On the stability of the radiation from the discrete radio source Cassiopeia-A in the decameter range of wavelengths

1970 ◽  
Vol 13 (10) ◽  
pp. 1136-1139
Author(s):  
E. A. Benediktov
Keyword(s):  
Radio Source ◽  
Cassiopeia A ◽  
Decameter Range ◽  
The Stability

Note on a periodic intensity variation of the radio source Cassiopeia-A

Astrophysics ◽  
2007 ◽  
Vol 50 (2) ◽  
pp. 203-206 ◽  
Author(s):  
R. M. Martirossyan ◽  
A. G. Goulyan ◽  
V. A. Sanamyan ◽  
H. A. Piroumyan
Keyword(s):  
Radio Source ◽  
Intensity Variation ◽  
Cassiopeia A ◽  
Periodic Intensity

The Radio Source Cassiopeia A

Nature ◽  
1966 ◽  
Vol 209 (5030) ◽  
pp. 1339-1340 ◽  
Author(s):  
R. MINKOWSKI
Keyword(s):  
Radio Source ◽  
Cassiopeia A

Secular Variation of the Flux Density of the Radio Source Cassiopeia A

Nature ◽  
1961 ◽  
Vol 190 (4777) ◽  
pp. 705-706 ◽  
Author(s):  
D. S. HEESCHEN ◽  
B. L. MEREDITH
Keyword(s):  
Radio Source ◽  
Flux Density ◽  
Secular Variation ◽  
Cassiopeia A

Decrease of Flux Density of the Radio Source Cassiopeia A at 81.5 MHz

Nature ◽  
1969 ◽  
Vol 223 (5211) ◽  
pp. 1139-1140 ◽  
Author(s):  
P. F. SCOTT ◽  
J. R. SHAKESHAFT ◽  
M. A. SMITH
Keyword(s):  
Radio Source ◽  
Flux Density ◽  
Cassiopeia A

Variation in the Flux Density of the Radio Source Cassiopeia-A During the Period 2007-2015

Astrophysics ◽  
2017 ◽  
Vol 60 (1) ◽  
pp. 83-89
Author(s):  
R. M. Martirosyan ◽  
A. G. Gulyan ◽  
G. A. Pirumyan ◽  
S. A. Sargsyan ◽  
G. S. Avetisyan
Keyword(s):  
Radio Source ◽  
Flux Density ◽  
Cassiopeia A

Fifteen Months of Pulsar Astronomy

1969 ◽  
Vol 1 (6) ◽  
pp. 254-263 ◽  
Author(s):  
V. Radhakrishnan
Keyword(s):  
Radio Source ◽  
Time Scales ◽  
Time Scale ◽  
Repetition Rate ◽  
Pulse Amplitude ◽  
Radio Observatory ◽  
Millisecond Time Scale ◽  
The Stability ◽  
The Individual

Towards the end of February 1968 the astronomical world was staggered by a paper from the Milliard Radio Observatory at Cambridge announcing the discovery of an astonishing periodic phenomenon. The characteristics of the pulsating radio source—or pulsar as it came to be called—involved a fantastic multiplicity of time-scales. The duration of the individual events was measured in tens of milliseconds, the repetition rate was of the order of a second, the pulse amplitude showed drastic variations over times of seconds, minutes, hours and even months and, lastly, the stability of the basic periodicity indicated a time-scale of millions of years. A series of pulses from CP 1919, the first pulsar, is shown in Figure 1, and one notices here both the regularity of the pulses and the variation in their amplitude with time. When the individual pulses were observed on an expanded time-scale it was found that the pulses were made up of sub-pulses (Figure 2) and that there was considerable structure even down to a millisecond time-scale.

An investigation of the Cassiopeia A radio-image in the decameter range

1993 ◽  
Vol 201 (1) ◽  
pp. 79-90 ◽  
Author(s):  
A. V. Megn ◽  
S. Ya. Braude ◽  
S. L. Rashkovsky ◽  
V. A. Shepelev ◽  
N. K. Sharykin ◽  
...  
Keyword(s):  
Radio Image ◽  
Cassiopeia A ◽  
Decameter Range

Secular Variation of the Flux Density of the Radio Source Cassiopeia A

Nature ◽  
1961 ◽  
Vol 189 (4764) ◽  
pp. 561-562 ◽  
Author(s):  
J. A. HÖGBOM ◽  
J. R. SHAKESHAFT
Keyword(s):  
Radio Source ◽  
Flux Density ◽  
Secular Variation ◽  
Cassiopeia A

scholarly journals RADIO STAR SCINTILLATION DURING THE JULY 20, 1963, ECLIPSE

1965 ◽  
Vol 43 (6) ◽  
pp. 1050-1058 ◽  
Author(s):  
R. S. Allen ◽  
J. A. Klobuchar ◽  
W. C. Kidd ◽  
H. E. Whitney
Keyword(s):  
Frequency Dependence ◽  
Radio Source ◽  
Solar Eclipse ◽  
Total Solar Eclipse ◽  
Radio Observatory ◽  
Cassiopeia A ◽  
Scale Size ◽  
Parabolic Antenna ◽  
Ray Path ◽  
Galactic Radio

Amplitude scintillations of the radio energy from the galactic radio source Cassiopeia A were examined for the total solar eclipse of July 20, 1963, using the 150-foot parabolic antenna at the AFCRL Sagamore Hill Radio Observatory, Hamilton, Massachusetts. The extent of eclipsing varied along the ionospheric ray path from 100% at about 100 km to about 80% near 500 km. Chart recordings of the amplitude variations of the Cassiopeia A signal were made at frequencies of 29.8, 63, 113, and 228 Mc/s. The extent of variation in amplitude and rate of scintillation was comparable to that on control days. Examination of the frequency dependence showed that the scale size of the irregularities did not change significantly during the period of the eclipse. No effects in the scintillation records could be related uniquely to the reduction of ionizing illumination and subsequent cooling of the medium.

Open discussion

1982 ◽  
Vol 99 ◽  
pp. 605-613
Author(s):  
P. S. Conti
Keyword(s):  
Buenos Aires ◽  
Large Mass ◽  
List Type ◽  
Common Phenomenon ◽  
Open Discussion ◽  
The Stability ◽  
Ring Nebulae

Conti: One of the main conclusions of the Wolf-Rayet symposium in Buenos Aires was that Wolf-Rayet stars are evolutionary products of massive objects. Some questions:–Do hot helium-rich stars, that are not Wolf-Rayet stars, exist?–What about the stability of helium rich stars of large mass? We know a helium rich star of ∼40 MO. Has the stability something to do with the wind?–Ring nebulae and bubbles : this seems to be a much more common phenomenon than we thought of some years age.–What is the origin of the subtypes? This is important to find a possible matching of scenarios to subtypes.

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