New variable star 18. 1902 Coronae.

The MACHO Project LMC Variable Star Inventory : IV . New R Coronae Borealis

We report the discovery of two new R Coronae Borealis (RCB) stars in the Large Magellanic Cloud (LMC) using the MACHO project photometry database. The identiication of both stars has been connrmed spectroscopically. One is a cool RCB star (T eff 5000 K) characterized by very strong Swan bands of C 2 and violet bands of CN, and weak or absent Balmer lines, G-band and 12 C 13 C bands. The second ...

The Newly Active R Coronae Borealis Star, V2552 Oph

In 2001, V2552 Oph (CD -22 12017, HadV98) quickly faded by several magnitudes in a manner typical of the R Coronae Borealis (RCB) stars. Photometry of V2552 Oph obtained over 70 years previous to 2001 shows no indication of variability. Optical spectra of this star subsequently confirmed that V2552 Oph is a member of the hydrogen deficient, carbon-rich RCB class of variables. It resembles the w...

Luminous Red Variable Star

We report photometry and spectroscopy of the evolution of Nova Sagittarii 1994 #1 (V4332 Sagittarii) during outburst. We compare the photometric and spectral evolution of this outburst to known classes of outbursts – including classical novae and outbursts occurring on symbiotic stars – and find this object does not conform to any known class of outburst. The closest match to the behavior of th...

Jets , accretion , coronae and all that : The enigmatic X - rays from the Herbig star HD 163296 ⋆ ⋆ ⋆

Context. Herbig Ae/Be stars (HAeBe) are pre-main sequence objects in the mass range 2 M⊙ < M * < 8 M⊙. Their X-ray properties are uncertain and, as yet, unexplained. Aims. We want to elucidate the X-ray generating mechanism in HAeBes. Methods. We present a XMM-Newton observation of the HAeBe HD 163296. We analyse the light curve, the broad band and the grating spectra, fit emission measures and...

Arne Tiselius, 1902-1971.