Ph.D. Planetary Sciences, University of Arizona,
1995
Ph.D. minor:
Physics
Dissertation
title: Observations of Small-Amplitude Oscillations
in the Radial Velocity of Arcturus
Dissertation
director: Dr. Robert S. McMillan
B.S. Physics and Astronomy, University of
Wisconsin - Madison, 1978
Mathematics,
University of Wisconsin - Madison, 1978
Dr. Merline is Principal Investigator of programs, funded by NASA and
NSF, to perform a ground-based search for asteroidal satellites. The programs employ the relatively new
technology of adaptive optics to reduce the blurring caused by the Earth’s
atmosphere. This work is carried out
primarily at the Keck, CFHT, and Gemini telescopes atop Mauna Kea, Hawaii. Dr. Merline led this international team in
the first-ever discovery of an asteroidal satellite from the Earth
(ground-based or HST), that of 45 Eugenia in 1998. Subsequently, the team also discovered a small moon of 762
Pulcova, the first double asteroid to be imaged, 90 Antiope, the first Trojan
binary asteroid, 617 Patroclus, and co-discovered the first binary M-type
asteroid, 22 Kalliope.
He also has two programs
funded under NASA’s Applied Information Systems Program to develop
artificial-intelligence tools for crater detection and analysis, and also to
develop web-based science analysis tools. He is also managing the SwRI-side of
a project, with JPL, to produce an on‑board software technology‑demonstration,
using artificial intelligence, to automate, among other tasks, a search for
asteroidal satellites on future spacecraft missions. The method has been applied to NEAR images of Eros.
He was an
Associate Member of the Imaging & Near-Infrared Spectrometer Team of the
NEAR (Near-Earth Asteroid Rendezvous) spacecraft mission. He had the prime responsibility for the
search for satellites of asteroid Mathilde using NEAR images, and during the
1999 flyby and 2000 orbital tour of asteroid Eros.
Dr. Merline's
Ph.D. dissertation was entitled "Observations of Small‑Amplitude
Oscillations in the Radial Velocity of Arcturus". During this work, he helped design, build,
test, calibrate, and operate a spectrometer designed for extreme sensitivity to
small changes in the radial velocities of stars. This instrument was one of the first systems built to search for
planets around other stars by the radial-velocity method, the method that has
been used to find virtually all of the known extrasolar planets. The dissertation work led directly to the
discovery of what will likely be a new class of variable stars (K giants),
previously thought to be stable. His work has shown that the oscillations in
Arcturus are complex and analogous to solar acoustic oscillations. He also produced a computational/theoretical
study showing methods for optimizing the amount of information obtained in
radial velocity observations.
Astronomical interests include the detection of extra‑solar
planetary systems, velocity variations in the Sun and stars, the solar/stellar
connection, and optimization of radial velocity determination and of
photometric observations with CCDs.
He is an
associate of the imaging team of the Galileo spacecraft mission. He (with Clark Chapman) had the prime
responsibility for analysis of the Galileo imaging data of the Shoemaker‑Levy
9 collision with Jupiter, the only direct images of the actual impacts. He is currently involved with analysis of
the Galileo images of Jupiter's satellites Europa, Ganymede, and Callisto, to determine surface histories from the
crater record. He is Principal Investigator for a program to study
cratering on the Galilean satellites under NASA’s Jovian System Data Analysis
Program.
He has played a
major role in the analysis of Galileo imaging data of Gaspra, Ida, and
Dactyl. He assisted in the
determination of the orbit of the satellite of Ida, Dactyl, and in the
associated estimates of Ida's bulk density.
He had the prime responsibility for the search for additional satellites
of Ida and also performed a cursory search for satellites of Gaspra. He was heavily involved in the post‑discovery
search for Dactyl using HST images, in support of the orbit‑determination
effort on Galileo.
1998-present
Senior Research Scientist, Southwest
Research Institute, Boulder, CO
1997-1998
Research Scientist, Southwest Research Institute, Boulder, CO
1996-1997
Postdoctoral Researcher, Southwest
Research Institute, Boulder, CO
Asteroid 7607 Billmerline named in his honor
NASA
Certificate of Recognition, 1999, “Technically Significant Software: Satellite
Detector”
NASA Certificate of
Recognition, 1998, “Technically Significant Software: Onboard UV Spectral
Analyzer”
Merline,
W.J., Weidenschilling, S.J., Durda, D.D., Margot, J-L., Pravec, P., Storrs,
A.D. “Asteroids Do Have Satellites”, in Asteroids III, eds. W.F.
