford, L. A. Young, A. J. Steffl, H. Throop, J. Wm. Parker, H. A. Weaver, A. F. Cheng, G. S. Orton, J. T. Clarke, J. D. Nichols (2007) Jupiter’s Nightside Airglow and Aurora, Science, 318, 229-231.

Steffl, A.J., Stern, S.A. (2007) First Constraints on Rings in the Pluto System, Astron. J., 133, 1485-1489.

Feldman, P.D.,  Stern, S.A., Steffl, A.J., Parker, J.W., Slater, D.C., A'Hearn, M.F., Bertaux, J.-L.,  Festou, M.C., (2007) Ultraviolet Spectroscopy of Comet 9P/Tempel 1 with Alice/Rosetta during the Deep Impact Encounter, Icarus, 187, 104-108.

Steffl, A.J.,  Mutchler, M.J., Weaver, H.A., Stern, S.A., Durda, D.D., Terrell, D., Merline, W.J., Young, L.A., Young, E.F., Buie, M.W., Spencer, J.R. (2006) New Constraints on Additional Satellites of the Pluto System. Astron. J., 132, 614-619.

S.A. Stern, H.A. Weaver, M.J. Mutchler, A.J. Steffl, M.W. Buie, W.J. Merline, J.R. Spencer, E.F. Young, L.A. Young, (2006) S/2005 P 1 and S/2005 P 2, IAU Circ., 8686.

Stern, S. A., H.A. Weaver, A.J. Steffl, M.J. Mutchler, W.J. Merline, M.W. Buie, E.F. Young, L.A. Young, J.R. Spencer (2006) A giant impact origin for Pluto's small moons and satellite multiplicity in the Kuiper belt, Nature, 439, 946-948.

Weaver, H.A., S.A. Stern, M.J. Mutchler, A.J. Steffl, M.W. Buie, W.J. Merline, J.R. Spencer, E.F. Young, L.A. Young (2006) Discovery of two new satellites of Pluto, Nature,  439, 943-945.

Mutchler, M.J., A.J. Steffl, H.A. Weaver, S.A. Stern, M.W. Buie, W.J. Merline, J.R. Spencer, E.F. Young, L.A. Young, (2006) S/2005 P 1 and S/2005 P 2, IAU Circ., 8676.

Steffl, A.J., Delamere, P.A., Bagenal, F. (2006) Cassini UVIS observations of the Io plasma torus. III. Observations of Temporal and Azimuthal Variability, Icarus, 180, 124-140.

Pryor, W.R., Stewart, A.I.F., Esposito, L.W., McClintock, W.E., Colwell, J.E., Jouchoux, A.J., Steffl, A.J, Shemansky, D.E., Ajello, J.M., West, R.A., Hansen, C.J., Tsurutani, B.T., Kurth, W.S., Hospodarsky, G.B., Gurnett, D.A., Hansen, K.C., Waite, J.H. Jr., Crary, F.J., Young, D.T. Krupp, N. Clarke, J.T., Grodent, D., Dougherty, M.K. (2005) Cassini UVIS observations of Jupiter's auroral variability. Icarus, 178, 312-326.

Delamere, P.A., Steffl, A.J., Bagenal, F. (2005) Radial variations in the io plasma torus during the Cassini era, J. Geophys. Res., 110, A12223.

Weaver, H. A., S.A. Stern, M.J. Mutchler, A.J. Steffl, M.W. Buie, W.J. Merline, J.R. Spencer, E.F. Young, L.A. Young, (2005) S/2005 P 1 and S/2005 P 2, IAU Circ., 8625.

Steffl, A.J., (2005) The Io plasma torus during the Cassini encounter with Jupiter: temporal, radial, and azimuthal variations,  Ph.D. Thesis, University of Colorado.

Steffl, A.J., F. Bagenal, A.I.F. Stewart, (2004) Cassini UVIS observations of the Io plasma torus. II. Radial variations. Icarus, 172, 91-103.

Steffl, A.J., A.I.F. Stewart, F. Bagenal, (2004) Cassini UVIS observations of the Io plasma torus. I. Initial Results. Icarus, 172, 78-90.

Delamere, P.A., A.J. Steffl, F. Bagenal, (2004) Modeling temporal variability of plasma conditions in the Io torus during the Cassini era, J. Geophys. Res., 109 A10216.


Preprints
Stern, S. A., M. J. Mutchler, H. A. Weaver, and A. J. Steffl (2006) The positions, colors, and photometric variability of Pluto's small satellites from HST observations 2005-2006, Astron. J., Submitted.


