Astrophysical and Planetary Sciences

Astrophysical and Planetary Sciences at the University of Colorado Boulder offers a comprehensive and rigorous program designed to prepare students for careers in the fields of astronomy, astrophysics, planetary science, and space research. This program combines theoretical fundamentals with practical research opportunities, allowing students to explore the universe's origins, composition, and dynamic processes. Students engage with a diverse curriculum covering areas such as stellar astrophysics, planetary geology, cosmology, observational techniques, and data analysis. Through coursework, laboratory work, and hands-on experiences, students develop a solid understanding of physical principles and technological tools necessary to investigate celestial phenomena. The program emphasizes research excellence and encourages students to participate actively in faculty-led projects, internships, and conferences, fostering skills in scientific communication and collaboration. Graduates are well-prepared for careers in academia, government agencies, research institutions, and private industry, working on topics ranging from planetary exploration to observational astronomy. The program's state-of-the-art facilities and close ties with NASA and other agencies provide unique opportunities for internships, collaborations, and access to cutting-edge technology. Students also benefit from seminars, workshops, and mentoring programs designed to cultivate interdisciplinary thinking and innovative problem-solving abilities. With faculty renowned in their fields, the Astrophysical and Planetary Sciences program at CU Boulder aims to cultivate the next generation of scientists who will contribute to our understanding of the universe and the origins of planetary systems, guiding humanity’s quest to explore beyond our planet.

Prerequisites. A thorough undergraduate preparation in physics and mathematics is necessary for graduate study. Courses should include thermodynamics, mechanics, electricity and magnetism, quantum mechanics, atomic physics and mathematics at least through complex variables and differential equations.

Qualifying Examination. The Graduate Record Examination aptitude tests and advanced test in physics are used in place of a qualifying examination, and this examination should be taken before the time of application to the department. 

Preliminary Interview. Students in the Department of Astrophysical and Planetary Sciences are given an oral interview prior to the beginning of the fall semester of their first year. This oral interview examines fundamental knowledge in undergraduate physics and mathematics. Students are required to overcome any academic deficiencies within a year in order to remain in the program.

Course Requirements. Under Plan I, a student must present a thesis for 6 credit hours plus 24 credit hours of course work, at least 12 of which must be APS courses numbered 5000 or above. Under Plan II, additional hours of approved graduate courses must be presented for a total of 30 credit hours, of which at least 16 must be APS courses numbered 5000 or above. The master’s examination under Plan I covers the thesis and related topics. The examination under Plan II is more comprehensive and may be either written or oral or both. Master’s examinations are given after other degree requirements have been completed, but may be given during the last semester of residence if the student is making satisfactory progress on required courses. 

Course Requirements. A minimum of 39 semester hours of work (including 4 hours of graduate seminars) in courses numbered 5000 or above is required; however, the overall emphasis is on independent study and research. A minimum of 30 semester hours of PhD dissertion credits are required.

Language Requirement. None.

Examinations. Students in the PhD program are required to remove any deficiencies identified at the preliminary interview, to pass a two-part comprehensive examination composed of a written test on graduate course material and an oral exam on a research paper based on a semi-independent research project, and satisfactorily defend the thesis before a faculty committee.The department offers the PhD degree. During the first year of graduate study, students generally obtain a broad background in courses regarded as basic to all three areas in addition to more specialized studies. Many students take graduate-level courses in other departments (e.g., Departments of Physics, Atmospheric and Oceanic Sciences, Geological Sciences, Applied Mathematics or Aerospace Engineering), depending upon their particular interests or participation in interdisciplinary programs (see below). The departmental core courses in the three areas are:

• ASTR 5110 Atomic and Molecular Processes 
• ASTR 5120 Radiative and Dynamical Processes 
• ASTR 5400 Introduction to Fluid Dynamics
• ASTR 5540 Mathematical Methods
• ASTR 5550 Observations, Data Analysis and Statistics

Descriptions of more specialized courses follow. Students interested in applying to this department are invited to write to Graduate Program Assistant, Department of Astrophysical and Planetary Sciences, University of Colorado Boulder, 391 UCB, Boulder, CO 80309-0391.

Astrophysics

The department offers a broad range of courses and research in this area, leading to the PhD degree. Graduate-level courses are offered in the following subjects:

• ASTR 5140 Astrophysical and Space Plasmas
• ASTR 5700 Stellar Structure and Evolution
• ASTR 5710 High-Energy Astrophysics
• ASTR 5720 Galaxies
• ASTR 5730 Stellar Atmospheres and Radiative Transfer
• ASTR 5740 Interstellar Astrophysics
• ASTR 5760 Astrophysical Instrumentation
• ASTR 5770 Cosmology
• ASTR 6000 Seminar in Astrophysics

Research in observational and theoretical astrophysics is conducted in the following areas:

• Stellar atmospheres, radiative transfer, stellar winds of hot/cool stars
• Formation of stars and planetary systems
• Solar physics
• Interstellar and intergalactic medium
• Cosmology and large-scale structure of the universe; galaxy formation
• Stellar interiors, black holes and neutron stars
• Gravitational physics
• Cosmic X-ray sources, supernovae and their remnants and accretion phenomena, jets and clusters of galaxies
• Galactic evolution, quasars and active galaxies
• Radio and sub-millimeter astronomy, microwave background
• Plasma astrophysics and MHD
• Astrophysical fluid dynamics
• UV, optical, IR, submillimeter, radio and X-ray instrumentation
• Instrument and detector development
• Sounding rocket and balloon astronomy

Departmental Equipment and Research. Research is carried out with the ARC 3.5m Apache Point telescope and with national telescopes and laboratories and international collaborators: High Altitude Observatory (HAO) in Boulder (solar physics), National Optical Astronomical Observatories in Tucson and Chile (optical astronomy), Caltech Sub-Millimeter Observatory, National Radio Astronomy Observatory (NRAO), the Very Large Array (VLA), the Green Bank Telescope (GBT), the Hubble Space Telescope (HST), the Chandra, SWIFT, and XMM X-ray telescopes, the Fermi Gamma-Ray Space Telescope and the National Solar Observatory (NSO). CU-Boulder also is involved with the Messenger (Mercury), MAVEN (Mars), JUNO (Jupiter), Cassini (Saturn) and New Horizons (Pluto) missions, and the HST Cosmic Origins Spectrograph.

