Students pursuing a PhD from the Department of Astrophysical and Planetary Sciences generally specialize in the areas of astrophysics or planetary science. 

The department does not offer a terminal, stand-alone master's degree program. Students enrolled in the doctoral program may earn their master's degree as they progress toward their PhD.

The program successfully integrates astrophysics, planetary science, Solar physics, and space instrumentation with strong observational and theoretical components. These assets facilitate interaction and collaboration between the disciplines and enable students to explore a wide variety of research areas.

The Sommers­-Bausch Observatory, conveniently located on campus, provides excellent hands­-on experience with telescopes and observing, while the world­-class Fiske Planetarium, supported by our department, offers a unique opportunity for public outreach. These campus resources are complemented by other affiliated research organizations in Boulder.

For more information, visit the department's Prospective Students webpage.


A minimum of 37 credit hours of coursework (including 4 credit 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 credit hours of PhD dissertation credit hours are required.

Students in the PhD program are required to remove any deficiencies identified at the preliminary interview; to pass a comprehensive examination composed of writing a research paper based on a semi-independent research project, then an oral exam on that paper and related topics within the field; and to satisfactorily defend the PhD thesis before a faculty committee.

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).

Required Courses and Credits

ASTR 5110Atomic and Molecular Processes3
ASTR 5540Mathematical Methods3
ASTR 5400Introduction to Fluid Dynamics3
ASTR 5550Observations, Data Analysis and Statistics3
ASTR 5120Radiative and Dynamical Processes3
Total Credit Hours15

Electives: Astrophysics Focus

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 5140Astrophysical and Space Plasmas3
ASTR 5700Stellar Astrophysics3
ASTR 5710High-Energy Astrophysics3
ASTR 5720Galaxies3
ASTR 5730Stellar Atmospheres and Radiative Transfer3
ASTR 5760Astrophysical Instrumentation3
ASTR 5770Cosmology3
ASTR 6000Seminar in Astrophysics1

Electives: Planetary Sciences Focus

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.

Graduate-level courses related to the physics and dynamics of the Earth's atmosphere are offered in the following subjects:

ASTR 5140Astrophysical and Space Plasmas3
ASTR 5300Introduction to Magnetospheres3
ASTR 5330Cosmochemistry3
ASTR 5410Fluid Instabilities, Waves, and Turbulence3
ASTR 5800Planetary Surfaces and Interiors3
ASTR 5810Planetary Atmospheres3
ASTR 58203
ASTR 5830Topics in Planetary Science3
ASTR 5835Seminar in Planetary Science1
ATOC 5050Atmospheric Thermodynamics and Dynamics3
ATOC 5560Radiative Processes in Planetary Atmospheres3

Research Opportunities

Observational and Theoretical Astrophysics

Research in this field 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

Research is carried out with the ARC 3.5m Apache Point telescope, the Sloan Digital Sky Survey-V and these 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); 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 Daniel K. Inouye Solar Telescope (DKIST) through collaboration with National Solar Observatory (NSO). CU Boulder also is involved with the Messenger (Mercury), MAVEN (Mars), JUNO (Jupiter), Cassini (Saturn), and New Horizons (Pluto) missions, as well as the HST Cosmic Origins Spectrograph.

Locally, APS operates a 24-inch Cassegrain-Coude and two 20-inch Cassegrain telescopes through Sommers-Bausch Observatory. These are 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.

Theoretical, Observational and Laboratory Atmospheric and Planetary Science

Research in this field 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; 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 magnetospheres, 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
  • 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.