Possible contribution of a solar transient to enhanced scintillation of a quasar

• Published in: Earth, moon, and planets Vol. 58; no. 1; pp. 31 - 38
• Main Authors: JANARDHAN, P, ALURKAR, S. K
• Format: Journal Article
• Language: English
• Published: Boston Reidel 01-07-1992; Dordrecht
• Subjects: Astronomy; Earth, ocean, space; Exact sciences and technology; Interplanetary space; Solar system; Quasar; Scintillation index; Data analysis; Cometary plasma; Interplanetary scintillation; Power spectrum
• ISSN: 0167-9295; 1573-0794
• DOI: 10.1007/BF00058071

Observations of the quasar 2314 + 038 were carried out during 16-21 December, 1985 at a solar elongation around 85 deg, when the plasma tail of Comet Halley swept in front of it. These observations have shown a two-fold increase in scintillation index as compared to the expected levels of scintillation for the source, computed using the well-known RKH (Readhead et al., 1978) model. Spacecraft data and the geomagnetic indices available during the period show that a shock-front had reached the earth on the 18 December, the day when maximum increase in scintillation was recorded. The possible contribution of such a shock-front to the enhancement has been shown to be not greater than 15 percent. Hence, the major contribution to the enhancement came from the plasma tail of a comet. (Author)