Hbeta Emission Line Research Articles

Variability of NGC 1275

view Abstract Citations (13) References (30) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Variability of NGC 1275. Kingham, K. A. ; Oconnell, R. W. Abstract Broad-band B and V photoelectric photometry of NGC 1068 and 1275 covering a period of 9 months is discussed. The nucleus of NGC 1068 is nonvariable at the 0.015 mag level. NGC 1275, however, contains a highly variable nonthermal source which produces outbursts of about 0.5 mag with time scales of about 60 days. During one such event, a rapid flux decrease followed by a brightening with a rate of at least about 0.13 mag/day was observed. The spectral index of the nonthermal source does not vary significantly. Spectrophotometry obtained during one event in NGC 1275 indicates H-beta emission line variations of 60% and an increase in the forbidden O III line width by a factor of two over earlier studies. Publication: The Astronomical Journal Pub Date: October 1979 DOI: 10.1086/112571 Bibcode: 1979AJ.....84.1537K Keywords: Astronomical Photometry; Electrophotometry; Galactic Nuclei; Variability; Visual Photometry; Broadband; Emission Spectra; Line Spectra; Power Spectra; Astronomy; Galactic Nuclei:Photometry; Galactic Nuclei:Spectrophotometry; Galactic Nuclei:Variations full text sources ADS | data products NED (2) SIMBAD (1)

VARIATIONS IN THE HYDROGEN EMISSION LINES OF NOVA CYGNI 1975 (V1500 CYGNI).

ABSTRACT The H-alpha and H-beta emission lines of Nova V1500 Cyg between September 10-15, 1975, appear to show the light echo effect caused by reflection of a varying central source from a surrounding partial shell. Predictions based on a sinusoidally varying searchlight of 0.141-day period illuminating an expanding ring fit most of the observed variations quite well. The profiles indicate a clumpiness in the shell density which has also been noted by others. The H-alpha profile sharpened significantly between September 10 and October 7, 1975. Balmer line self-absorption, as proposed by Ferland (1978), can account for the large Balmer decrement observed and its velocity dependence. The latter increases inversely as the slope of the emission-line profiles and is more compatible with an emitting region in the form of an equatorial ring and polar 'blobs' rather than with a shell.