|Author||Kameswara Rao, N. ♦ Lambert, D. L.|
|Source||Indian Institute of Astrophysics|
|Subject Domain (in DDC)||Natural sciences & mathematics ♦ Physics|
|Subject Keyword||Absorption spectra ♦ Astronomical spectroscopy ♦ Emission spectra ♦ R coronae borealis stars ♦ Charge coupled devices ♦ Chromosphere ♦ High resolution ♦ Nebulae ♦ Photosphere ♦ Spectral line width ♦ Spectral resolution|
|Description||The R Coronae Borealis star V854 Cen was observed at minimum light (V about 15) at high spectral resolution from 5480 to 7070 A. The spectrum consists of three components: a continuum devoid of photospheric lines, a collection of sharp emission lines of Sc II, Ti II, Y II, and Ba II, and broad emission lines of forbidden O I, forbidden N II, forbidden S II, H-alpha, Na D, and C2 Swan bands. A low resolution spectrum reveals additional lines of Ca II, forbidden C I, and other species. The sharp emission lines are considered to be chromospheric lines. The broad lines with a full width of 400-500 km/s come from an extended region with a temperature of about 7000 K, but an electron density of 50/cu cm or less. It is suggested that V854 Cen may be a bipolar nebula.|
|Education Level||UG and PG|
|Learning Resource Type||Article|
|Publisher Institution||American Astronomical Society|
|Size (in Bytes)||1.91 MB|
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