Robert Paul

Robert Paul Kraft


Date of Birth
June 16, 1927
Date of Death
May 26, 2015

Bob Kraft was was born in Seattle and earned his bachelor’s and master’s degrees at the University of Washington. He taught mathematics and astronomy for two years at Whittier College and then entered the University of California, Berkeley, where he worked for Otto Struve and earned his Ph.D. in 1955 under George Herbig. After short stays at Mt. Wilson ObservatoryIndiana University, and Yerkes Observatory, he served on the staff of the Mt. Wilson & Palomar Observatories for seven years. In 1967 he joined the University of California, Santa Cruz as professor and almost immediately became acting director of the Lick Observatory. He served as acting director for a total of five years and later as director from 1981 to 1991. During the last three years of his directorship, he also led the University of California Observatories, which included the University of California’s share of the Keck Observatory. A stellar spectroscopist, he used Cepheid variable stars to measure interstellar absorption and obtain distances to clusters, and he made a definitive study of stellar rotations. He showed that all dwarf novae and ordinary novae are close binary stars, some with orbital periods little more than an hour. As early as 1962 he considered gravitational radiation as the cause of the evolution of a close binary. He worked with many collaborators to determine the chemical composition of different types of evolved stars in the galactic halo and globular clusters in an effort to determine the evolution of baryonic matter in the Galaxy. He was widely respected as both an administrator and a teacher.

Other awards

American Astronomical Society, Helen B. Warner Prize, 1962; Henry Norris Russell Lectureship, 1995.

Some offices held

American Astronomical Society, President, 1974-76.
International Astronomical Union, President, 1997-2000.

Biographical materials

Kraft, Robert P., “Thoughts on Receiving the Bruce Medal,” Mercury 34, 6, 32-34 (Nov/Dec 2005).
Kraft, Robert P., “An Astronomical Life Salted by Pure Chance,” Ann. Revs. Astron. Astrophys. 47, 1-26 (2009).


Pilachowski, Catherine A., Duane F. Carbon, Eileen Freel, Christian I. Johnson, & Matthew Shetrone, PASP 978, id 080201 (2017).
Santa Cruz Sentinel, 30 May 2015.
Stephens, Tim, University of California, Santa Cruz, 28 May 2015.
Woo, Elaine, Los Angeles Times, 1 June 2015

Academic genealogy



2005, courtesy of Dr. Kraft
AIP Center for History of Physics (several)

Named after him

Minor Planet #3712 Kraft


Papers, etc.

There is an oral history interview at the Niels Bohr Library & Archives.

Other References: Historical

Osterbrock, Donald E., John R. Gustafson, and W.J. Shiloh Unruh, Eye on the Sky : Lick Observatory's First Century (Univ. of California Press, Berkeley, 1988).

Secco, L., On Kraft’s Model for Cataclysmic Variables (Villaggio del Fanciullo, Trieste, 1968).

Search ADS for works about Kraft

Other References: Scientific

Jacobsen, T.S. & R.P. Kraft, “The Spectrographic Orbit of HD 198784,” Publ. Dominion Astrophys. Obs. Victoria 8, 129-34 (1949).

Struve, O., D. H. McNamara, S.M. Kung, R. P. Kraft, & A.D Williams, “The Radial Velocity of Nu Eridani,” Ap.J. 116, 398-409 (1952).

Crawford, John A. & Robert P. Kraft, “An Intrepretation of AE Aquarii,” Ap.J. 123, 44-53 (1956). [This may be the first paper to deal with an accretion disk in a close binary system.]

Kraft, Robert P., “The Binary System Nova T Coronae Borealis,” Ap.J. 127, 625-41 (1958).

Greenstein, Jesse L. & Robert P. Kraft, “The Binary System Nova DQ Herculis. I. The Spectrum and Radial Velocity during the Eclipse Cycle” Ap.J. 130, 99-109 (1959).

Kraft, Robert P., “The Binary System Nova DQ Herculis. II. An Interpretation of the Spectrum during the Eclipse Cycle” Ap.J. 130, 110-22 (1959).

Kraft, Robert P., “Color Excesses for Supergiants and Classical Cepheids” Ap.J. 131, 330-50 (1960)132, 404-16 (1960); and 133, 39-56 (1960).

Kraft, Robert P., “Binary Stars among Cataclysmic Variables. I. U Geminorum Stars (Dwarf Novae)., ” Ap.J. 135, 408-23 (1962).

