Caltech Astronomy Graduate School Application FAQ

Are you considering graduate study in astronomy at Caltech? Here are answers to some of the basic questions about the department. If you have a question not answered here, please contact the chair of the Admissions Committee.

Why should I apply to Caltech Astronomy?
Since its beginnings (the days of George Ellery Hale, Edwin Hubble, Fritz Zwicky, Walter Baade, Willy Fowler, Jesse Greenstein and many others), Caltech has been one of the world's premier astronomical research institutions. Here were discovered the expansion of the universe, quasars, and the theory of nucleosynthesis. The fields of infrared astronomy and VLBI were born and developed at Caltech. There are no signs of slowing down. We operate what is arguably the world's largest and finest collection of astronomical facilities over the full range of wavelengths, and graduate students have every opportunity to participate in observation and instrumentation efforts at these facilities.

The two Caltech/UC 10-meter Keck telescopes on Mauna Kea in Hawaii are the world's largest optical telescopes.  They have a wide complement of instrumentation for infrared and optical imaging and spectroscopy including for adaptive optics. Many graduate theses are partially based on Keck data, and students frequently travel to Hawaii with their advisors to assist with observing runs.

Telescopes at Palomar Observatory are used for both optical and infrared astronomy. They include the Hale 200-inch telescope, a 60-inch telescope, the 48-inch Oschin Schmidt telescope,  The 200-inch telescope is famous for its role in cosmology and in the discovery of quasars and radio galaxies. Recently-developed instruments for the 200-inch telescope include optical and infrared  array cameras for imaging and spectroscopy, and a state of the art adaptive optics system. The 60-inch are utilized for graduate thesis work, and the 60-inch is also available for independent student projects. The 48-inch Oschin Schmidt telescope, which conducted the celebrated Palomar Sky Survey in the 1950's, is now making a second complete survey of the northern sky. Both surveys are digitized, and the resulting data base will contain about 20 million galaxies and over 100 million stars. Caltech's Owens Valley Radio Observatory includes the highly productive millimeter wave interferometer (six 10-meter telescopes), which operates at both 2.7mm and 1.3mm wavelengths, and is now incorporated into CARMA array in the White Mountains to the east of the valley. A high-precision 40-m radio telescope is used for VLBI and for microwave background and pulsar studies; a new 5-meter dish is optimized for microwave background work. The Caltech Submillimeter Observatory on Mauna Kea in Hawaii has a 10-meter telescope and superb instrumentation, opening new wavebands to astronomers studying the interstellar media of our own and external galaxies. A microwave background mapping interferometer is under construction. As at Palomar, students have ample opportunity to perform their own observations and develop new instrumentation.

Caltech Solar Observatory on Big Bear Lake, one of the world's finest sites for solar work, contains a 26-inch solar telescope and a helioseismograph for studying the oscillations of the sun. Big Bear is now operated by the New Jersey Institute of Technology for a consortium of universities including Caltech, so opportunity for solar graduate work still exists. Solar astronomy is also done at the Owens Valley Radio Observatory, where a pair of 90-foot telescopes with frequency-agile receivers are used for mapping the sun's radio flares.

Caltech faculty and students have built balloon-, rocket-, and satellite-based cosmic-ray detectors and gamma-ray detectors with unique high-resolution imaging capabilities. Some of these projects include BOOMERAnG, BOLOCAM and ACBAR, ACE, NuSTAR and GALEX. In the non-electromagnetic domain, Caltech and MIT are building the world's first gravitational wave observatory, LIGO, a pair of laser interferometers with ~5 km arms. Operating in coincidence to reject noise, it is expected that these interferometers will discover gravitational radiation from astrophysical sources.

Caltech graduate students in astronomy use all of these instruments in their research, as well as the national facilities such as the VLA and Arecibo radio telescopes, telescopes at the Cerro Tololo Inter-American Observatory, and various NASA facilities, including the Hubble Space Telescope, CHANDRA and Spitzer.

Close proximity to all this observational activity inspires a vibrant Theoretical Astrophysics group. This comprises 4 faculty, plus about 10 postdoctoral fellows and a dozen graduate students. Interests range from the theory of interstellar turbulence and stellar oscillations to the physics of neutron stars, black holes, active galactic nuclei, accretion disks and cosmology.