Bottke, A. Cellino, P. Paolicchi, & R.P. Binzel, Univ. of Arizona Press, in revision (2002).
Merline, W.J. “Asteroid Satellites” (Invited), BAAS
33, 5101 (2001).
Merline, W.J. “Asteroid Satellites” (Invited), Asteroids
2001, Sicily (2001).
Veverka,
J., Farquhar, B., Robinson, M., Thomas, P., Murchie, S., Harch, A., Antreasian,
P.G., Chesley, S.R., Miller, J.K., Owen, W.M., Williams, B.G., Yeomans, D.,
Dunham, D., Heyler, G., Holdridge, M., Nelson, R.L., Whittenburg, K.E., Ray,
J.C., Carcich, B., Cheng, A., Chapman, C., Bell, J.F., Bell, M., Bussey, B.,
Clark, B., Domingue, D., Gaffey, M.J., Hawkins, E., Izenberg, N. Joseph, J.,
Kirk, R., Lucey, P., Malin, M., McFadden, L., Merline, W.J., Peterson, C.,
Prockter, L., Warren, J., Wellnitz, D.
“The landing of the NEAR-Shoemaker spacecraft on asteroid 433 Eros”, Nature
413, 390 (2001).
Merline,
W.J., Close, L.M., Siegler, N., Potter, D., Chapman, C.R., Dumas, C., Menard,
F., Slater, D.C., Baker, A.C., Edmunds, M.G., Mathlin, G., Guyon, O., Roth, K.
“S/2001 (617) 1”, IAU Circular 7741 (2001).
Merline,
W.J., Chapman, C.R. “Implications of
Asteroidal Satellites”, Meteorit. Planet. Sci. 36 (Suppl.), A132
(2001).
Merline,
W.J., Menard, F., Close, L., Dumas, C., Chapman, C.R., Slater, D.C. “S/2001
(22) 1”, IAU Circular 7703 (2001).
Chapman,
C.R., Merline, W.J., Thomas, P.C., Joseph, J., Cheng, A.F., Izenberg, N.
“Impact History of Eros: Craters and Boulders”, Icarus, in press (2002).
Merline,
W.J., Close, L.M., Menard, F., Dumas, C., Chapman, C.R., Slater, D.C. “Search
for Asteroid Satellites”, BAAS 33, 5201 (2001).
Merline,
W.J., Tamblyn, P., Chapman, C.R., Colwell, W.B., Gor, V., Burl, M.C., Bierhaus,
E.B., Robinson, M.S. “An Autonomous Search for Moons during Approach of the
NEAR Spacecraft to Asteroid Eros”, Proc. 6th International
Symposium on Artificial Intelligence, Robotics, and Automation in Space, in
press (2002).
Parker,
J.W., Stern, S.A., Thomas, P.C., Festou, M.C., Merline, W.J., Young, E.F.,
Binzel, R.P., Lebofsky, L.A., “Analysis of the First Disk-Resolved Images of
Ceres from Ultraviolot Observations with the Hubble Space Telescope”, Astron.
J. 123, 549 (2002).
Veverka,
J., Thomas, P.C., Robinson, M., Murchie, S., Chapman, C., Bell, M., Harch, A.,
Merline, W.J., Bell, J.F., Bussey, B., Carcich, B., Cheng, A., Clark, B.,
Domingue, D., Dunham, D., Farquhar, R., Gaffey, M.J., Hawkins, E., Izenberg,
N., Joseph, J., Kirk, R.H., Li, H., Lucey, P., Malin, M., McFadden, L., Miller,
J.K., Owen, W.M., Peterson,
C., Prockter, L., Warren, J., Wellnitz, D., Williams, B.G., Yeomans, D.K.
“Imaging of Small-Scale Features on 433 Eros from NEAR: Evidence for a Complex
Regolith”, Science 292, 484 (2001).
Merline, W.J., Close, L.M., Shelton, J.C.,
Dumas, C., Menard, F., Chapman, C.R., Slater, D.C. “Satellites of Minor
Planets”, IAU Circular 7503 (2000).
Close, L.M., Merline, W.J., Dumas, C.,
Chapman, C.R., Roddier, F.J., Menard, F., Slater, D.C., Duvert, G., Shelton,
J.C., Morgan, T.H. “Search for asteroidal satellites using adaptive optics”, Proc.
