Search Publications
Spatially resolved spectroscopy across stellar surfaces. III. Photospheric Fe I lines across HD 189733A (K1 V)
Ludwig, Hans-Günter; Dravins, Dainis; Gustavsson, Martin
Context. Spectroscopy across spatially resolved stellar surfaces reveals spectral line profiles free from rotational broadening, whose gradual changes from disk center toward the stellar limb reflect an atmospheric fine structure that is possible to model by 3D hydrodynamics.
Aims: Previous studies of photospheric spectral lines across stella…
Suzaku X-ray observations of the mixed-morphology supernova remnant CTB 1
Takahashi, Tadayuki; Uchida, Hiroyuki; Uchiyama, Yasunobu +6 more
We present an X-ray study of the mixed-morphology supernova remnant CTB 1 (G116.9+0.2) observed with Suzaku. The 0.6-2.0 keV spectra in the northeastern breakout region of CTB 1 are well represented by a collisional ionization-equilibrium plasma model with an electron temperature of ∼0.3 keV, whereas those in the southwestern inner-shell region ca…
The Long-term Secular Mass Accretion Rate of the Recurrent Nova T Pyxidis
Williams, Robert E.; Sion, Edward M.; Godon, Patrick +1 more
We present Hubble Space Telescope ultraviolet spectroscopy of the recurrent nova T Pyxidis obtained more than five years after its 2011 outburst, indicating that the system might not have yet reached its deep quiescent state. The ultraviolet data exhibit a 20% decline in the continuum flux from the pre-outburst deep quiescence state to the post-ou…
Atmospheric mass-loss of extrasolar planets orbiting magnetically active host stars
Schmitt, J. H. M. M.; Lalitha, Sairam; Dash, Spandan
Magnetic stellar activity of exoplanet hosts can lead to the production of large amounts of high-energy emission, which irradiates extrasolar planets, located in the immediate vicinity of such stars. This radiation is absorbed in the planets' upper atmospheres, which consequently heat up and evaporate, possibly leading to an irradiation-induced ma…
Molecular Gas toward the Gemini OB1 Molecular Cloud Complex. II. CO Outflow Candidates with Possible WISE Associations
Xu, Ye; Yang, Ji; Wang, Chen +4 more
We present a large-scale survey of CO outflows in the Gem OB1 molecular cloud complex and its surroundings, using the Purple Mountain Observatory Delingha 13.7 m telescope. A total of 198 outflow candidates were identified over a large area (∼58.5 square degrees), of which 193 are newly detected. Approximately 68% (134/198) are associated with the…
Possible Association of Two Stellar Bowshocks with Unidentified Fermi Sources
Luque-Escamilla, P. L.; Romero, G. E.; Martí, J. +2 more
The bowshocks of runaway stars had been theoretically proposed as gamma-ray sources. However, this hypothesis has not been confirmed by observations to date. In this paper, we present two runaway stars (λ Cep and LS 2355) whose bowshocks are coincident with the unidentified Fermi gamma-ray sources 3FLG J2210.1+5925 and 3FGL J1128.7-6232, respectiv…
When nature tries to trick us. An eclipsing eccentric close binary superposed on the central star of the planetary nebula M 3-2
Jones, David; Miszalski, Brent; Saviane, Ivo +7 more
Bipolar planetary nebulae (PNe) are thought to result from binary star interactions and, indeed, tens of binary central stars of PNe have been found, in particular using photometric time-series that allow for the detection of post-common envelope systems. Using photometry at the NTT in La Silla we have studied the bright object close to the centre…
Physics of a clumpy lensed galaxy at z = 1.6
Schaerer, D.; Dessauges-Zavadsky, M.; Cava, A. +3 more
Observations have shown that massive star-forming clumps are present in the internal structure of high-redshift galaxies. One way to study these clumps in detail with a higher spatial resolution is by exploiting the power of strong gravitational lensing which stretches images on the sky. In this work, we present an analysis of the clumpy galaxy A6…
HATS-50b through HATS-53b: Four Transiting Hot Jupiters Orbiting G-type Stars Discovered by the HATSouth Survey
Henning, Th.; Mancini, L.; Rabus, M. +26 more
We report the discovery of four close-in transiting exoplanets (HATS-50b through HATS-53b), discovered using the HATSouth three-continent network of homogeneous and automated telescopes. These new exoplanets belong to the class of hot Jupiters and orbit G-type dwarf stars, with brightness in the range V = 12.5-14.0 mag. While HATS-53 has many phys…
Discovery of New Coronal Lines at 2.843 and 2.853 µm
DeLuca, Edward E.; Judge, Philip G.; Samra, Jenna E. +1 more
Two new emission features were observed during the 2017 August 21 total solar eclipse by a novel spectrometer, the Airborne Infrared Spectrometer (AIR-Spec), flown at 14.3 km altitude aboard the NCAR Gulfstream-V aircraft. We derive wavelengths in air of 2.8427 ± 0.00009 µm and 2.8529 ± 0.00008 µm. One of these lines belongs to the 3{{…