Astrophysical and 
Planetary Sciences

Degrees BA, MS, PhD

The undergraduate major has two tracks—one in general astronomy and one in astrophysics/physics (see the website at

The track in general astronomy is designed to meet student needs for basic, undergraduate training in space sciences (astronomy, astrophysics, planetary sciences, and space physics). Undergraduates are prepared for both academic research careers and the industrial market (aerospace, computer software, instrumentation, and other technical areas) as well as for science education, science journalism, and space policy. This track provides a liberal arts degree in the science of astronomy, observations, and technology as well as core training in astronomical sciences and mathematics, applied physics, and computational and instrumental technology for professions in the space sciences. The track can focus on observations (ground-based telescopes, rocket probes, space-borne observatories) or on K–12 science education, for which astronomy provides excellent science content for motivating young students. It also offers broad training for careers in science policy and science writing.

The bachelor’s degree track in astrophysics/physics is directed toward students interested in pursuing graduate studies in astrophysics by focusing on multidisciplinary work in physics and mathematics together with astronomy. Graduates are provided with scientific and technological training in the space sciences, including mathematical, physical, computational, and instrumental expertise. A senior thesis or other research work is encouraged.

Specific goals for both programs are to provide:

• both theoretical and practical knowledge of astronomy and astrophysics at a level comparable to the best programs at other major U.S. public institutions. The Department of Astrophysical and Planetary Sciences is one of the few programs that combines both astrophysics and planetary science, providing a unified view of space sciences, the solar system and comparative planetology, stellar and galactic astronomy, and cosmology.
• courses and significant hands-on experience with telescopes, optics, instrumentation, and computer image processing and modeling. These skills are useful for students wishing to pursue graduate degrees or careers in aerospace, technical, or computer industries.
• opportunities for faculty-advised research and senior (honors) theses.

Bachelor’s Degree Program +

A major with two tracks (general astronomy and astrophysics/physics) was approved by the Regents and CCHE on June 1, 2000.

General Astronomy Track +

This is appropriate for someone aiming for a career in K–12 education, science journalism, science policy, information technology, science management, or technical work that does not require a graduate degree.

ASTR 1030 and 1040 Accelerated Introductory Astronomy or ASTR 1010 and 1020 Introductory Astronomy 8
PHYS 1110, 1120, and 1140 General Physics 1 and 2 9
APPM 1350 and 1360 or MATH 1300 and 2300 Calculus 1 and 2 8-10

One of the following four courses:
ASTR/ASEN 2500 Gateway to Space 3
ASTR 2600 Computational Techniques 3
PHYS 2130 General Physics 3
PHYS 2170 Foundations of Modern Physics 3

Minimum of two additional courses selected from:
ASTR 2000 Ancient Astronomies 3
ASTR 2010 Modern Cosmology 3
ASTR 2020 Introduction to Space Astronomy 3
ASTR 2030 Black Holes 3
ASTR 2500 Gateway to Space 3
ASTR 2600 Computational Techniques 3
ASTR 3300 Extraterrestrial Life 3

One other science sequence with lab. Can be satisfied by any sequence that satisfies arts and sciences core curriculum in natural sciences with lab, for example:
CHEM 1113, 1114, and 1131, 1134; EBIO 1210–1230, GEOL 1010, 1020, and 1030, ATOC 1050, 1060, and 1070, or equivalent 7-10

One upper-division course sequence:
ASTR 3720 Planets and their Atmospheres and ASTR 3750 Planets, Moons, and Rings or
ASTR 3730 Astrophysics 1: Stellar and Interstellar and ASTR 3830 Astrophysics 2: Galactic and Extragalactic 6

Four additional courses from the following or from those sequence courses not used for the upper-division sequence requirement, above :
ASEN 4010 Introduction to Space Dynamics 3
ASTR 3510 Observations and Instrumentation 1 4
ASTR 3520 Observations and Instrumentation 2 4
ASTR 3710 Formation and Dynamics of Planetary Systems 3
ASTR 3740 Cosmology and Relativity 3
ASTR 3760 Solar and Space Physics 3
ASTR 3800 Scientific Data Analysis and Computing 3
ASTR 4330 Cosmochemistry 3
ASTR 4800 Space Practice and Policy 3
ASTR 5760 Astrophysical Instrumentation (with instructor’s permission) 3
ATOC 4720 Atmospheric Physics and Dynamics 3

A minor is available that may be satisfied by taking various combinations of courses among the diverse possibilities offered by the department (see below).

