The very-long-baseline array

Journal Article · Fri Jan 01 00:00:00 EST 1988 · Scientific American; (USA)

DOI:https://doi.org/10.1038/scientificamerican0188-54· OSTI ID:6852070

Kellermann, K I; Thompson, A R

The development of radio technology in World War II opened a completely new window on the universe. When astronomers turned radio antennas to the heavens, they began to find a previously unknown universe of solar and planetary radio bursts, quasars, pulsars, radio galaxies, giant molecular clouds and cosmic masers. Not only do the radio waves reveal a new world of astronomical phenomena but also-because they are much longer than light waves-they are not as severely distorted by atmospheric turbulence or small imperfections in the telescope. About 25 years ago radio astronomers became aware that they could synthesize a resolution equivalent to that of a large aperture by combining data from smaller radio antennas that are widely separated. The effective aperture size would be about equal to the largest separation between the antennas. The technique is called synthesis imaging and is based on the principles of interferometry. Radio astronomers in the U.S. are now building a synthesis radio telescope called the Very-Long-Baseline Array, or VLBA. With 10 antennas sited across the country from the Virgin Islands to Hawaii, it will synthesize a radio antenna 8,000 kilometers across, nearly the diameter of the earth. The VLBA'S angular resolution will be less than a thousandth of an arc-second-about three orders of magnitude better than that of the largest conventional ground-based optical telescopes. Astronomers eagerly await the completion early in the next decade of the VLBA, which is expected, among other things, to give an unprecedentedly clear view into the cores of quasars and galactic nuclei and to reveal details of the processe-thought to be powered by black holes-that drive them.

• OSTI ID: 6852070
• Journal Information: Scientific American; (USA), Vol. 258:1; ISSN 0036-8733
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
RADIOASTRONOMY
MEASURING INSTRUMENTS
ANTENNAS
COSMIC RADIO SOURCES
DISTANCE
GALAXY NUCLEI
INTERFEROMETRY
INTERPLANETARY SPACE
PLASMA JETS
QUASARS
RADIO GALAXIES
RADIO TELESCOPES
RADIOWAVE RADIATION
STAR EVOLUTION
TECHNOLOGY ASSESSMENT
USES
ASTRONOMY
ELECTRICAL EQUIPMENT
ELECTROMAGNETIC RADIATION
ELECTRONIC EQUIPMENT
EQUIPMENT
GALAXIES
RADIATIONS
RADIO EQUIPMENT
SPACE
TELESCOPES
640100* - Astrophysics & Cosmology