Locally, APS operates a 24-inch Cassegrain-Coude and 16- and 18-inch Cassegrain telescopes through Sommers-Bausch Observatory, available for photographic, photometric and spectrographic observations, as well as for instrument and detector development. Opportunities for graduate research also are found with the university’s Laboratory for Atmospheric and Space Physics (LASP), the Center for Astrophysics and Space Astronomy (CASA) and JILA. See Graduate School for more information. 

Planetary Sciences

As planetary sciences is an interdisciplinary field, students can obtain degrees from the Departments of Astrophysical and Planetary Sciences, Atmospheric and Oceanic Sciences, Geological Sciences, Physics or Aerospace Engineering. Boulder is also home to a division of the Southwest Research Institute, with over 25 planetary scientists, many of whom work with CU students. Research and courses related to the physics and dynamics of the atmospheres of other planets, planetary surfaces and interiors and other solar system studies are available in programs leading to the MS and PhD degrees. Courses related to the physics and dynamics of the Earth’s atmosphere are offered through ATOC. Graduate-level courses in these areas are:

• ASTR 5140 Astrophysical and Space Plasma
• ASTR 5300 Introduction to Magnetospheres
• ASTR 5330 Cosmochemistry
• ASTR 5410 Fluid Instabilities, Waves and Turbulence
• ASTR 5800 Planetary Surfaces and Interiors
• ASTR 5810 Planetary Atmospheres
• ASTR 5820 Origin and Evolution of Planetary Systems
• ASTR 5830 Topics in Planetary Science
• ASTR 5835 Seminar in Planetary Science
• ATOC 5050 Physical Processes of the Atmosphere and Ocean
• ATOC 5560 Radiative Processes in Planetary Atmospheres
• ATOC 5960 Theories of Climate and Climate Variability

Research in theoretical, observational and laboratory atmospheric and planetary science is conducted in the following areas:

• Planetary disks, Kuiper Belt objects, extra-solar planets;
• Dynamics and chemistry of planetary atmospheres, planetary clouds and planetary climates; evolution of planetary atmospheres; and comparison of planetary and terrestrial atmospheres;
• Planetary aeronomy, airglow and aurora, UV and IR spectroscopy, noctilucent clouds, structure and composition of planetary atmospheres (Venus, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto), planetary magneto-spheres and cometary physics;
• Satellite monitoring of the Earth’s atmosphere and environment, including remote sensing of mesospheric ozone, stratospheric trace species, convection, outgoing radiation and magnetospheric dynamics; and
• Planetary geology, planetary interiors and surfaces and planetary geophysics.

Graduate research opportunities exist with individual faculty members, as well as jointly with academic and research units such as the Departments of Geological Sciences, Physics and Aerospace Engineering, as well as the Department of Atmospheric and Oceanic Sciences (ATOC), the National Center for Atmospheric Research (NCAR), the National Oceanic and Atmospheric Administration (NOAA) and the Laboratory for Atmospheric and Space Physics (LASP). The latter is involved in space investigations of the Earth, Sun and planets. Financial support is available in connection with all of the above research activities

Requirements

1. Hold a baccalaureate degree from an accredited college or university.
2. Have an undergraduate GPA of at least 3.00.
3. Submit three letters of recommendation;
4. Submit directly from ETS test scores from the verbal, quantitative and analytical writing sections of the General Record Examination (GRE), as well as the Physics GRE.

There is no pre-application, but we strongly urge all applicants to have a strong physics and mathematics background, as well as a strong GPA, and strong GRE scores.GRE minimum scores of verbal 75 percent, quantitative 85 percent, analytical 75 percent. Advanced GRE minimum score approximately 40 percent.

Scholarships

• Financial support is available to all incoming students through teaching or research assistantships. Fellowships are also available upon acceptance.

The Astrophysical and Planetary Sciences program at the University of Colorado Boulder offers students a comprehensive education in understanding the physical properties and dynamic processes of celestial bodies and phenomena. This interdisciplinary program combines principles of physics, astronomy, geology, and planetary sciences to provide students with a broad perspective on the universe and our place within it. The curriculum includes coursework in celestial mechanics, star formation, planetary geology, cosmology, and observational techniques, preparing students for research and careers in academia, industry, or government agencies. Students have access to state-of-the-art telescopes and laboratories, enabling hands-on experience in data collection and analysis. The program emphasizes both theoretical understanding and practical skills, fostering critical thinking and problem-solving abilities. Faculty members are experts in their fields, actively engaged in research projects related to planetary systems, exoplanets, and space exploration. Opportunities for internships, fieldwork, and collaboration with space agencies like NASA are available to enrich the educational experience. Graduates of the program are well-equipped for pursuing graduate studies or entering professional roles in astrophysics, planetary science, aerospace engineering, and science communication. The program aims to develop a strong foundation in scientific inquiry, quantitative analysis, and research methodology, ensuring students are prepared to contribute meaningfully to the scientific community and to society's broader understanding of space phenomena.