Kraft, Robert P., Jon Mathews, Jesse L. Greenstein, “Binary Stars among Cataclysmic Variables. II. Nova WZ Sagittae: A Possible Radiator of Gravitational Waves,” Ap.J. 136, 312-314 (1962).

Kraft, Robert P.,, “Binary Stars among Cataclysmic Variables. III. Ten Old Novae,” Ap.J. 139, 457-75 (1964).

Kraft, Robert P., George W. Preston, & Sidney Carne Wolff, “The Width of H-Alpha as a Discriminant of Luminosity in the Spectra of Late-Type Stars, ”Ap.J. 140, 235-49 (1964).

Kraft, Robert P., “Studies of Stellar Rotation. I. Comparison of Rotational Velocities in the Hyades and Coma Clusters,” Ap.J. 142, 681-702 (1965).

Kraft, Robert P., “The Line Spectrum of Pulsating Variable Stars,” in Aerodynamic Phenomena in Stellar Atmospheres, Proceedings from Symposium no. 28 held at the Centre International d'Astrophysique de l’Observatoire de Nice, 2-14 September, 1965, ed. by Richard Nelson Thomas. International Astronomical Union Symposium no. 28 (Academic Press, London, 1967), p. 207-45.

Kraft, Robert P., “Studies of Stellar Rotation. IV. A Comparison of Rotational Velocities in the Alpha Persei Cluster and the Pleiades,” Ap.J. 148, 129-40 (1967).

Kraft, Robert P., “Studies of Stellar Rotation. V. The Dependence of Rotation on Age among Solar-Type Stars,” Ap.J. 150, 551-70 (1967).

Kraft, R.P., “Stellar Rotation,” in Stellar Astronomy, Proceedings of the Summer Institute for Observational Astronomy, held at the State University of New York at Stony Brook, Summer 1967, ed. by Hong-Yee Chiu, Robert L. Warasila, and John L. Remo (Gordon and Breach, New York, 1969), p.317.

Kraft, Robert P., W. Krzeminski, & George S. Mumford, “Binary Stars among Cataclysmic Variables. XI. Photoelectric and Spectroscopic Observations of the Dwarf Nova Z Camelopardalis, ” Ap.J. 158, 589-98 (1969).

Kraft, R.P., “Stellar Rotation,” in Spectroscopic Astrophysics: An Assessment of the Contributions of Otto Struve ed. by G.H. Herbig (University of California Press, Berkeley, 1970), p.385

Barker, Timothy, Leona D Baumgart, Dennis Butler, Kyle M. Cudworth, Edward Kemper, Robert P. Kraft, Jean Lorre, N. Kameswara Rao, Glenn H. Reagan, & David R. Soderblom, “Abundance Analysis of Population II Variable Stars. I. W Virginis, ” Ap.J. 165, 67-86 (1971).

Anderson, Kurt S. & Robert P. Kraft, “Abundance Analyses of Population II Variable Stars. II. TW Capricorni,” Ap.J. 167, 119-25 (1971).

Kraft, Robert P., “Observational Aspects of RR Lyrae and W Virginis Stars: Some Conundrums of Stellar Populations and Galactic Distribution,” in The Evolution of Population II Stars, Proceedings of a Conference Held at the State University of New York at Stony Brook, December, 1970, ed, by A. G. D. Philip, Dudley Observatory Report No. 4, 1972., p.69.

Kraft, Robert P., “Binary Systems as X-Ray Sources: A Review,“ in X- and Gamma-Ray Astronomy, Proceedings of IAU Symposium no. 55 held in Madrid, Spain, 11-13 May 1972, ed. by H. Bradt and Riccardo Giacconi (D. Reidel, Dordrecht & Boston, 1973), pp. 36-50.

Bregman, Jesse, Dennis Butler, Edward Kemper, Alan Koski, R.P. Kraft, & R.P.S. Stone, “On the Distance to Cygnus X-1 (HDE 226868),” Ap.J. 185, L117-L120 (1973).

Langer, G.E., Robert P. Kraft, & Kurt S. Anderson, “FG Sge: The s-Process Episode,” Ap.J. 189, 509-21 (1974).

Taam, Ronald E., Robert P. Kraft, & Nicholas Suntzeff, “The Origin and Evolution of RR Lyrae Stars of High Metal Abundance,” Ap.J. 207, 201-08 (1976).

