Narrow-band, slowly varying decimetric radiation from the dwarf M flare star YZ Canis Minoris

Technical Report · Sat Mar 01 04:00:00 EST 1986

OSTI ID:6955753

Lang, K R; Willson, R F

Narrow-band slowly varying microwave radiation has been detected from the dwarf M star YZ Canis Minoris at frequencies near 1465 MHz. This quiescent, or nonflaring, emission cannot be attributed to gyroresonant radiation from coronal loops; the loops would have to be more than 200 times the stellar radius in size with magnetic field strengths of H > or = 100 G at this distance. The narrow-band structure (Delta nu/nu > or = 0.1) of the slowly varying radiation cannot be explained by continuum emission processes. These observations may be explained by coherent burst mechanisms like electron-cyclotron masers or coherent plasma radiation. Maser action at the second harmonic of the gyrofrequency implies a longitudinal magnetic field strength of 250 G and an electron density of N/sub e/ = approx. 6 x 10/sup 9//cm/sup 3/. Coherent plasma radiation at the second harmonic of the plasma frequency similarly requires N/sub e/ = approx. 6 x 10/sup 9//cm/sup 3/ but a longitudinal magnetic field strength of H/sub L/ << 250 G. The slow variation of the narrow-band emission might be explained by the stochastic nature of continued low-level, coherent burst activity. There are possible analogies with narrow-band decimetric bursts observed on the Sun.

• Research Organization: Tufts Univ., Medford, MA (USA). Dept. of Physics and Astronomy
• OSTI ID: 6955753
• Report Number(s): AD-A-172937/5/XAB
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics &amp; Cosmology-- Stars &amp; Quasi-Stellar
Radio &amp; X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERES
COHERENT RADIATION
DWARF STARS
ELECTROMAGNETIC RADIATION
FREQUENCY RANGE
GHZ RANGE
GHZ RANGE 01-100
RADIATIONS
RADIOWAVE RADIATION
SHORT WAVE RADIATION
STARS
STELLAR ATMOSPHERES