Posters and Presentations
Greathouse, T. K., Vervack, R. J., Gladstone, G. R., Stern, S. A., Slater, D. C., Versteeg, M., Davis, M. W., Retherford, K. D., Young, L. A., Steffl, A. J., Throop, H., and Parker, J. W. (2007) New Horizons Alice UV Observations of a Stellar Occultation by Jupiter's Atmosphere, AGU Fall Meeting 2007, abstract #P53C-05

Retherford, K. D., Spencer, J. R., Gladstone, G. R.; Stern, S. A.; Saur, J., Strobel, D. F., Slater, D. C., Steffl, A. J., Parker, J. W., Versteeg, M., Davis, M. W., Throop, H., and Young, L. A. (2007) Icy Galilean Satellite UV Observations by New Horizons and HST, AGU Fall Meeting 2007, abstract# P53C-06.

Feldman, Paul D.; Steffl, A. J.; Parker, J. W.; Slater, D. C.; Versteeg, M.; Stern, S. A.; A'Hearn, M. F.; Bertaux, J. L.; Weaver, H. A. (2007) The Far-Ultraviolet Spectrum of Mars Observed during the Rosetta Swingby of Mars in February 2007, 39^th DPS Meeting, Orlando, FL.

Gladstone, Randy; Stern, A.; Slater, D.; Versteeg, M.; Davis, M.; Retherford, K.; Young, L.; Steffl, A.; Throop, H.; Parker, J.; Weaver, H. A.; Cheng, A.; Orton, G.; Clarke, J.; Nichols, J.; New Horizons Science Team (2007) Jupiter's Airglow and Aurora as seen from New Horizons, 39^th DPS meeting, Orlando, FL.

Retherford, Kurt D.; Spencer, J. R.; Stern, S. A.; Cheng, A. F.; Saur, J.; Weaver, H. A.; Strobel, D. F.; Reuter, D. C.; Steffl, A. J.; Gladstone, G. R.; Parker, J. W.; Slater, D. C.; Lunsford, A.; Lopes, R. M.; Bagenal, F.; Throop, H. B.; Young, L. A.; Moore, J. M.; New Horizons Science Team (2007) Io Eclipse Observations During the New Horizons Jupiter Flyby, 39^th DPS meeting, Orlando, FL.

Stern, S. A.; Durda, D.; Steffl, A.; Hassler, D.; Cunningham, N. (2007) New Constraints from STEREO on the Population of Vulcanoids Interior to Mercury, 39^th DPS meeting, Orlando, FL.

Steffl, Andrew J.; A'Hearn, M. F.; Bertaux, J. L.; Feldman, P. D.; Gladstone, G. R.; Parker, J. W.; Retherford, K. D.; Slater, D. C.; Stern, S. A.; Versteeg, M.; Weaver, H. A. (2007) UV Observations of the Io Plasma Torus from New Horizons and Rosetta, 39^th DPS meeting, Orlando, FL.

Steffl, A.J., P.D. Feldman, G.R. Gladstone, J. Wm. Parker, K.D. Retherford, and S.A. Stern (2007) UV Observations of the Io Plasma Torus from New Horizons and Rosetta, Magnetospheres of the Outer Planets Conference, San Antonio, Texas.

Steffl, A.J., Delamere, P.A., and Bagenal, F., (2007) The Tail Wagging the Dog: Hot Electrons as the Driver of Azimuthal Variations in the Io Plasma Torus, Magnetospheres of the Outer Planets Conference, San Antonio, Texas.

Stern, S. A., Mutchler, M. J., Weaver, H. A., and Steffl, A. J. (2007) The Positions, Colors, and Photometric Variability of Pluto's Small Satellites from HST Observations: 2005-2006, 38th Lunar and Planetary Science Conference, League City, Texas. 1338, 1722.

Steffl, A. J., Gladstone, R., Retherford, K. D., and Stern, A. (2006) Cassini UVIS Observations of the Saturnian Magnetosphere, AGU Fall Meeting 2006, abstract# SM23A-0291.

Stern, S. A., Steffl, A. J., Bertaux, J., Leblanc, F (2006) Mars Express Spicam Observations Of The UV Nightglow And Auroral Emissions Of Mars, 38^th DPS Meeting, Pasadena, CA.

Steffl, A.J., Stern, S.A., (2006) First Observational Constraints on Rings in the Pluto System, 38^th DPS Meeting, Pasadena, CA.

Mutchler, M.J., Stern, S.A., Weaver, H.A., Steffl, A.J. (2006) The B-V Colors and Photometric Variability of Nix and Hydra, Pluto's Two Small Satellites, 38^th DPS Meeting, Pasadena, CA.

