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Caltech
Division of Physics, Mathematics and Astronomy

Andrew W. Howard

Professor of Astronomy; Executive Officer for Astronomy
B.S., Massachusetts Institute of Technology, 1998; M.A., Harvard University, 2001; Ph.D., 2006. Professor, Caltech, 2016-; Executive Officer, 2023-.

Research Interests: Extrasolar Planets, Instrumentation, SETI

Overview

Professor Howard is interested in the formation and evolution of extrasolar planets, i.e. planets orbiting stars other than the Sun. Using telescopes in Hawaii, California, and in space, his research group discovers and characterizes planets to determine their physical and orbital characteristics. With thousands of planetary systems for comparison, our Solar System is placed in a broader context.

A particular focus of Howard's research is the diversity of small planets. Within our Solar System, Neptune and Earth are the archetypal small planets, representing low-density ice giants and high-density rocky planets. In extrasolar systems we see a much greater diversity of structure and composition owing to broadly varying admixtures of the basic planetary ingredients of hydrogen gas, water, rock, and iron. 

Selected Awards

  • Cozzarelli Prize, Top Paper in the Physical and Mathematical Sciences in PNAS, Prevalance of Earth-size Planets orbiting Sun-like Stars, 2014
  • University of Hawaii Regents' Medal for Excellence in Research, 2014

Leadership

PhD Thesis: Astronomical Searches for Nanosecond Optical Pulses

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Selected Publications

For a complete publications list, see feeds.library.caltech.edu

Related Courses

Ay 122 abc. Astronomical Measurements and Instrumentation. 9 units (3-0-6); first, third terms, 2025-26. Prerequisites: Ph 106 bc or equivalent. Measurement and signal analysis techniques throughout the electromagnetic spectrum. Courses may include lab work and field trips to Caltech observatories. Ay 122 a concentrates on infrared, optical, and ultraviolet techniques: telescopes, optics, detectors, photometry, spectroscopy, active/adaptive optics, coronography. Imaging devices and image processing. Ay 122 b concentrates on radio through submillimeter techniques: antennae, receivers, mixers, and amplifiers. Interferometers and aperture synthesis arrays. Signal analysis techniques and probability and statistics, as relevant to astronomical measurement. Ay 122 c concentrates on X-ray through gamma-ray techniques. Part b not offered 2025-26.
Instructors: Howard, Kasliwal, Ravi
Ay/Ge 198. Special Topics in the Planetary Sciences. 6 units (2-0-4); third term, 2025-26. Topic for 2024-25 is Extrasolar Planets. Thousands of planets have been identified in orbit around other stars. Astronomers are now embarking on understanding the statistics of extrasolar planet populations and characterizing individual systems in detail, namely star-planet, planet-planet and planet-disk dynamical interactions, physical parameters of planets and their composition, weather phenomena, etc. Direct and indirect detection techniques are now completing the big picture of extra-solar planetary systems in all of their natural diversity. The seminar-style course will review the state of the art in exoplanet science, take up case studies, detail current and future instrument needs, and anticipate findings.
Instructor: Howard
Ay 30. Introduction to Modern Research. 3 units (2-0-1); first term, 2025-26. Open to declared Ay majors. At the discretion of the instructor, nonmajors who have taken astronomy courses may be admitted. Course is intended for sophomores and juniors. This weekly seminar-style discussion is held in faculty homes in the evening, and is designed to encourage student communication skills as they are introduced to faculty members and their research. Each week a student will review a popular-level article or general topic in astronomy for the class. Fulfills the Institute oral scientific communications requirement. Graded pass/fail.
Instructor: Howard