SPIE 4007, 796 (2000).
Close, L.M., Merline, W.J., Tholen,
D.J., Owen, T.C., Roddier, F.J., Dumas, C. “Adaptive optics imaging of
Pluto-Charon and the discovery of a moon around the Asteroid 45 Eugenia: the
potential of adaptive optics in planetary astronomy”, Proc. SPIE 4007,
787 (2000).
Merline, W.J.,
Close, L.M., Dumas, C., Chapman, C.R., Roddier, F., Menard, F., Slater, D.C.,
Duvert, G., Shelton, C., Morgan, T. “Discovery of a moon orbiting the asteroid
45 Eugenia”, Nature 401, 565
(1999).
Merline, W.J.,
Close, L.M., Dumas, C., Chapman, C.R., Roddier, F., Menard, F., Colwell, W.,
Slater, D.C., Duvert, G., Shelton, C., Morgan, T. “Discovery of a Satellite of
(45) Eugenia”, abstract for invited talk,
Asteroids, Comets, Meteors ’99 (1999).
Merline, W.J.,
Close, L.M., Dumas, C., Chapman, C.R., Roddier, F., Menard, F., Slater, D.,
Duvert, G., Shelton, C. Morgan, T., Dunham, D.W. “S/1998(45)1”, IAU Circular
7129 (1999).
Merline, W.J.,
Chapman, C.R., Colwell, W.B., Veverka, J., Harch, A., Bell, M., Bell, J.F. III,
Thomas, P., Clark, B.E., Martin, P., Murchie, S., Cheng, A., Domingue, D.,
Izenberg, N., Robinson, M., McFadden,
L., Wellnitz, D., Malin, M., Owen, W., Miller, J. “Search for Satellites Around
Asteroid 433 Eros from NEAR Flyby Imaging”, Proc. Lunar & Planetary Sci.
Conf. 30, 2055 (1999).
Merline, W.J.,
Close, L.M., Dumas, C., Chapman, C.R., Roddier, F., Menard, F., Colwell, W.,
Slater, D.C., Duvert, G., Shelton, C., Morgan, T. “Discovery of Asteroidal
Satellite S/1998 (45) 1”, Bull. AAS 31, 2006 (1999).
Veverka, J.,
Thomas, P., Harch, A., Clark, B., Bell, J.F., Carcich, B., Joseph, J., Murchie,
S., Izenberg, N., Chapman, C., Merline, W., Malin, M., McFadden, L., Robinson,
M., “NEAR Encounter with Asteroid 253
Mathilde: Overview”, Icarus 140, 3 (1999).
Murchie, S.,
Robinson, M., Hawkins, S.E., Harch, A., Helfenstein, P., Thomas, P., Peacock,
K., Owen, W., Heyler, G., Murphy, P., Darlington, E.H., Keeney, A., Gold, R.,
Clark, B., Izenberg, N., Bell, J.F., Merline, W., Veverka, J. “Inflight
Calibration of the NEAR Multispectral Imager”, Icarus 140, 66
(1999).
Chapman, C.R.,
Merline, W.J., Thomas, P. “Cratering on Mathilde”, Icarus 140, 28
(1999).
Thomas, P.C.,
Veverka, J., Bell, J.F. Clark, B.E., Carcich, B., Joseph, J., Robinson, M.
McFadden, L.A., Malin, M.C., Chapman, C.R., Merline, W., Murchie, S. “Mathilde:
Size, Shape, and Geology”, Icarus 140, 17 (1999).
Merline, W.J.,
Chapman, C.R., Robinson, M., Murchie, S., Veverka, J., Harch, A., Bell, J. III,
Thomas, P., McFadden, L., Malin, M., Clark, B.E., Izenberg, N., Joseph, J.,
Carcich, B., Murphy, P., Heyler, G., Cheng, A. “Search for Satellites of 253
Mathilde from Near-Earth Asteroid Rendezvous Flyby Data”, Meteoritics &
Planetary Science 33, 105 (1998).
Clark, B.E., Veverka, J.,
Thomas, P.C., Joseph, J., Carcich, B.T., Helfenstein, P., Murchie, S.,
Domingue, D., Robinson, M.S., Owen, W., Merline, W.J. “NEAR Lightcurves of
Eros: Evidence for Albedo Variations at Lons 240-300”, BAAS 31
(1999).