Butler, Dennis, Duane Carbon, & Robert P. Kraft, “Metal Abundances of RR Lyrae Variables in Selected Galactic Star Fields. I. Baade’s Window,” Ap.J. 210, 120-28 (1976).

Butler, Dennis, T.D. Kinman, & Robert P. Kraft, “Metal Abundances of RR Lyrae Variables in Selected Galactic Star Fields. II. The Lick Astrograph Fields Near the North Galactic Pole,” Astronomical Journal 84, 993-1004 (1979) [erratum].

Kraft, Robert P., “On the Nonhomogeneity of Metal Abundances in Stars of Globular Clusters and Satellite Subsystems of the Galaxy,” Ann. Revs. Astron. Astrophys. 17, 309-43 (1979).

Kraft, Robert P., Charles F. Trefzger, & N. Suntzeff, “Is There a Composition Gradient in the Halo?” in The Large-Scale Characteristics of the Galaxy; Proceedings of the Symposium, College Park, Md., June 12-17, 1978 (D. Reidel, Dordrecht, 1979), 463-73.

Butler, Dennis, Edward Kemper, Robert P. Kraft, & N.B. Suntzeff, “Metal Abundances of RR Lyrae Variables in Selected Galactic Star Fields. III. The Lick Astrographic Fields Near the Galactic Anticenter,” Astronomical Journal 87, 353-59 (1982).

Kraft, Robert P., Nicholas B. Suntzeff, G.E. Langer, Duane F. Carbon, Charles F. Trefzger, Eileen Friel, & Remington P.S. Stone, “Carbon and Nitrogen Abundances in Extremely Metal-Deficient Red Giants, ” PASP 94, 55-66 (1982).

Carbon, Duane F., G.E. Langer, Dennis Butler, Robert P. Kraft, Nicholas B. Suntzeff, Edward Kemper, Charles F. Trefzger, & W. Romanishin, “Carbon and Nitrogen Abundances in Giant Stars of the Metal-Poor Globular Cluster M92, ”Ap.J. Suppl. 49, 207-58 (1982).

Kraft, R.P., “C, N, O Abundances in Old Stars of the Galactic Halo and in Stars of Small Satellite Subsystems of the Galaxy,” ”in ESO Workshop on Production and Distribution of C, N, O Elements, Garching, West Germany, May 13-15, 1985, Proceedings (European Southern Observatory, Garching, West Germany, 1985), p. 21-47 [abstract].

Langer, G.E., Robert P. Kraft, & Eileen D. Friel, “Bimodal Cyanogen Distributions in Moderately Metal-poor Globular Clusters. I - Carbon and Nitrogen Abundances for Six M5 Giants,” PASP 97, 373-81 (1985).

Suntzeff, Nicholas B., Eileen Friel, Arnold Klemola, Robert P. Kraft, & J.A. Graham, “The Stellar Population of the Small Magellanic Cloud near NGC 121. I. The Mean Metallicity, Metallicity Spread, and Radial Velocity of SMC Halo Giants,” Astronomical Journal 91, 275-89 (1986).

Carbon, Duane F., Beatrice Barbuy, Robert P. Kraft, Eileen D. Friel, & Nicholas B. Suntzeff, “Carbon and Nitrogen Abundances in Metal-Poor Dwarfs of the Solar Neighborhood, ” PASP 99, 335-68 (1987).

Kraft, Robert P., “Can We Derive the Chemical History of the Galaxy from the Study of Globular Cluster Stars?” in F. Bertola, J. W. Sulentic and B. F. Madore, eds., New Ideas in Astronomy: Proceedings of a Conference Held in Honor of the 60th Birthday of Halton C. Arp, Venice, Italy, May 5-7, 1987 (Cambridge University Press, 1988), pp. 23-40 [abstract].

Kraft, Robert P., “On the Halo Blue Star Mystery, ” PASP 101, 1113-20 (1989).

Suntzeff, Nicholas B., T.D. Kinman, & Robert P. Kraft, “Metal Abundances of RR Lyrae Variables in Selected Galactic Star Fields. V. The Lick Astrographic Fields at Intermediate Galactic Latitudes,” Ap.J. 367, 528-46 (1991).

