Owens Valley Radio Observatory

Owens Valley Radio Observatory (OVRO) is a radio astronomy observatory located near Big Pine, California (USA) in Owens Valley. It lies east of the Sierra Nevada approximately 350 kilometers (220 mi) north of Los Angeles and 20 kilometers (12 mi) southeast of Bishop. It was established in 1958, and is owned and operated by the California Institute of Technology (Caltech).

One of the ten dish-antenna radiotelescope systems of the Very Long Baseline Array is immediately adjacent to, but not part of, the Owens Valley observatory.

About

Several radio telescopes of the Owens Valley Radio Observatory with the Sierra Nevada range in the background

The Owens Valley Radio Observatory (OVRO), the largest university-operated radio observatory, came to life in the late 1940s through the influence of three individuals: Lee DuBridge, president of Caltech; Robert Bacher, chairman of the Division of Physics, Mathematics and Astronomy; and Jesse Greenstein, professor of astrophysics. In 1954, Caltech occupied a central position in the American radio astronomy program. John Bolton and Gordon Stanley, two respected Australian astronomers, joined the Caltech faculty in order to undertake the construction of large dishes. In 1956 the first radio telescope, a 32-foot antenna, was erected on Palomar Mountain. It was dismantled in 1958 and transferred to the Owens Valley site. At the same time, two 90-foot (27-meter) telescopes were completed. Ten years later, an even bigger antenna, a 130-foot (40-meter) dish was finished. It was originally built to study radio galaxies but is now used to look at the sun's magnetic field. The last major instrument at the observatory is the millimeter-wave array. It consists of six 34-foot (10.4-meter) dishes (also called Leighton's dishes).

OVRO, owned by Caltech, is one of the biggest radio observatories owned by a university.^[1] OVRO uses its telescopes and other instruments (listed below) to improve on the locations of radio sources in the sky, as well as to study hydrogen clouds within the Milky Way.^[1] The research that takes place at the observatory includes studies on blazars, the cosmic microwave background, and star-formation, and this research is done by the staff at the observatory with help from professors and post-doctoral students from many institutions. The observatory is different from other national radio observatories because of its extensive work with graduate students, who can come to the observatory for long-term observation, benefitting not only the students, but also the observatory as it allows for more comprehensive projects to take place^[1]

CARMA

OVRO staff is largely responsible for operating CARMA, which is located 20 miles east of OVRO in the Inyo Mountains. CARMA is a collaboration between Caltech, University of California Berkeley, University of Illinois, University of Maryland, and University of Chicago to observe space at centimeter and millimeter wavelengths with a 23-element interferometer. CARMA uses this interferometer to study the origins of planets, stars and galaxies, as well as to measure the distortions in the cosmic microwave background caused by clusters of galaxies formed soon after the Big Bang. ^[1]

Instruments

• The Combined Array for Research in Millimeter-wave Astronomy (CARMA) is a 23-antenna interferometer located at Cedar Flat in Westgard Pass, approximately 13 km (8.1 mi) east of the main OVRO site at 2,196 m (7,205 ft). It incorporates dishes from the MMA, the former Berkeley-Illinois-Maryland Association array at Hat Creek Radio Observatory, and the Sunyaev–Zel'dovich Array.^[2]
• The OVRO 40 meter Telescope was built in 1968 and is currently used to monitor blazars.^[3]
• The C-Band All Sky Survey (C-BASS) is a 6.1 m (20 ft) telescope being used to survey the sky in the c-band in support of cosmic background radiation research.^[4] A unique feature of the telescope is the use of radio-transparent foam to support the secondary mirror. The telescope began operating in 2009.^[5]
• The Korean Solar Radio Burst Locator (KSRBL) is a 2.1 m (6.9 ft) radio telescope that is designed to detect and locate radio bursts on the Sun. It is operating as prototype at OVRO, and when it begins routine operations it will be moved to the Korea Astronomy and Space Science Institute (KASI), which funded its development.^[6]

Former instruments

• The Huan Tran Telescope (HTT) is the primary instrument of the Polarbear project to measure the polarization of the cosmic microwave background radiation. It is a 3.5 m (11 ft) Gregorian telescope with bolometers cooled to less than 1 K (−458 °F). HHT was first installed for testing at the CARMA site in 2010. It was moved to Llano de Chajnantor Observatory in 2011 and is expected to start operating in early 2012. It was developed by a consortium led by the University of California, Berkeley.^[7]
• The Owens Valley Solar Array (OVSA) was a seven-dish solar radio telescope array located at the main OVRO site until 2008. It was built by Caltech and was operated by the New Jersey Institute of Technology (NJIT) from 1997. It consisted of two 27.5 m (90 ft) antennas and five 1.8 m (5.9 ft) antennas. The OVSA antennas are being incorporated into EOVSA in a different configuration.^[8]
• The FASR Subsystem Testbed (FST) was an interferometer which used three of the 1.8 m antennas from OVSA, but upgraded with a different electronics package. It operated from 2006 until 2008.^[9]
• The Millimeter Array (MMA) was a six-element radio telescope array located at the main OVRO site until 2005, when the dishes were moved to Cedar Flat and incorporated into CARMA.^[2]
• The Solar Radio Burst Locator (SRBL) was a 1.8 m (5.9 ft) radio telescope that operated at OVRO from 1998 until 2006. It identified radio bursts from the Sun using a single dish.^[10]

Future Instruments

• The Evolved Owens Valley Solar Array (EOVSA) is a solar radio telescope array currently under construction at OVRO. It will incorporate seven refurbished dishes from OVSA, along with eight new 2 m (6.6 ft) antennas. The small dishes will be arranged in a spiral pattern instead of the typical three-arm pattern.^[11]
• The Frequency-Agile Solar Radiotelescope (FASR) is a proposed solar radio telescope array that will incorporate 75 elements.^[12]
• The Ku-Band Experiment (KuBE) is a proposed 6 m (20 ft) radio telescope with the same objective as C-BASS, but would operate in the Ku-band.^[13]
• The Owens Valley Long Wavelength Array is a remote Long Wavelength Array site with 256 22-88 MHz elements under construction with more planned.^[14]

In popular culture

In the 1996 film The Arrival, Zane Zaminsky (Charlie Sheen) and Calvin (Richard Schiff) work at Owens Valley for the SETI Project and discover an alien signal. Later in the movie one of the antennas is destroyed by a BHB (Black Hole Bomb) to prevent Zane from transmitting a tape containing proof of the aliens' plan to terraform the earth.

In Contact (1997), Eleanor Arroway (Jodie Foster) did her thesis work on the Owens Valley 40-meter telescope.

See also

Wikimedia Commons has media related to Owens Valley Radio Observatory.

• Atacama Large Millimeter Array
• List of radio telescopes
• List of observatories

References

External links

• Official website