Photoelectric spectrophotometry of the heads of three comets.

Abstract

view Abstract Citations (2) References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Photoelectric spectrophotometry of the heads of three comets. Liller, William Abstract During 1957 the appearance of three naked- eye comets (Arend-Roland, Mrkos, and Encke) made possible a detailed study of their heads with photoelectric techniques. Comet ArendRoland was observed from X3400 to X6400 on eight nights during a period extending approximately 2.5 months on either side of the time of perihelion passage. The C2 bands were found to have reached a maximum brightness with respect to the underlying continuum approximately four weeks after closest approach to the sun, when the heliocentric distance to the comet was about 0.75 a.u. Beyond 1.2 a.u. from the sun, the intensity of the C2 relative to the continuum appears to have remained a few per cent brighter after perihelion passage than before. On three nights the head of Comet Mrkos was scanned from X3400 to ~64oo, and on one of these nights the red and infrared spectrum from X6400 to ~I2,000 was also observed. The shorter wave length region is nearly identical in appearance to that of Comet Arend-Roland when at the same solar distance. In the infrared the Av = 0 and Av = I bands of the red system of CN at XII ,ooo and X9200, respectively, seem to have been observed for the first time. The Av = 2 band of CN at X8ooo was the only other emission feature observed. Spectral sweeps of Comet Encke from X3400 to X6400 were made on two nights, and the faintness of the continuum is particularly striking. University of Michigan Observatory, Ann Arbor, Mich. Publication: The Astronomical Journal Pub Date: September 1958 DOI: 10.1086/107757 Bibcode: 1958AJ.....63..307L full text sources ADS |