Search Publications
On Venus' cloud top chemistry, convective activity and topography: A perspective from HST
Bertaux, Jean-Loup; Marcq, Emmanuel; Limaye, Sanjay +3 more
Hubble Space Telescope Imaging Spectrograph (HST/STIS) observations were obtained on 3 dates in December 2010 and January 2011 recording the cloud top properties over Aphrodite Terra and a low elevation region downwind of Aphrodite through LSTs extending from 7 to 11 a.m. From these data we trace the cloud top sulfur-oxide chemistry and UV albedo …
Atmospheric Characterization and Further Orbital Modeling of κ Andromeda b
Currie, Thayne; De Rosa, Robert J.; Kwon, Jungmi +19 more
We present κ Andromeda b’s photometry and astrometry taken with Subaru/SCExAO+HiCIAO and Keck/NIRC2, combined with recently published SCExAO/CHARIS low-resolution spectroscopy and published thermal infrared photometry to further constrain the companion’s atmospheric properties and orbit. The Y/Y-K colors of κ And b are redder than field dwarfs, co…
PHAT XX. AGB Stars and Other Cool Giants in M31 Star Clusters
Dolphin, Andrew E.; Skillman, Evan D.; Williams, Benjamin F. +20 more
The presence of asymptotic giant branch (AGB) stars in clusters provides key constraints for stellar models, as has been demonstrated with historical data from the Magellanic Clouds. In this work, we look for candidate AGB stars in M31 star clusters from the Panchromatic Hubble Andromeda Treasury survey. Our photometric criteria selects stars brig…
Atacama Compact Array observations of the pulsar-wind nebula of SNR 0540-69.3
Lundqvist, P.; Olofsson, G.; Zyuzin, D. A. +6 more
We present observations of the pulsar-wind nebula (PWN) region of SNR 0540-69.3. The observations were made with the Atacama Compact Array (ACA) in Bands 4 and 6. We also add radio observations from the Australia Compact Array at 3 cm. For 1.449-233.50 GHz, we obtain a synchrotron spectrum $F_{\nu } \propto \nu ^{-\alpha _{\nu }}$ , with the spect…
Comprehensive Characterization of Solar Eruptions with Remote and In-Situ Observations, and Modeling: The Major Solar Events on 4 November 2015
Veronig, Astrid M.; Nitta, Nariaki V.; Dresing, Nina +12 more
Solar energetic particles (SEPs) are an important product of solar activity. They are connected to solar active regions and flares, coronal mass ejections (CMEs), EUV waves, shocks, Type II and III radio emissions, and X-ray bursts. These phenomena are major probes of the partition of energy in solar eruptions, as well as for the organization, dyn…
SALT revisits DY Cen: a rapidly evolving strontium-rich single helium star
Rao, N. Kameswara; Lambert, David L.; Jeffery, C. Simon
The hydrogen-deficient star DY Cen has been reported as an R CrB-type variable, an extreme helium star (with some hydrogen), and as a single-lined spectroscopic binary. It has been associated with a dramatic change in visual brightness and colour corresponding to a change in effective temperature ( Teff) of some 20 000 K in the last cen…
Unveiling the stellar origin of the Wolf-Rayet nebula NGC 6888 through infrared observations
Guerrero, M. A.; Toalá, J. A.; Santamaría, E. +5 more
We present a comprehensive infrared (IR) study of the iconic Wolf-Rayet (WR) wind-blown bubble NGC 6888 around WR 136. We use Wide-field Infrared Survey Explorer, Spitzer IRAC, and MIPS and Herschel PACS IR images to produce a sharp view of the distribution of dust around WR 136. We complement these IR photometric observations with Spitzer IRS spe…
An extremely hot white dwarf with a rapidly rotating K-type subgiant companion: UCAC2 46706450
Rebassa-Mansergas, Alberto; Pelisoli, Ingrid; Irawati, Puji +5 more
The subgiant UCAC2 46706450 is a late-type star with an ultraviolet (UV) excess. It was considered as a candidate to establish a sample of stars of spectral type F, G, and K with white dwarf (WD) companions that could be used to test binary evolution models. To verify the WD nature of the companion, UV spectroscopy has previously been performed by…
Evidence for Resonance Scattering in the X-Ray Grating Spectrum of the Supernova Remnant N49
Gu, Liyi; Uchida, Hiroyuki; Tsuru, Takeshi Go +2 more
Resonance scattering (RS) is an important process in astronomical objects, because it affects measurements of elemental abundances and distorts surface brightness of the object. It is predicted that RS can occur in plasmas of supernova remnants (SNRs). Although several authors reported hints of RS in SNRs, no strong observational evidence has been…
Eclipse time variations in the post-common envelope binary V470 Cam
Lynas-Gray, A. E.; Clarke, F.; Bogensberger, D. +1 more
Linear or quadratic relations fitted to the time-dependence of post-common envelope binary eclipse times generally give residuals exhibiting a cyclic variation. Among several possible explanations is the presence of one or more orbiting circumbinary objects causing a reflex motion of the binary centre-of-mass, thereby altering the light-travel-tim…