scholarly journals Comparison of Optical and Radio Positions of Stars

1990 ◽  
Vol 141 ◽  
pp. 513-514
Author(s):  
LV Morrison ◽  
RW Argyle ◽  
Y Requième ◽  
JM Mazurier
Keyword(s):  
Radio Astronomy ◽  
Reference Frames ◽  
Large Array ◽  
Astronomy Observatory ◽  
Very Large Array ◽  
Radio Astronomy Observatory ◽  
Important Link ◽  
Radio Stars

The positions of radio stars measured with respect to the VLBI network of extragalactic sources provides an important link between the optical and extragalactic reference frames. The establishment of this link was brought a stage nearer realization with the publication by Florkowski et al.(1985) of the radio positions of 20 stars measured with the Very Large Array (VLA) of the National Radio Astronomy Observatory, and the publication by Lestrade et al.(1985, 1988) of 10 stars measured with the VLBI network.

scholarly journals The early technical development of the VLA

1991 ◽  
Vol 131 ◽  
pp. 160-164 ◽  
Author(s):  
George W. Swenson
Keyword(s):  
Radio Astronomy ◽  
Technical Development ◽  
Large Array ◽  
Astronomy Observatory ◽  
University Of Illinois ◽  
Very Large Array ◽  
Radio Astronomy Observatory ◽  
Leave Of Absence ◽  
The University ◽  
Academic Year

In the spring of 1964, having qualified for a sabbattical leave from the University of Illinois and having recently completed two years as Chairman of the Visiting Committee of the National Radio Astronomy Observatory, I inquired of the NRAO staff as to whether a desk and possibly some augmentation of my University half-salary might be available at Green Bank for the following academic year. Instead I was invited to join the staff as a fulltime employee and to take a coordinating role in the development of the “very large array” as Chairman of the Design Committee. The University granted me a year’s leave of absence which eventually stretched to four years.

scholarly journals Future Spectral Line Research with the VLA

1980 ◽  
Vol 87 ◽  
pp. 627-629
Author(s):  
K. J. Johnston
Keyword(s):  
New Mexico ◽  
Spectral Line ◽  
Radio Astronomy ◽  
Molecular Species ◽  
Large Array ◽  
Astronomy Observatory ◽  
Very Large Array ◽  
Radio Astronomy Observatory ◽  
Optical Telescopes

The Very Large Array (VLA) is presently being constructed on the Plains of San Augustine near Socorro, New Mexico by the National Radio Astronomy Observatory. The purpose for which this instrument is being constructed is to produce “radio images” of resolution comparable to that of large optical telescopes. There have already been several “test” observations, some successful, using the partially completed instrument to study the molecular species of OH, H2O, and NH3 with wide bandwidths (200-1500 kHz).

scholarly journals High Resolution Maps with the VLA

1983 ◽  
Vol 103 ◽  
pp. 69-78
Author(s):  
R. C. Bignell
Keyword(s):  
New Mexico ◽  
High Resolution ◽  
Radio Astronomy ◽  
Full Time ◽  
Large Array ◽  
Astronomy Observatory ◽  
Very Large Array ◽  
Radio Astronomy Observatory ◽  
Time Operation

The Very Large Array is a radio picture making instrument operated by the National Radio Astronomy Observatory in Socorro, New Mexico. The array, which has been in full time operation for more than 2 1/2 years, operates at four main wavelengths, 1.3, 2.0, 6.0 and 20 cm with achievable resolutions of .05, .08, .25 and 0.8 arc seconds respectively.

scholarly journals Upper Limits on Sub-Arcminute Fluctuations in the CBR

1992 ◽  
Vol 9 ◽  
pp. 333-334
Author(s):  
R. B. Partridge
Keyword(s):  
New Mexico ◽  
Radio Astronomy ◽  
Angular Resolution ◽  
Aperture Synthesis ◽  
Large Array ◽  
Astronomy Observatory ◽  
Very Large Array ◽  
Radio Astronomy Observatory ◽  
Upper Limits

The use of aperture synthesis allows one to search for fluctuations in the CBR on angular scales below 1 arcminute. I report here tentative results of an experiment carried out with E. B. Fomalont, R. Windhorst and J. Lowenthal using the Very Large Array of the National Radio Astronomy Observatory in New Mexico. We used the instrument in its tightest configuration and at a wavelength of 3.6 cm; the corresponding angular resolution was ~10”. We were able to set limits on fluctuations in the CBR on a range of angular scales, 10”-90”, and these are among the most sensitive upper limits on CBR fluctuations yet published.