Computational facilities are no less impressive. The Caltech astronomy department supports a network of about 100 workstations. The research groups of individual astronomy faculty members have dozens of additional Sun, MacOS, DELL servers and workstations; virtually all graduate students have a workstation on their desk. Members of the department also use the several Caltech concurrent computers (massively parallel machines, the 100Gflop Intel Paragon and the 20Gflop Delta). Graduate students have used the Caltech concurrent computers for simulations of relativistic magnetised jets, colliding galaxies and cosmology, and for reduction of optical interferometry data from the 200-inch; their ability to perform giant Fourier transforms allowed a Caltech group to discover faint binary pulsars in globular clusters and giant pulses from millisecond pulsars.

How do I finance my graduate education?
Most students are supported by the research funds of Caltech faculty, by Caltech research fellowships, and by teaching assistantships (whose duties are generally limited to solving and grading homework for a small course, though teaching and tutoring larger courses can be arranged for those interested). Admitted students are guaranteed financial support, and are not required to work for a sponsoring faculty member. Caltech is a private university, with no relation to the University of California system. There is therefore no difference in the financial support of California natives, U.S. citizens, and non-citizens. We do encourage applicants to seek outside fellowships -- e.g. NSF, NASA, Hertz, ATT fellowships for US students, government or other fellowships for foreign students, Zonta fellowships for qualifying women, etc. These confer status and lighten the load on our grants.

Should I apply in Astronomy, Physics, or Planetary Science?
Students interested primarily in planetary astronomy or geophysics should apply for admission to the Planetary Science or Geophysics option. Students interested in cosmochemistry may apply for admission either to the Astronomy option, or to the Geochemistry option, depending on their other interests. Students interested in space physics (e.g. cosmic rays) or the particle-physics/cosmology interface should generally apply for admission in Physics.

Students interested in theoretical astrophysics or in any form of observational astronomy may apply either in Astronomy or in Physics. Students in either option may work with astronomy faculty (many of whom have appointments in Physics). The primary difference between the two options is in the graduate courses required for candidacy. The Physics courses give a broad exposure to astrophysics, with emphasis on physical processes rather than descriptive astronomy. Students in either option are encouraged to take courses in the other. Historically, a slight majority of students in theoretical astrophysics, infrared astronomy, high-energy astrophysics, and gravitational radiation detector development have come from the Physics option. A larger majority of those in radio, millimeter wave, optical, and solar astronomy have come from the Astronomy option. Applicants should not pay much attention to these historical trends, however. Your choice of option should be based primarily on how certain you are that you want to be an astronomer/astrophysicist, the strength of your previous preparation in physics, and whether you feel you need more course preparation in astrophysics or in physics.

What should I have studied before coming to Caltech?
Applicants for graduate study in the astronomy option should be committed to a career in astronomy or astrophysics. Most incoming students should have a strong background in classical and quantum physics; previous exposure to astronomy is very helpful, but certainly not required for admission. We also encourage applications from students with weaker preparation in physics, but unusual backgrounds: recent graduate students in astronomy have included a chemistry major, a math major, and students who had worked in industry for several years before coming to Caltech. For those not native speakers of English: proficiency in English is essential. An exam in both written and spoken English must be passed before you can receive a teaching assistantship. You will not enjoy your courses or research if you cannot understand the lectures and seminars!

What factors are important in my application?
Everything you send is important; one or two outstanding items can outweigh several poor ones in our decisions. We look at any research work you may have done, your publications if you have any, letters of recommendation, your GRE scores, courses taken, grades, and your essay statement of purpose. Despite the limitations of standardized exams, your GRE scores (General and preferably Physics) are important. Especially for students from less well-known schools and foreign countries, they provide an important normalizing factor. Please make sure that your GRE scores reach us well before the closing date.

What are my prospects for finishing and getting a job?
Since 1980, of the students departing the Caltech graduate astronomy program, 1% of students withdrew with no degree, 10% left with an MS degree, and 88% graduated with PhDs, typically within 5 years. As of December 1996: of the 42 students who graduated from Caltech with PhDs in Astronomy in the years 1986-1996, 41 are still alive, and 36 (88%) are working in astronomy. Of these, 33% are professors, 31% are permanent scientific staff (mainly at national observatories and laboratories), and 36% (the most recent graduates) are in postdoctoral positions at major astronomical research institutes. Only 5 (12%) are employed outside astronomy. This is a better record than holds at most other major schools.

