1,276 research outputs found
El Tabalet : colecsiĂł de mĂșsica alegre y divertida en solfa valensiana: NĂșmero 7 - 13 junio 1847
<!--Microfilme. Valencia : BV, ca. 199
El Tabalet : colecsiĂł de mĂșsica alegre y divertida en solfa valensiana: NĂșmero 5 - 30 mayo 1847
<!--Microfilme. Valencia : BV, ca. 199
El Tabalet : colecsiĂł de mĂșsica alegre y divertida en solfa valensiana: NĂșmero 9 - 27 junio 1847
<!--Microfilme. Valencia : BV, ca. 199
El Tabalet : colecsiĂł de mĂșsica alegre y divertida en solfa valensiana: NĂșmero 13 - 31 julio 1847
<!--Microfilme. Valencia : BV, ca. 199
Discovery of a massive variable star with Z=Zo/36 in the galaxy DDO 68
The Local Volume dwarf galaxy DDO 68, from the spectroscopy of its two
brightest HII regions (Knots 1 and 2) was designated as the second most
metal-poor star-forming galaxy [12+log(O/H)=7.14]. In the repeated spectral
observations in 2008 January with the 6-m telescope (BTA) of the HII region
Knot 3 [having 12+log(O/H)=7.10+-0.06], we find a strong evidence of a
transient event related to a massive star evolution. From the follow-up
observation with the higher spectral resolution in 2008 February, we confirm
this phenomenon, and give parameters of its emission-line spectrum comprising
of Balmer HI and HeI lines. The luminosities of the strongest transient lines
(Ha, Hb) are of a few 10^36 erg s^-1. We also detected an additional continuum
component in the new spectrum of Knot 3, which displays the spectral energy
distribution raising to ultraviolet. The estimate of the flux of this continuum
leads us to its absolute V-band magnitude of ~-7.1. Based on the spectral
properties of this transient component, we suggest that it is related to an
evolved massive star of luminous blue variable type with Z=Zo/36. We briefly
discuss observational constraints on parameters of this unique (in the aspect
of the record low metallicity of the progenitor massive star) event and propose
several lines of its study.Comment: 6 pages, 5 Postscript figures, to appear in MNRAS Letters in June
2008 issu
El Tabalet (nueva ediciĂłn): NĂșmero 4 - 23 mayo 1847
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El Tabalet (nueva ediciĂłn): NĂșmero 5 - 30 mayo 1847
<!--Microfilme. Valencia : BV, ca. 199
El Tabalet (nueva ediciĂłn): NĂșmero 12 - 18 julio 1847
<!--Microfilme. Valencia : BV, ca. 199
El Tabalet (nueva ediciĂłn): NĂșmero 9 - 27 junio 1847
<!--Microfilme. Valencia : BV, ca. 199
El Tabalet (nueva ediciĂłn): NĂșmero 3 - 16 mayo 1847
<!--Microfilme. Valencia : BV, ca. 199
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