Observations at the Mullard Radio Astronomy Observatory, Cambridge

1958 ◽  
Vol 248 (1252) ◽  
pp. 3-9 ◽  
Keyword(s):  
Radio Astronomy ◽  
Doppler Shift ◽  
Second Harmonic ◽  
Astronomy Observatory ◽  
Cavendish Laboratory ◽  
Radio Astronomy Observatory ◽  
Satellite Transmission ◽  
To Receive ◽  
Radio Stars

When the news of the launching of the first satellite was received at Cambridge, we were not aware of any plans for radio observations in this country. Such observa­tions seemed likely to be important: ( a ) In order to provide approximate information on the orbit so that accurate visual and radar observations might be made. ( b ) Because the presence of a transmitter at varying heights and zenith angles offered possibilities for ionospheric investigation. We therefore planned a series of observations which eventually engaged most of the radio astronomy group, and a large part of the ionosphere group of the Cavendish Laboratory. The first observations were aimed at the determination of an approximate orbit, and an interferometer normally used for observing radio stars at a frequency of 38 Mc/s was modified to receive the 40 Mc/s satellite transmission. This instrument was in operation on the night of 5 to 6 October, and a 40 Mc/s receiver for measuring the Doppler shift was installed the following day. A 20 Mc/s interferometer was added for ionospheric investigation, and receivers for measuring the apparent changes of intensity were later installed for 20, 40 and 80 Mc/s, the last being used on the second harmonic of the 40 Mc/s transmitter.

scholarly journals Design, environmental and sustainability constraints of new African observatories: The example of the Mozambique Radio Astronomy Observatory

2013 Africon ◽  
2013 ◽  
Author(s):  
Domingos Barbosa ◽  
Miguel Bergano ◽  
Valerio A. R. M. Ribeiro ◽  
Anita Loots ◽  
Venkatasubramani L. Thondikulam ◽  
...  
Keyword(s):  
Radio Astronomy ◽  
Astronomy Observatory ◽  
Radio Astronomy Observatory

scholarly journals On the peculiarities in the spin-down of isolated radio pulsars

2012 ◽  
Vol 8 (S291) ◽  
pp. 208-208
Author(s):  
Augustine Chukwude
Keyword(s):  
Radio Astronomy ◽  
Time Resolution ◽  
Local Phase ◽  
Astronomy Observatory ◽  
Radio Pulsars ◽  
Short Term ◽  
Radio Astronomy Observatory ◽  
Long Term Changes ◽  
Timing Data

AbstractWe investigate the spin-down behaviour of a sample of 25 radio pulsars on decadal timescales (~ 18 years) using a continuous timing data obtained over a period of at Hartebeesthoek Radio Astronomy Observatory (HartRAO). Particular attention is placed on achieving a better time resolution of both the short-term and long-term changes in pulsar spin-down using local phase-coherent measurements of the spin-down rates (). We demonstrate that the spin-down of radio pulsars is generally complicated by a superposition of processes that may or may not be related. Specifically, our results show that (i) for 7 pulsars, the observed spin-down variation is largely stochastic, characterized by random and sustained jumps in of varying amplitudes, (ii) for 9 objects, the spin-down evolution shows dominant monotonic variations in superimposed on short-term stochastic jumps in the parameter, and (iii) for the remaining 9 pulsars, the long-term spin-down evolution is non-monotonic, dominated by some systematic excursion in the measured spin-down rates.

A Wideband Superconducting Filter Using Strong Coupling Resonators for Radio Astronomy Observatory

2009 ◽  
Vol 57 (7) ◽  
pp. 1783-1789 ◽  
Author(s):  
Tao Yu ◽  
Chunguang Li ◽  
Fei Li ◽  
Qiang Zhang ◽  
Liang Sun ◽  
...  
Keyword(s):  
Strong Coupling ◽  
Radio Astronomy ◽  
Astronomy Observatory ◽  
Radio Astronomy Observatory
Sign in / Sign up

Export Citation Format

Share Document