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7 papers found.
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Serendipitous Kepler observations of a background dwarf nova of SU UMa type

We have discovered a dwarf nova (DN) of type SU UMa in Kepler data which is 7.0 arcsec from the G-type exoplanet survey target KIC 4378554. The DN appears as a background source in the pixel aperture of the foreground G star. We extracted only the pixels where the DN is present and observed the source to undergo five outbursts – one a superoutburst – over a time span of 22 months...

Determining the extragalactic extinction law with SALT*

We present CCD imaging observations of early-type galaxies with dark lanes obtained with the Southern African Large Telescope (SALT) during its performance-verification phase. The observations were performed in six spectral bands that span the spectral range from the near-ultraviolet atmospheric cut-off to the near-infrared. We derive the extinction law by the extragalactic dust...

Polarized QPOs from the INTEGRAL polar IGRJ14536-5522 (=Swift J1453.4-5524)

We report optical spectroscopy and high-speed photometry and polarimetry of the INTEGRAL source IGRJ14536-5522 (=Swift J1453.4-5524). The photometry, polarimetry and spectroscopy are modulated on an orbital period of 3.1564(1) h. Orbital circularly polarized modulations are seen from ∼0 to ∼−18 per cent, unambiguously identifying IGRJ14536-5522 as a polar. The negative circular...

The polar ring galaxy AM1934−563 revisited*

We report long-slit spectroscopic observations of the dust-lane polar ring galaxy AM1934−563 obtained with the Southern African Large Telescope (SALT) during its performance verification phase. The observations target the spectral region of the Hα, [N ii] and [S ii] emission lines, but also show deep Na i absorption lines, that we interpret as being produced by stars in the...

The metallicity extremes of the Sagittarius dSph: SALT spectroscopy of PNe*

In this work we present the first spectroscopic results obtained with the Southern African Large Telescope (SALT) during its performance-verification phase. We find that the Sagittarius dwarf spheroidal galaxy (Sgr) contains a youngest stellar population with [O/H]≈−0.2 and age t > 1 Gyr, and an oldest population with [O/H] =−2.0. The values are based on spectra of two planetary...

Transit timing observations from Kepler – III. Confirmation of four multiple planet systems by a Fourier-domain study of anticorrelated transit timing variations

Christopher K. Middour Robert L. Morris Fergal R. Mullally Samuel N. Quinn Elisa V. Quintana Avi Shporer Martin Still Peter Tenenbaum Susan E. Thompson Joseph D. Twicken Jeffery Van Cleve 0 Hubble Fellow We