Search Publications
Discovery of a thermonuclear Type I X-ray burst in infrared: new limits on the orbital period of 4U 1728-34
Altamirano, D.; Belloni, T.; Vincentelli, F. M. +4 more
We report the detection of an infrared burst lagging a thermonuclear Type I X-ray burst from the accreting neutron star (NS) 4U 1728-34 (GX 354-0). Observations were performed simultaneously with XMM-Newton (0.7-12 keV), NuSTAR (3-79 keV), and HAWK-I@VLT (2.2 µm). We measure a lag of 4.75 ± 0.5 s between the peaks of the emission in the two …
Photometric investigation on the W-subtype contact binary V1197 Her
Soonthornthum, Boonrucksar; Zhou, Xiao
Multi-color light curves of V1197 Her were obtained with the 2.4 meter optical telescope at the Thai National Observatory and the Wilson-Devinney (W-D) program was used to model the observational light curves. The photometric solutions reveal that V1197 Her is a W-subtype shallow contact binary system with a mass ratio of q = 2.61 and a fill-out f…
NGTS-8b and NGTS-9b: two non-inflated hot Jupiters
Jackman, James A. G.; Wheatley, Peter J.; Bayliss, Daniel +36 more
We report the discovery, by the next generation transit survey (NGTS), of two hot Jupiters NGTS-8b and NGTS-9b. These orbit a V = 13.68 K0V star (Teff = 5241 ± 50 K) with a period of 2.49970 d, and a V = 12.80 F8V star (Teff = 6330 ± 130 K) in 4.43527 d, respectively. The transits were independently verified by follow-up phot…
Sunquake with a second bounce, other sunquakes, and emission associated with the X9.3 flare of 6 September 2017. I. Observations
Dammasch, Ingolf E.; Matthews, Sarah; Inoue, Satoshi +4 more
Aims: The 6 September 2017 X9.3 solar flare produced very unique observations of magnetic field transients and a few seismic responses, or sunquakes, detected by the Helioseismic and Magnetic Imager (HMI) instrument aboard Solar Dynamic Observatory (SDO) spacecraft, including the strongest sunquake ever reported. This flare was one of a few f…
Coupled day-night models of exoplanetary atmospheres
Gandhi, Siddharth; Jermyn, Adam S.
We provide a new framework to model the day side and night side atmospheres of irradiated exoplanets using 1D radiative transfer by incorporating a self-consistent heat flux carried by circulation currents (winds) between the two sides. The advantages of our model are its physical motivation and computational efficiency, which allows for an explor…
Searching for volcanic activity and a mercury-like exosphere of the super-Earth HD3167 b
Guenther, Eike W.; Kislyakova, Kristina G.
HD3167 b is a transiting super-Earth that has a density which is consistent with a rocky composition. The planet is exposed to strong radiation, intense stellar wind, and likely strong tidal forces and induction heating. According to theory, planets that are so close to the star should have an atmosphere like Mercury but much more extended and den…
The morphological, elastic, and electric properties of dust aggregates in comets: A close look at COSIMA/Rosetta's data on dust in comet 67P/Churyumov-Gerasimenko
Kimura, Hiroshi; Merouane, Sihane; Paquette, John +2 more
The Cometary Secondary Ion Mass Analyzer (COSIMA) onboard ESA's Rosetta orbiter has revealed that dust particles in the coma of comet 67P/Churyumov-Gerasimenko are aggregates of small grains. We study the morphological, elastic, and electric properties of dust aggregates in the coma of comet 67P/Churyumov-Gerasimenko using optical microscopic imag…
Probing the atmosphere of HD189733b with the Na I and K I lines
Strassmeier, K. G.; Ilyin, I.; Steffen, M. +12 more
High spectral resolution transmission spectroscopy is a powerful tool to characterize exoplanet atmospheres. Especially for hot Jupiters, this technique is highly relevant, due to their high-altitude absorption, e.g. from resonant sodium (Na I) and potassium (K I) lines. We resolve the atmospheric K I absorption on HD189733b with the aim to compar…
The elusive tidal tails of the Milky Way globular cluster NGC 7099
Carballo-Bello, Julio A.; Piatti, Andrés E.; Catelan, Márcio +3 more
We present results on the extra-tidal features of the Milky Way globular cluster NGC 7099, using deep gr photometry obtained with the Dark Energy Camera (DECam). We reached nearly 6 mag below the cluster's main sequence (MS) turnoff, so that we dealt with the most suitable candidates to trace any stellar structure located beyond the cluster tidal …
Optical Linear Polarization toward the Open Star Cluster Casado Alessi 1
Yadav, R. K. S.; Medhi, Biman J.; Pandey, Jeewan C. +1 more
We present B-, V-, R-, and I-band linear polarimetric observations of 73 stars in the direction of open star cluster Casado Alessi 1 (hereafter Alessi 1). We aim to use polarimetry as a tool to investigate the properties and distribution of dust grains toward the direction of the cluster. The polarimetric observations were carried out using the AR…