Stern, S. A., H.A. Weaver, A.J. Steffl, M.J. Mutchler, W.J. Merline, M.W. Buie, E.F. Young, L.A. Young, J.R. Spencer (2006) The Origin of the Quadruple System at Pluto
37^th Annual Lunar and Planetary Science Conference, League City, Texas, abstract no.1241.

Steffl, A.J., Delamere, P.A., Bagenal, F., (2005) Modeling the Temporal and Azimuthal Variability of the Io Plasma Torus Observed by Cassini UVIS, AGU Fall Meeting, San Francisco, CA.

Schneider, N.M., Robbins, S.J., Delamere, P.A., Steffl, A.J. (2005) Ion temperature control of the Io plasma torus, 37^th DPS Meeting, Cambridge, England.

Steffl, A.J., Delamere, P.A., Bagenal, F., (2005) Temporal and azimuthal variability in the Io plasma torus, Magnetospheres of the Outer Planets Conference, Leicester, England.

Steffl, A.J., Delamere, P.A., Bagenal, F., (2005) Modeling the temporal and azimuthal variability in the Io plasma torus observed by Cassini UVIS, Magnetospheres of the Outer Planets Conference, Leicester, England.

Delamere, P.A., Steffl, A.J., Bagenal, F., (2005) Radial variations of the Io plasma torus, Magnetospheres of the Outer Planets Conference, Leicester, England.

Steffl, A.J., Delamere, P.A., Bagenal, F., (2004) Azimuthal variability and subcorotation in the Io plasma torus as observed by Cassini UVIS, 36^th DPS Meeting, Louisville, Kentucky.

Bagenal, F., Delamere, P.A., Steffl, A.J., (2004) Modeling variability of the Io plasma torus, 36^th DPS Meeting, Louisville, Kentucky.

Steffl, A.J., Bagenal, F., Delamere, P.A., (2004) Longitudinal and temporal variations in the Io plasma torus during the Cassini Jupiter flyby, Joint AGU/CGU Meeting, Montreal, Canada.

Bagenal, F., Delamere, P.A., Steffl, A.J., Horanyi, M. (2004) Time variability of plasma production in the Io torus, Joint AGU/CGU Meeting, Montreal, Canada.

Steffl, A.J., Bagenal, F., Stewart, A.I.F., Delamere, P.A., (2003) Variability in the Io torus as observed by Cassini UVIS, 35^th DPS Meeting, Monterrey, California.

Bagenal, F., Delamere, P.A., Steffl, A.J., (2002) Temporal variability of Io plasma torus sources and sinks, AGU Fall Meeting, San Francisco, California.

Steffl, A.J., Stewart, A.I.F., Bagenal, F., Delamere, P.A., (2002) The Io plasma torus with Cassini UVIS, 34^th DPS Meeting, Birmingham, Alabama.

Steffl, A.J., Stewart, A.I.F., Bagenal, F., (2002) The Io plasma Torus with Cassini UVIS, Magnetospheres of the Outer Planets Conference, Laurel, Maryland.

Bagenal, F., Delamere, P.A., Steffl, A.J. (2002) Io plasma torus chemistry and energetics. AGU Spring Meeting, Washington, D.C.

Bagenal, F., Delamere, P.A., Steffl, A.J. (2002) Io plasma torus chemistry and energetics. 34^th COSPAR Scientific Assembly, The Second World Space Congress, Houston, Texas.

Steffl, A.J., Stewart, A.I.F., Bagenal, F. Schneider, N.M. (2001) Radial structure of the Io plasma torus from Cassini UVIS, 33rd DPS Meeting, New Orleans, Louisiana.

Steffl, A.J., Stewart, A.I.F., Bagenal, F. Schneider, N.M. (2001) Radial structure of the Io plasma torus from Cassini UVIS, Jupiter: Planet, Satellites and Magnetosphere Conference, Boulder, Colorado.

Woodward, R.C., Jr., Oliversen, R.J., Scherb, F., Steffl, A., Hilton, G.M., Doane, N.E. (1999) Synoptic broadband imaging of the Io plasma torus in S II: First results, 194^th AAS Meeting, Chicago, Illinois.

Steffl, A.J., Scherb, F., Harris, W.M. (1998) Adaptive optics imaging of Io Na D-line emission from the Mt. Wilson 100" telescope, 30th DPS Meeting, Madison, Wisconsin.

Oliversen, R.J., Scherb, F., Roesler, F.L., Woodward, R.C., Steffl, A.J., Corliss, J., Doane, N.E., Freed, M. (1997) High resolution spectroscopy of Io [O I[ 6300 Angstroms emission, 191^st AAS Meeting, Washington, D.C.