Merline, W.J.,
Chapman, C.R., Robinson, M., Veverka, J., Harch, A., Bell, J. III, Thomas, P.,
Joseph, J., Carcich, B., Murchie, S., Cheng, A., Izenberg, N., McFadden, L,
Malin, M., Clark, B.E. “NEAR’s Encounter with 253 Mathilde: Search for
Satellites”, Proc. Lunar & Planetary Sci. Conf. 29, 1954
(1998).
Klaasen, K.,
Belton, M., Breneman, H., McEwen, A., Davies, M., Sullivan, R., Chapman, C.
Neukum G., Heffernan, Harch, A., Kaufman, J., Merline, W., Gaddis, L.,
Cunningham, W., Helfenstein, P., and Colvin, T. “Inflight Performance Characteristics, Calibration, and
Utilization of the Galileo SSI Camera”, Optical
Engineering 36, 3001 (1998).
Veverka, J.,
Thomas, P., Harch, A., Clark, B., Bell, J.F. III, Carcich, B., Joseph, J.,
Chapman, C., Merline, W., Robinson, M., Malin, M., McFadden, L.A., Murchie, S.,
Hawkins, S.E. III, Farquhar, R., Izenberg, N., Cheng, A. “NEAR’s Flyby of 253
Mathilde: Images of a C Asteroid”, Science 278, 2109 (1997).
Belton, M.J.S.,
Mueller, B.E.A., D’Amario, L.A., Byrnes, D.V., Klaasen, K.P., Synnot, S.,
Breneman, H., Johnson, T.V., Thomas, P.C., Veverka, J., Harch, A.P., Davies,
M.E., Merline, W.J., Chapman, C.R., Davis, D., Denk, T., Neukum, G., Petit,
J-M., Greenberg, R., Storrs, A., Zellner, B. “The Discovery and Orbit of 1993 (243)1
Dactyl”, Icarus 120, 185 (1996).
Chapman, C.R.,
Ryan, E.V., Merline, W.J., Neukum, G., Wagner, R., Thomas, P.C., Veverka, J.,
Sullivan, R.J. “Cratering on Ida”, Icarus 120, 77 (1996).
Chapman, C.R.,
Veverka, J., Thomas, P.C., Klaasen, K., Belton, M.J.S., Harch, A., McEwen, A.,
Johnson, T.V., Helfenstein, P., Davies, M.E., Merline, W.J., Denk, T.
“Discovery and Physical Properties of Dactyl a Satellite of Asteroid 243 Ida”, Nature
374, 783 (1995).
Belton, M.,
Chapman, C., Thomas, P., Davies, M., Greenberg, R., Klaasen, K., Byrnes, D.,
D’Amario, L., Synnott, S., Merline, W., Petit, J-M., Storrs, A., Zellner, B.
“The bulk density of asteroid 243 Ida from Dactyl’s orbit”, Nature 374,
785 (1995).
Chapman,
C.R., Merline, W.J., Klaasen, K., Johnson, T.V., Heffernan, C., Belton, M.J.S.,
Ingersoll, A.P. “Preliminary results of Galileo direct imaging of SL9 impacts”,
Geophysical Research Letters 22, 1561 (1995).
Merline, W.J.
and Howell, S.B., "A Realistic Model for Point‑Sources Imaged on
Array Detectors: The Model and Initial
Results", Experimental Astronomy,
6, 163-210 (1995).
Bierhaus, E.B.,
Merline, W.J., Chapman, C.R., Burl, M.C. “Characteristics of Secondary Craters
Using Machine Vision”, Proc. 6th International Symposium on
Artificial Intelligence, Robotics, and Automation in Space, in press
(2002).
Burl, M.C.,
Stough, T., Colwell, W., Bierhaus, E.B., Merline, W.J., Chapman, C.R.
“Automated Detection of Craters and Other Geological Features”, Proc. 6th
International Symposium on Artificial Intelligence, Robotics, and Automation in
Space, in press (2002).
Merline, W.J.,
“Precise Velocity Observations of K-Giants: Evidence for Solar-like
Oscillations in Arcturus”, Proc. of IAU Colloquium 170, Vol. 185, Precise
Stellar Radial Velocities (J.B. Hearnshaw & C.D. Scarfe, eds.),
p. 187 (1999).