What will be my relations with faculty at Caltech?
Approximately 30 members of the Caltech faculty are involved in research in astronomy and astrophysics, as are about 30 postdoctoral fellows and research associates. There are approximately 30 graduate students in astronomy (plus another 25 physics students also doing astronomy and astrophysics). Students are encouraged to begin research as soon as they arrive. Research can be independent or with a faculty member. Each graduate student chooses a faculty advisor at the end of his or her first year at Caltech. Some students work very closely with their advisors; others are very independent. Some change advisors as their research interests evolve; some choose inter-disciplinary projects and have multiple advisors (e.g., an observer and a theorist). You do not have to work on your advisor's pet project to receive financial support. Only in the rare cases when a student fails to make significant progress in his or her chosen area of research is a student ever assigned a project.

What about the quality of life in and around Caltech?
The Caltech campus is located in the pleasant city of Pasadena, 10 miles northeast from downtown Los Angeles, at the foot of the San Gabriel Mountains. Caltech has a beautiful tree-lined campus dominated by Spanish-style architecture. There are approximately 1000 PhDs (300 faculty, 700 postdoctoral fellows), 1000 graduate students, and 800 undergraduates. The undergraduates major primarily in technical fields, but receive a broad education in the humanities as well, while graduate studies concentrate exclusively on science and engineering. Although a small school, Caltech offers a fair number of campus activities. A large number of clubs and special-interest groups are supported by the school. Grad students participate in a variety of athletic activities, ranging from competitive intercollegate club teams to highly non-competitive summer softball. Professional theatre and music groups visit campus regularly, and some 15% of the total student body performs regularly in the Caltech orchestra, chamber music program, Glee Club (choir), jazz band, wind ensemble, or musical theatre program.

In addition to Caltech, Pasadena is home to the nation's top design school, the Art Center College of Design, Pasadena City College and the Fuller Theological Seminary. Within a 2 mile circle around Caltech are located the Norton Simon Museum, and the Huntington Museum, Library and Garden, together representing one of the finest collections of European art and manuscripts in the US. Also in that circle are the Pacific Asia Museum, the unusual Kidspace interactive children's museum, and the Pasadena Playhouse (the State Theatre of California, training ground for many famous film and theater actors and origin of many shows that ultimately become Broadway hits), the trendy nightlife of Old Town Pasadena, and the Pasadena Civic Auditorium, home to the Pasadena Symphony, the Emmy Awards ceremony, and many other events. Within a 4 mile circle around Caltech are located the Southwest Museum, Eaton Canyon and Arroyo Seco recreation areas, the Los Angeles County Arboretum, the Santa Anita horse racing track, and Pasadena's celebrated Rose Bowl stadium. Pasadena is home to the distinguished Pasadena Symphony, the Coleman Chamber Music Association (whose concerts are held at Caltech), and numerous rock bands, bars, nightclubs, and comedy clubs.

Pasadena is current or original home to a large number of high-tech companies, including Earthlink, (the second-largest internet provider in the USA, now in headquartered in Atlanta), CitySearch (now in West Hollywood) , the Parsons Corporation (the nation's top engineering design firm, and its fourth-largest construction firm), Jacobs Engineering Group (NYSE:JEC), and CountryWide Credit Industries (NYSE:CCR, the nation's largest independent mortgage lender).

Slightly further afield, in the greater Los Angeles, one can find the LA Civic Center, Disney Theater (opera, theater, LA Symphony), the Hollywood Bowl, Chinatown (old and new) and the sports stadia of Los Angeles. Access to central LA is now possible by the Metro Gold Line light rail line. In a 15 mile radius are several hundred live-performance theaters, the movie studios of Hollywood, and the television studios of Burbank. Members of the Caltech community often sit in the studio audiences of popular sitcoms and attend pre-release audience-reaction screening of major films; Caltech is also a popular filming location (e.g., Beverly Hills Cop, Murder She Wrote). Disneyland, Universal Studios, Magic Mountain, and Knotts' Berry Farm are an hour's drive away. Hikers and mountain bikers enjoy the San Gabriel mountains and Angeles National Forest. An hour's drive will take you to the beaches of the Pacific Ocean, while during winter months, a 2 hour drive will take you to downhill skiing at 9,000-ft elevation.