Sneden, Christopher, Robert P. Kraft, Charles F. Prosser, & G.E. Langer, “Oxygen Abundances in Halo Giants. I. Giants in the Very Metal-Poor Globular Clusters M92 and M15 and the Metal-Poor Halo Field, ” Astronomical Journal 102, 2001-21 (1991).

Kraft, Robert P., Christopher Sneden, G.E. Langer, & Charles F. Prosser, “Oxygen Abundances in Halo Giants. II Giants in the Globular Clusters M13 and M3 and the Intermediate Metal-Poor Halo Field, ” Astronomical Journal 104, 645-68 (1992).

Sneden, Christopher, Robert P. Kraft, Charles F. Prosser, & G.E. Langer, “Oxygen Abundances in Halo Giants. III. Giants in the Mildly Metal-Poor Globular Cluster M5, ” Astronomical Journal 104, 2121 (1992).

Kraft, Robert P., Christopher Sneden, G.E. Langer, & Matthew D. Shetrone, “Oxygen Abundances in Halo Giants. IV. The Oxygen-sodium Anticorrelation in a Sample of 22 Bright Giants in M13 , ” Astronomical Journal 106, 1490-1507 (1993).

Stone, Remington P.S., Robert P. Kraft, & Charles F. Prosser, “The Optical Spectrum of FG Sagittae during its Recent Decline in Brightness,” PASP 105, 755-60 (1993).

Sneden, Christopher, Robert P. Kraft, G.E. Langer, Charles F. Prosser, & Matthew D. Shetrone, “Oxygen Abundances in Halo Giants. V. Giants in the Fairly Metal-Rich Globular Cluster M71, ” Astronomical Journal 107, 1773-85 (1994).

Kraft, Robert P., “Abundance Differences Among Globular-Cluster Giants: Primordial Versus Evolutionary Scenarios, ” PASP 106, 553-65 (1994).

Kinman, T.D., Jeffrey R. Pier, Nicholas B. Suntzeff, D.L. Harmer, F. Valdes, Robert B. Hanson, A.R. Klemola, & Robert P. Kraft, “A Preliminary Discussion of the Kinematics of BHB and RR Lyrae Stars Near the North Galactic Pole,” Astronomical Journal 111, 1164 (1996).

Suntzeff, Nicholas B. & Robert P. Kraft, “The Abundance Spread Among Giants and Subgiants in the Globular Cluster ω Centauri,” Astronomical Journal 111, 1913-35 (1996)

Pilachowski, Catherine A., Christopher Sneden, Robert P. Kraft, & G.E. Langer, “Proton Capture Chains in Glubular Cluster Stars. I. Evidence for Deep Mixing Based on Sodium and Magnesium Abundances in M13 Giants” Astronomical Journal 112, 545-64 (1996).

Hanson, Robert B., Christopher Sneden, Robert P. Kraft, & Jon Fulbright, “On the Use of [Na/Fe] and [α/Fe] Ratios and Hipparcos-based (U, V, W) Velocities as Age Indicators among Low-Metallicity Halo Field Giants,” Astronomical Journal 116, 1286-94 (1998).

Kraft, Robert P., Ruth C. Peterson, Puragra Guhathakurta, Christopher Sneden, Jon P. Fulbright, & G. Edward Langer, “An Extremely Lithium-Rich Bright Red Giant in the Globular Cluster M3, ” Ap.J. 518, L53-L56 (1999).

Ivans, Inese I., Christopher Sneden, Robert P. Kraft, Nicholas B. Suntzeff, Verne V. Smith, G. Edward Langer, & Jon P. Fulbright, “Star-to-Star Abundance Variations among Bright Giants in the Mildly Metal-poor Globular Cluster M4,” Astronomical Journal 118, 1273-1300 (1999).

Sneden, Christopher, Jennifer Johnson, Robert P. Kraft, Graeme H. Smith, John J. Cowan, & Michael S. Bolte, “Neutron-Capture Element Abundances in the Globular Cluster M15, ” Ap.J. 536, L85-L88 (2000).

Sneden, Christopher, Catherine A. Pilachowski, & Robert P. Kraft, “Barium and Sodium Abundances in the Globular Clusters M15 and M92,” Astronomical Journal 120, 1351-63 (2001).

Ivans, Inese I., Robert P. Kraft, Christopher Sneden, Graeme H. Smith, R. Michael Rich, & Matthew Shetrone, “New Analyses of Star-to-Star Abundance Variations among Bright Giants in the Mildly Metal-poor Globular Cluster M5,” Astronomical Journal 122, 1438-63 (2001).