Astrophysics/Physics Track (Jointly Supervised by the APS and Physics Departments) +

For students aiming for a graduate program in astronomy or planetary sciences. Similar to Physics Plan 2 (Astrophysics), with additional astrophysics instrumentation labs and different electives.

Required Courses Semester Hours
APPM 1350, 1360, 2350, and 2360 Calculus 1, 2, 3, and 4 or MATH 1300, 2300, 2400, and APPM 2360 Analytic Geometry and Calculus 1, 2, and 3 and Introduction Differential Equations with Linear Algebra 16-18
ASTR 1030 and 1040 Accelerated Introductory Astronomy 8
ASTR 3720 and 3750 planetary sequence or ASTR 3730 and 3830 stellar/galactic sequence 6
PHYS 1110, 1120, and 1140 General Physics 1 and 2 and PHYS 2150, 2170, and 2210 Sophomore Physics 16
PHYS 3310 and 3320 Electromagnetism and PHYS 3210 and 3220 Classical and Quantum Mechanics 12

Suggested electives: PHYS 4230 Thermodynamics and Statistical Mechanics or PHYS 4410 Quantum Mechanics II or PHYS 4420 Nuclear and Particle Physics or PHYS 4510 Optics or PHYS 4150 Plasma Physics

Three additional courses from the following or any of 3720, 3750, 3730, 3830 not used for the requirement above:
ASEN 4010 Introduction to Space Dynamics 3
ASTR 3510 Observations and Instrumentation 1 4
ASTR 3520 Observations and Instrumentation 2 4
ASTR 3710 Formation and Dynamics of Planetary Systems 3
ASTR 3740 Cosmology and Relativity 3
ASTR 3760 Solar and Space Physics 3
ASTR 3800 Scientific Data Analysis and Computing 3
ASTR 4010/4020 Senior Research Practicum 3 each
ASTR 4330 Cosmochemistry 3
ATOC 4720 Atmospheric Physics and Dynamics 3

Any 5000- or 6000-level physical and planetary sciences course with instructor’s permission 3
Total credit hours for the major 23 hours minimum in astrophysics and 28 hours minimum in physics (this must include at least 15 upper-division hours in astrophysics and 12 in physics).

Minor Program +

Declaration of a minor in astrophysical and planetary sciences is open to any student enrolled at CU-Boulder, regardless of college or school. For more information see

A total of 18 credit hours is required for the minor, at least 9 of which must be taken at the upper-division (3500 and above) level. For guidance, see an astrophysical and planetary sciences (APS) faculty advisor or request written information from the departmental office.

Graduate Degree Programs +

The curriculum and research in the department emphasizes three major areas: astrophysics, planetary sciences, and space physics.

The department offers both MS and PhD degrees. 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, Chemistry and Biochemistry, Geological Sciences, Applied Mathematics, or Aerospace Engineering), depending upon their particular interests or participation in interdisciplinary programs (see below). The basic first-year 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 at Boulder, 391 UCB, Boulder, CO 80309-0391.

Astrophysics (Including Solar Physics) +

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, pulsations, black holes, and neutron stars
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
Laboratory and atomic astrophysics
UV, optical, IR, submillimeter, and X-ray instrumentation
Instrument and detector development

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, and the Fermi Gamma-Ray Space Telescope. CU-Boulder also is involved with the FUSE ultraviolet satellite, Cassini, Galileo, 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, 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, Geological Sciences, Physics, or Aerospace Engineering. CU-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 PAOS under the ATOC acronym. 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 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; 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.

Atmospheric and Oceanic Sciences +

This interdisciplinary program provides an educational and research environment to examine the dynamical, physical, and chemical structures of the atmosphere, ocean, and land surface, and the manner in which they interact. For further information, see the ATOC listing. APS participates in the master’s degree program in computational science (under applied math).

Geophysics +

The department participates in the interdepartmental PhD program in geophysics. For further information, refer to the discussion of the geophysics program in the Graduate School section.

Departmental Requirements +

Those wishing to pursue graduate work in APS leading to candidacy for an advanced degree should carefully read requirements for advanced degrees in the Graduate School section. The following are special departmental requirements.

Master’s Degree +

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.

Doctoral Degree +

In addition to the master’s degree requirements above, PhD students must complete the following.

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.

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.

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