Kraft, Robert, “A Comparison of Globular Cluster and Halo Field Stars, in” in Astrophysical Impact of Abundances in Globular Cluster Stars, 25th meeting of the IAU, Joint Discussion 4, 16-17 July 2003, Sydney, Australia [abstract].

Kraft, Robert P. & Inese I. Ivans, “A Globular Cluster Metallicity Scale Based on the Abundance of Fe II,” PASP 115, 143-69 (2003).

Kraft, Robert P., “A Comparison of Globular Cluster and Halo Field Stars,” Memorie della Societa Astronomica Italiana75, 295-97 (2004).

Kraft, R.P. & I.I. Ivans, “A New Globular Cluster Metallicity Scale Based on the Abundance of Fe II, ” in Carnegie Observatories Astrophysics Series, Vol. 4: Origin and Evolution of the Elements, ed. by A. McWilliam and M. Rauch (Carnegie Observatories, Pasadena, 2004), pp. 1-10.

Sneden, Christopher, Robert P. Kraft, Puragra Guhathakurta, Ruth C. Peterson, & Jon P. Fulbright, “The Chemical Composition Contrast between M3 and M13 Revisited: New Abundances for 28 Giant Stars in M3,” Astronomical Journal 127, 2162-84 (2004).

Johnson, Christian I., Robert P. Kraft, Catherine A. Pilachowski, Christopher Sneden, Inese I. Ivans, & Gabriel Benman, “A 235 Star Sample Sodium, Magnesium, and Aluminum Abundance Study in the Globular Clusters M3 (NGC 5272) and M13 (NGC 6205),” PASP 117, 1308-24 (2005).

Sobeck, Jennifer S.; Inese I. Ivans, Jennifer A. Simmerer, Christopher Sneden, Peter Hoeflich, Jon P. Fulbright, & Robert P. Kraft, “Manganese Abundances in Cluster and Field Stars,” Astronomical Journal 131, 2949-58 (2006).

Sobeck, J.S., R. Kraft, & C. Sneden “Metallicity Discrepancy between RGB and RHB Stars of the Globular Cluster M15,”in Brian W. O'Shea, Alexander Heger, & Tom Abel, eds., FIRST STARS III: Santa Fe NM, 15-20 July 2007. AIP Conference Proceedings, Vol. 990, (Amer. Inst. of Phys., Melville, NY, 2008), pp. 184-186.

Lai, David K., et al., “Chemical Abundances for Evolved Stars in M5: Lithium through Thorium,” Astronomical Journal 141, id 62, 1-20 (2011).

Sobeck, Jennifer S., et al., “The Abundances of Neutron-capture Species in the Very Metal-poor Globular Cluster M15: A Uniform Analysis of Red Giant Branch and Red Horizontal Branch Stars,” Astronomical Journal 141, id 175 1-18 (2011).

Marino, A.F., et al., “The Double Sub-giant Branch of NGC 6656 (M 22): A Chemical Characterization,” Astronomy & Astrophysics 541, id A15 1-18 (2012).

Search ADS for works by Kraft [some of the papers by “R.P. Kraft” after 1990 are by Ralph P. Kraft, an X-ray astronomer at the Smithsonian Astrophysical Observatory.]

Other Works: History of Astronomy, Popularizations, etc.

Kraft, Robert P., “Exploding Stars,”Scientific American 206, 4, 54-63 (Apr. 1962).

Kraft, Robert P., “Are all Novae Binary Stars?” Leaflets of the Astronomical Society of the Pacific 9, 137-44 (1964) [Leaflet #418].

Kraft, Robert P., “FG Sagittae: Rosetta Stone for Nucleosynthesis?” Sky & Telescope 48, 18 (1974).

Kraft, Robert P., “Pulsating Stars and Cosmic Distances,” in The New Astronomy and Space Science Reader, ed. by John C. Brandt and Stephen P. Maran (W.H. Freeman, San Francisco, CA, 1977), p.152

Kraft, Robert P., “Licking the Light Pollution, ”Sky & Telescope 68, 492 (1984).

Kraft, Robert P., “Helfer, Wallerstein, & Greenstein’s Abundances in Population II Giants,” Ap.J.525C, 896 (1999).